com.unity.netcode.gameobjects@2.0.0-pre.1

The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/) and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

Additional documentation and release notes are available at [Multiplayer Documentation](https://docs-multiplayer.unity3d.com).

## [2.0.0-pre.1] - 2024-06-17

### Added

- Added event `NetworkManager.OnSessionOwnerPromoted` that is invoked when a new session owner promotion occurs. (#2948)
- Added `NetworkRigidBodyBase.GetLinearVelocity` and `NetworkRigidBodyBase.SetLinearVelocity` convenience/helper methods. (#2948)
- Added `NetworkRigidBodyBase.GetAngularVelocity` and `NetworkRigidBodyBase.SetAngularVelocity` convenience/helper methods. (#2948)

### Fixed

- Fixed issue when `NetworkTransform` half float precision is enabled and ownership changes the current base position was not being synchronized. (#2948)
- Fixed issue where `OnClientConnected` not being invoked on the session owner when connecting to a new distributed authority session. (#2948)
- Fixed issue where Rigidbody micro-motion (i.e. relatively small velocities) would result in non-authority instances slightly stuttering as the body would come to a rest (i.e. no motion). Now, the threshold value can increase at higher velocities and can decrease slightly below the provided threshold to account for this. (#2948)

### Changed

- Changed the client's owned objects is now returned (`NetworkClient` and `NetworkSpawnManager`) as an array as opposed to a list for performance purposes. (#2948)
- Changed `NetworkTransfrom.TryCommitTransformToServer` to be internal as it will be removed by the final 2.0.0 release. (#2948)
- Changed `NetworkTransformEditor.OnEnable` to a virtual method to be able to customize a `NetworkTransform` derived class by creating a derived editor control from `NetworkTransformEditor`. (#2948)

CHANGELOG.md

@@ -6,6 +6,40 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 
 Additional documentation and release notes are available at [Multiplayer Documentation](https://docs-multiplayer.unity3d.com).
 
+## [2.0.0-pre.1] - 2024-06-17
+
+### Added
+
+- Added event `NetworkManager.OnSessionOwnerPromoted` that is invoked when a new session owner promotion occurs. (#2948)
+- Added `NetworkRigidBodyBase.GetLinearVelocity` and `NetworkRigidBodyBase.SetLinearVelocity` convenience/helper methods. (#2948)
+- Added `NetworkRigidBodyBase.GetAngularVelocity` and `NetworkRigidBodyBase.SetAngularVelocity` convenience/helper methods. (#2948)
+
+### Fixed
+
+- Fixed issue when `NetworkTransform` half float precision is enabled and ownership changes the current base position was not being synchronized. (#2948)
+- Fixed issue where `OnClientConnected` not being invoked on the session owner when connecting to a new distributed authority session. (#2948)
+- Fixed issue where Rigidbody micro-motion (i.e. relatively small velocities) would result in non-authority instances slightly stuttering as the body would come to a rest (i.e. no motion). Now, the threshold value can increase at higher velocities and can decrease slightly below the provided threshold to account for this. (#2948)
+
+### Changed
+
+- Changed the client's owned objects is now returned (`NetworkClient` and `NetworkSpawnManager`) as an array as opposed to a list for performance purposes. (#2948)
+- Changed `NetworkTransfrom.TryCommitTransformToServer` to be internal as it will be removed by the final 2.0.0 release. (#2948)
+- Changed `NetworkTransformEditor.OnEnable` to a virtual method to be able to customize a `NetworkTransform` derived class by creating a derived editor control from `NetworkTransformEditor`. (#2948)
+
+
+## [2.0.0-exp.5] - 2024-06-03
+
+### Added
+
+
+### Fixed
+
+- Fixed issue where SessionOwner message was being treated as a new entry for the new message indexing when it should have been ordinally sorted with the legacy message indices. (#2942)
+
+### Changed
+- Changed `FastBufferReader` and `FastBufferWriter` so that they always ensure the length of items serialized is always serialized as an `uint` and added a check before casting for safe reading and writing.(#2946)
+
+
 ## [2.0.0-exp.4] - 2024-05-31
 
 ### Added

Components.meta

@@ -1,8 +0,0 @@
-fileFormatVersion: 2
-guid: 8b267eb841a574dc083ac248a95d4443
-folderAsset: yes
-DefaultImporter:
-  externalObjects: {}
-  userData: 
-  assetBundleName: 
-  assetBundleVariant: 

Editor/CodeGen/NetworkBehaviourILPP.cs

@@ -721,7 +721,7 @@ namespace Unity.Netcode.Editor.CodeGen
                     continue;
                 }
 
-                if (networkVariableSerializationTypesTypeDef == null && netcodeTypeDef.Name == nameof(NetworkVariableSerializationTypes))
+                if (networkVariableSerializationTypesTypeDef == null && netcodeTypeDef.Name == nameof(NetworkVariableSerializationTypedInitializers))
                 {
                     networkVariableSerializationTypesTypeDef = netcodeTypeDef;
                     continue;
@@ -1007,103 +1007,103 @@ namespace Unity.Netcode.Editor.CodeGen
 
                 switch (method.Name)
                 {
-                    case nameof(NetworkVariableSerializationTypes.InitializeSerializer_UnmanagedByMemcpy):
+                    case nameof(NetworkVariableSerializationTypedInitializers.InitializeSerializer_UnmanagedByMemcpy):
                         m_NetworkVariableSerializationTypes_InitializeSerializer_UnmanagedByMemcpy_MethodRef = method;
                         break;
-                    case nameof(NetworkVariableSerializationTypes.InitializeSerializer_UnmanagedByMemcpyArray):
+                    case nameof(NetworkVariableSerializationTypedInitializers.InitializeSerializer_UnmanagedByMemcpyArray):
                         m_NetworkVariableSerializationTypes_InitializeSerializer_UnmanagedByMemcpyArray_MethodRef = method;
                         break;
 
 #if UNITY_NETCODE_NATIVE_COLLECTION_SUPPORT
-                    case nameof(NetworkVariableSerializationTypes.InitializeSerializer_UnmanagedByMemcpyList):
+                    case nameof(NetworkVariableSerializationTypedInitializers.InitializeSerializer_UnmanagedByMemcpyList):
                         m_NetworkVariableSerializationTypes_InitializeSerializer_UnmanagedByMemcpyList_MethodRef = method;
                         break;
 #endif
-                    case nameof(NetworkVariableSerializationTypes.InitializeSerializer_UnmanagedINetworkSerializable):
+                    case nameof(NetworkVariableSerializationTypedInitializers.InitializeSerializer_UnmanagedINetworkSerializable):
                         m_NetworkVariableSerializationTypes_InitializeSerializer_UnmanagedINetworkSerializable_MethodRef = method;
                         break;
-                    case nameof(NetworkVariableSerializationTypes.InitializeSerializer_UnmanagedINetworkSerializableArray):
+                    case nameof(NetworkVariableSerializationTypedInitializers.InitializeSerializer_UnmanagedINetworkSerializableArray):
                         m_NetworkVariableSerializationTypes_InitializeSerializer_UnmanagedINetworkSerializableArray_MethodRef = method;
                         break;
 
 #if UNITY_NETCODE_NATIVE_COLLECTION_SUPPORT
-                    case nameof(NetworkVariableSerializationTypes.InitializeSerializer_UnmanagedINetworkSerializableList):
+                    case nameof(NetworkVariableSerializationTypedInitializers.InitializeSerializer_UnmanagedINetworkSerializableList):
                         m_NetworkVariableSerializationTypes_InitializeSerializer_UnmanagedINetworkSerializableList_MethodRef = method;
                         break;
-                    case nameof(NetworkVariableSerializationTypes.InitializeSerializer_NativeHashSet):
+                    case nameof(NetworkVariableSerializationTypedInitializers.InitializeSerializer_NativeHashSet):
                         m_NetworkVariableSerializationTypes_InitializeSerializer_NativeHashSet_MethodRef = method;
                         break;
-                    case nameof(NetworkVariableSerializationTypes.InitializeSerializer_NativeHashMap):
+                    case nameof(NetworkVariableSerializationTypedInitializers.InitializeSerializer_NativeHashMap):
                         m_NetworkVariableSerializationTypes_InitializeSerializer_NativeHashMap_MethodRef = method;
                         break;
 #endif
-                    case nameof(NetworkVariableSerializationTypes.InitializeSerializer_List):
+                    case nameof(NetworkVariableSerializationTypedInitializers.InitializeSerializer_List):
                         m_NetworkVariableSerializationTypes_InitializeSerializer_List_MethodRef = method;
                         break;
-                    case nameof(NetworkVariableSerializationTypes.InitializeSerializer_HashSet):
+                    case nameof(NetworkVariableSerializationTypedInitializers.InitializeSerializer_HashSet):
                         m_NetworkVariableSerializationTypes_InitializeSerializer_HashSet_MethodRef = method;
                         break;
-                    case nameof(NetworkVariableSerializationTypes.InitializeSerializer_Dictionary):
+                    case nameof(NetworkVariableSerializationTypedInitializers.InitializeSerializer_Dictionary):
                         m_NetworkVariableSerializationTypes_InitializeSerializer_Dictionary_MethodRef = method;
                         break;
-                    case nameof(NetworkVariableSerializationTypes.InitializeSerializer_ManagedINetworkSerializable):
+                    case nameof(NetworkVariableSerializationTypedInitializers.InitializeSerializer_ManagedINetworkSerializable):
                         m_NetworkVariableSerializationTypes_InitializeSerializer_ManagedINetworkSerializable_MethodRef = method;
                         break;
-                    case nameof(NetworkVariableSerializationTypes.InitializeSerializer_FixedString):
+                    case nameof(NetworkVariableSerializationTypedInitializers.InitializeSerializer_FixedString):
                         m_NetworkVariableSerializationTypes_InitializeSerializer_FixedString_MethodRef = method;
                         break;
-                    case nameof(NetworkVariableSerializationTypes.InitializeSerializer_FixedStringArray):
+                    case nameof(NetworkVariableSerializationTypedInitializers.InitializeSerializer_FixedStringArray):
                         m_NetworkVariableSerializationTypes_InitializeSerializer_FixedStringArray_MethodRef = method;
                         break;
 
 #if UNITY_NETCODE_NATIVE_COLLECTION_SUPPORT
-                    case nameof(NetworkVariableSerializationTypes.InitializeSerializer_FixedStringList):
+                    case nameof(NetworkVariableSerializationTypedInitializers.InitializeSerializer_FixedStringList):
                         m_NetworkVariableSerializationTypes_InitializeSerializer_FixedStringList_MethodRef = method;
                         break;
 #endif
 
-                    case nameof(NetworkVariableSerializationTypes.InitializeEqualityChecker_ManagedIEquatable):
+                    case nameof(NetworkVariableSerializationTypedInitializers.InitializeEqualityChecker_ManagedIEquatable):
                         m_NetworkVariableSerializationTypes_InitializeEqualityChecker_ManagedIEquatable_MethodRef = method;
                         break;
-                    case nameof(NetworkVariableSerializationTypes.InitializeEqualityChecker_UnmanagedIEquatable):
+                    case nameof(NetworkVariableSerializationTypedInitializers.InitializeEqualityChecker_UnmanagedIEquatable):
                         m_NetworkVariableSerializationTypes_InitializeEqualityChecker_UnmanagedIEquatable_MethodRef = method;
                         break;
-                    case nameof(NetworkVariableSerializationTypes.InitializeEqualityChecker_UnmanagedIEquatableArray):
+                    case nameof(NetworkVariableSerializationTypedInitializers.InitializeEqualityChecker_UnmanagedIEquatableArray):
                         m_NetworkVariableSerializationTypes_InitializeEqualityChecker_UnmanagedIEquatableArray_MethodRef = method;
                         break;
 
 #if UNITY_NETCODE_NATIVE_COLLECTION_SUPPORT
-                    case nameof(NetworkVariableSerializationTypes.InitializeEqualityChecker_UnmanagedIEquatableList):
+                    case nameof(NetworkVariableSerializationTypedInitializers.InitializeEqualityChecker_UnmanagedIEquatableList):
                         m_NetworkVariableSerializationTypes_InitializeEqualityChecker_UnmanagedIEquatableList_MethodRef = method;
                         break;
-                    case nameof(NetworkVariableSerializationTypes.InitializeEqualityChecker_NativeHashSet):
+                    case nameof(NetworkVariableSerializationTypedInitializers.InitializeEqualityChecker_NativeHashSet):
                         m_NetworkVariableSerializationTypes_InitializeEqualityChecker_NativeHashSet_MethodRef = method;
                         break;
-                    case nameof(NetworkVariableSerializationTypes.InitializeEqualityChecker_NativeHashMap):
+                    case nameof(NetworkVariableSerializationTypedInitializers.InitializeEqualityChecker_NativeHashMap):
                         m_NetworkVariableSerializationTypes_InitializeEqualityChecker_NativeHashMap_MethodRef = method;
                         break;
 #endif
-                    case nameof(NetworkVariableSerializationTypes.InitializeEqualityChecker_List):
+                    case nameof(NetworkVariableSerializationTypedInitializers.InitializeEqualityChecker_List):
                         m_NetworkVariableSerializationTypes_InitializeEqualityChecker_List_MethodRef = method;
                         break;
-                    case nameof(NetworkVariableSerializationTypes.InitializeEqualityChecker_HashSet):
+                    case nameof(NetworkVariableSerializationTypedInitializers.InitializeEqualityChecker_HashSet):
                         m_NetworkVariableSerializationTypes_InitializeEqualityChecker_HashSet_MethodRef = method;
                         break;
-                    case nameof(NetworkVariableSerializationTypes.InitializeEqualityChecker_Dictionary):
+                    case nameof(NetworkVariableSerializationTypedInitializers.InitializeEqualityChecker_Dictionary):
                         m_NetworkVariableSerializationTypes_InitializeEqualityChecker_Dictionary_MethodRef = method;
                         break;
-                    case nameof(NetworkVariableSerializationTypes.InitializeEqualityChecker_UnmanagedValueEquals):
+                    case nameof(NetworkVariableSerializationTypedInitializers.InitializeEqualityChecker_UnmanagedValueEquals):
                         m_NetworkVariableSerializationTypes_InitializeEqualityChecker_UnmanagedValueEquals_MethodRef = method;
                         break;
-                    case nameof(NetworkVariableSerializationTypes.InitializeEqualityChecker_UnmanagedValueEqualsArray):
+                    case nameof(NetworkVariableSerializationTypedInitializers.InitializeEqualityChecker_UnmanagedValueEqualsArray):
                         m_NetworkVariableSerializationTypes_InitializeEqualityChecker_UnmanagedValueEqualsArray_MethodRef = method;
                         break;
 #if UNITY_NETCODE_NATIVE_COLLECTION_SUPPORT
-                    case nameof(NetworkVariableSerializationTypes.InitializeEqualityChecker_UnmanagedValueEqualsList):
+                    case nameof(NetworkVariableSerializationTypedInitializers.InitializeEqualityChecker_UnmanagedValueEqualsList):
                         m_NetworkVariableSerializationTypes_InitializeEqualityChecker_UnmanagedValueEqualsList_MethodRef = method;
                         break;
 #endif
-                    case nameof(NetworkVariableSerializationTypes.InitializeEqualityChecker_ManagedClassEquals):
+                    case nameof(NetworkVariableSerializationTypedInitializers.InitializeEqualityChecker_ManagedClassEquals):
                         m_NetworkVariableSerializationTypes_InitializeEqualityChecker_ManagedClassEquals_MethodRef = method;
                         break;
                 }

Editor/NetworkManagerEditor.cs

@@ -30,7 +30,7 @@ namespace Unity.Netcode.Editor
         private SerializedProperty m_ProtocolVersionProperty;
         private SerializedProperty m_NetworkTransportProperty;
         private SerializedProperty m_TickRateProperty;
-#if MULTIPLAYER_SDK_INSTALLED
+#if MULTIPLAYER_SERVICES_SDK_INSTALLED
         private SerializedProperty m_NetworkTopologyProperty;
 #endif
         private SerializedProperty m_ClientConnectionBufferTimeoutProperty;
@@ -102,7 +102,7 @@ namespace Unity.Netcode.Editor
             m_ProtocolVersionProperty = m_NetworkConfigProperty.FindPropertyRelative("ProtocolVersion");
             m_NetworkTransportProperty = m_NetworkConfigProperty.FindPropertyRelative("NetworkTransport");
             m_TickRateProperty = m_NetworkConfigProperty.FindPropertyRelative("TickRate");
-#if MULTIPLAYER_SDK_INSTALLED
+#if MULTIPLAYER_SERVICES_SDK_INSTALLED
             m_NetworkTopologyProperty = m_NetworkConfigProperty.FindPropertyRelative("NetworkTopology");
 #endif
             m_ClientConnectionBufferTimeoutProperty = m_NetworkConfigProperty.FindPropertyRelative("ClientConnectionBufferTimeout");
@@ -142,7 +142,7 @@ namespace Unity.Netcode.Editor
             m_ProtocolVersionProperty = m_NetworkConfigProperty.FindPropertyRelative("ProtocolVersion");
             m_NetworkTransportProperty = m_NetworkConfigProperty.FindPropertyRelative("NetworkTransport");
             m_TickRateProperty = m_NetworkConfigProperty.FindPropertyRelative("TickRate");
-#if MULTIPLAYER_SDK_INSTALLED
+#if MULTIPLAYER_SERVICES_SDK_INSTALLED
             m_NetworkTopologyProperty = m_NetworkConfigProperty.FindPropertyRelative("NetworkTopology");
 #endif
             m_ClientConnectionBufferTimeoutProperty = m_NetworkConfigProperty.FindPropertyRelative("ClientConnectionBufferTimeout");
@@ -186,7 +186,7 @@ namespace Unity.Netcode.Editor
 
                 EditorGUILayout.Space();
                 EditorGUILayout.LabelField("Network Settings", EditorStyles.boldLabel);
-#if MULTIPLAYER_SDK_INSTALLED
+#if MULTIPLAYER_SERVICES_SDK_INSTALLED
                 EditorGUILayout.PropertyField(m_NetworkTopologyProperty);
 #endif
                 EditorGUILayout.PropertyField(m_ProtocolVersionProperty);
@@ -310,20 +310,31 @@ namespace Unity.Netcode.Editor
                         GUI.enabled = false;
                     }
 
-                    if (GUILayout.Button(new GUIContent("Start Host", "Starts a host instance" + buttonDisabledReasonSuffix)))
+                    if (m_NetworkManager.NetworkConfig.NetworkTopology == NetworkTopologyTypes.ClientServer)
                     {
-                        m_NetworkManager.StartHost();
+                        if (GUILayout.Button(new GUIContent("Start Host", "Starts a host instance" + buttonDisabledReasonSuffix)))
+                        {
+                            m_NetworkManager.StartHost();
+                        }
+
+                        if (GUILayout.Button(new GUIContent("Start Server", "Starts a server instance" + buttonDisabledReasonSuffix)))
+                        {
+                            m_NetworkManager.StartServer();
+                        }
+
+                        if (GUILayout.Button(new GUIContent("Start Client", "Starts a client instance" + buttonDisabledReasonSuffix)))
+                        {
+                            m_NetworkManager.StartClient();
+                        }
+                    }
+                    else
+                    {
+                        if (GUILayout.Button(new GUIContent("Start Client", "Starts a distributed authority client instance" + buttonDisabledReasonSuffix)))
+                        {
+                            m_NetworkManager.StartClient();
+                        }
                     }
 
-                    if (GUILayout.Button(new GUIContent("Start Server", "Starts a server instance" + buttonDisabledReasonSuffix)))
-                    {
-                        m_NetworkManager.StartServer();
-                    }
-
-                    if (GUILayout.Button(new GUIContent("Start Client", "Starts a client instance" + buttonDisabledReasonSuffix)))
-                    {
-                        m_NetworkManager.StartClient();
-                    }
 
                     if (!EditorApplication.isPlaying)
                     {

Editor/NetworkObjectEditor.cs

@@ -1,5 +1,5 @@
 using System.Collections.Generic;
-#if MULTIPLAYER_SDK_INSTALLED
+#if BYPASS_DEFAULT_ENUM_DRAWER && MULTIPLAYER_SERVICES_SDK_INSTALLED
 using System.Linq;
 #endif
 using UnityEditor;
@@ -148,7 +148,7 @@ namespace Unity.Netcode.Editor
 
     // Keeping this here just in case, but it appears that in Unity 6 the visual bugs with
     // enum flags is resolved
-#if BYPASS_DEFAULT_ENUM_DRAWER && MULTIPLAYER_SDK_INSTALLED
+#if BYPASS_DEFAULT_ENUM_DRAWER && MULTIPLAYER_SERVICES_SDK_INSTALLED
     [CustomPropertyDrawer(typeof(NetworkObject.OwnershipStatus))]
     public class NetworkObjectOwnership : PropertyDrawer
     {

Editor/NetworkTransformEditor.cs

@@ -30,6 +30,7 @@ namespace Unity.Netcode.Editor
         private SerializedProperty m_UseQuaternionCompression;
         private SerializedProperty m_UseHalfFloatPrecision;
         private SerializedProperty m_SlerpPosition;
+        private SerializedProperty m_AuthorityMode;
 
         private static int s_ToggleOffset = 45;
         private static float s_MaxRowWidth = EditorGUIUtility.labelWidth + EditorGUIUtility.fieldWidth + 5;
@@ -38,7 +39,7 @@ namespace Unity.Netcode.Editor
         private static GUIContent s_ScaleLabel = EditorGUIUtility.TrTextContent("Scale");
 
         /// <inheritdoc/>
-        public void OnEnable()
+        public virtual void OnEnable()
         {
             m_UseUnreliableDeltas = serializedObject.FindProperty(nameof(NetworkTransform.UseUnreliableDeltas));
             m_SyncPositionXProperty = serializedObject.FindProperty(nameof(NetworkTransform.SyncPositionX));
@@ -59,12 +60,13 @@ namespace Unity.Netcode.Editor
             m_UseQuaternionCompression = serializedObject.FindProperty(nameof(NetworkTransform.UseQuaternionCompression));
             m_UseHalfFloatPrecision = serializedObject.FindProperty(nameof(NetworkTransform.UseHalfFloatPrecision));
             m_SlerpPosition = serializedObject.FindProperty(nameof(NetworkTransform.SlerpPosition));
+            m_AuthorityMode = serializedObject.FindProperty(nameof(NetworkTransform.AuthorityMode));
         }
 
         /// <inheritdoc/>
         public override void OnInspectorGUI()
         {
-            EditorGUILayout.LabelField("Syncing", EditorStyles.boldLabel);
+            EditorGUILayout.LabelField("Axis to Synchronize", EditorStyles.boldLabel);
             {
                 GUILayout.BeginHorizontal();
 
@@ -126,6 +128,11 @@ namespace Unity.Netcode.Editor
                 GUILayout.EndHorizontal();
             }
 
+            EditorGUILayout.Space();
+            EditorGUILayout.LabelField("Authority", EditorStyles.boldLabel);
+            {
+                EditorGUILayout.PropertyField(m_AuthorityMode);
+            }
             EditorGUILayout.Space();
             EditorGUILayout.LabelField("Thresholds", EditorStyles.boldLabel);
             EditorGUILayout.PropertyField(m_PositionThresholdProperty);

Editor/com.unity.netcode.editor.asmdef

@@ -57,7 +57,7 @@
         {
             "name": "com.unity.services.multiplayer",
             "expression": "0.2.0",
-            "define": "MULTIPLAYER_SDK_INSTALLED"
+            "define": "MULTIPLAYER_SERVICES_SDK_INSTALLED"
         }
     ],
     "noEngineReferences": false

Runtime/Components/NetworkRigidBodyBase.cs

@@ -45,6 +45,9 @@ namespace Unity.Netcode.Components
         private Rigidbody m_Rigidbody;
         private Rigidbody2D m_Rigidbody2D;
         internal NetworkTransform NetworkTransform;
+        private float m_TickFrequency;
+        private float m_TickRate;
+
         private enum InterpolationTypes
         {
             None,
@@ -120,6 +123,129 @@ namespace Unity.Netcode.Components
             }
         }
 
+        internal Vector3 GetAdjustedPositionThreshold()
+        {
+            // Since the threshold is a measurement of unity world space units per tick, we will allow for the maximum threshold
+            // to be no greater than the threshold measured in unity world space units per second
+            var thresholdMax = NetworkTransform.PositionThreshold * m_TickRate;
+            // Get the velocity in unity world space units per tick
+            var perTickVelocity = GetLinearVelocity() * m_TickFrequency;
+            // Since a rigid body can have "micro-motion" when allowed to come to rest (based on friction etc), we will allow for
+            // no less than 1/10th the threshold value.
+            var minThreshold = NetworkTransform.PositionThreshold * 0.1f;
+
+            // Finally, we adjust the threshold based on the body's current velocity
+            perTickVelocity.x = Mathf.Clamp(Mathf.Abs(perTickVelocity.x), minThreshold, thresholdMax);
+            perTickVelocity.y = Mathf.Clamp(Mathf.Abs(perTickVelocity.y), minThreshold, thresholdMax);
+            // 2D Rigidbody only moves on x & y axis
+            if (!m_IsRigidbody2D)
+            {
+                perTickVelocity.z = Mathf.Clamp(Mathf.Abs(perTickVelocity.z), minThreshold, thresholdMax);
+            }
+
+            return perTickVelocity;
+        }
+
+        internal Vector3 GetAdjustedRotationThreshold()
+        {
+            // Since the rotation threshold is a measurement pf degrees per tick, we get the maximum threshold
+            // by calculating the threshold in degrees per second.
+            var thresholdMax = NetworkTransform.RotAngleThreshold * m_TickRate;
+            // Angular velocity is expressed in radians per second where as the rotation being checked is in degrees.
+            // Convert the angular velocity to degrees per second and then convert that to degrees per tick.
+            var rotationPerTick = (GetAngularVelocity() * Mathf.Rad2Deg) * m_TickFrequency;
+            var minThreshold = NetworkTransform.RotAngleThreshold * m_TickFrequency;
+
+            // 2D Rigidbody only rotates around Z axis
+            if (!m_IsRigidbody2D)
+            {
+                rotationPerTick.x = Mathf.Clamp(Mathf.Abs(rotationPerTick.x), minThreshold, thresholdMax);
+                rotationPerTick.y = Mathf.Clamp(Mathf.Abs(rotationPerTick.y), minThreshold, thresholdMax);
+            }
+            rotationPerTick.z = Mathf.Clamp(Mathf.Abs(rotationPerTick.z), minThreshold, thresholdMax);
+
+            return rotationPerTick;
+        }
+
+        /// <summary>
+        /// Sets the linear velocity of the Rigidbody.
+        /// </summary>
+        /// <remarks>
+        /// For <see cref="Rigidbody2D"/>, only the x and y components of the <see cref="Vector3"/> are applied.
+        /// </remarks>        
+        public void SetLinearVelocity(Vector3 linearVelocity)
+        {
+            if (m_IsRigidbody2D)
+            {
+                m_Rigidbody2D.velocity = linearVelocity;
+            }
+            else
+            {
+                m_Rigidbody.linearVelocity = linearVelocity;
+            }
+        }
+
+        /// <summary>
+        /// Gets the linear velocity of the Rigidbody.
+        /// </summary>
+        /// <remarks>
+        /// For <see cref="Rigidbody2D"/>, the <see cref="Vector3"/> velocity returned is only applied to the x and y components.
+        /// </remarks>
+        /// <returns><see cref="Vector3"/> as the linear velocity</returns>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public Vector3 GetLinearVelocity()
+        {
+            if (m_IsRigidbody2D)
+            {
+                return m_Rigidbody2D.velocity;
+            }
+            else
+            {
+                return m_Rigidbody.linearVelocity;
+            }
+        }
+
+        /// <summary>
+        /// Sets the angular velocity for the Rigidbody.
+        /// </summary>
+        /// <remarks>
+        /// For <see cref="Rigidbody2D"/>, the z component of <param name="angularVelocity"/> is only used to set the angular velocity.
+        /// A quick way to pass in a 2D angular velocity component is: <see cref="Vector3.forward"/> * angularVelocity (where angularVelocity is a float)
+        /// </remarks>
+        /// <param name="angularVelocity">the angular velocity to apply to the body</param>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public void SetAngularVelocity(Vector3 angularVelocity)
+        {
+            if (m_IsRigidbody2D)
+            {
+                m_Rigidbody2D.angularVelocity = angularVelocity.z;
+            }
+            else
+            {
+                m_Rigidbody.angularVelocity = angularVelocity;
+            }
+        }
+
+        /// <summary>
+        /// Gets the angular velocity for the Rigidbody.
+        /// </summary>
+        /// <remarks>
+        /// For <see cref="Rigidbody2D"/>, the z component of the <see cref="Vector3"/> returned is the angular velocity of the object.
+        /// </remarks>
+        /// <returns>angular velocity as a <see cref="Vector3"/></returns>
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public Vector3 GetAngularVelocity()
+        {
+            if (m_IsRigidbody2D)
+            {
+                return Vector3.forward * m_Rigidbody2D.velocity;
+            }
+            else
+            {
+                return m_Rigidbody.angularVelocity;
+            }
+        }
+
         /// <summary>
         /// Gets the position of the Rigidbody
         /// </summary>
@@ -210,6 +336,9 @@ namespace Unity.Netcode.Components
             }
         }
 
+        // Used for Rigidbody only (see info on normalized below)
+        private Vector4 m_QuaternionCheck = Vector4.zero;
+
         /// <summary>
         /// Rotatates the Rigidbody towards a specified rotation
         /// </summary>
@@ -227,6 +356,17 @@ namespace Unity.Netcode.Components
             }
             else
             {
+                // Evidently we need to check to make sure the quaternion is a perfect
+                // magnitude of 1.0f when applying the rotation to a rigid body.
+                m_QuaternionCheck.x = rotation.x;
+                m_QuaternionCheck.y = rotation.y;
+                m_QuaternionCheck.z = rotation.z;
+                m_QuaternionCheck.w = rotation.w;
+                // If the magnitude is greater than 1.0f (even by a very small fractional value), then normalize the quaternion
+                if (m_QuaternionCheck.magnitude != 1.0f)
+                {
+                    rotation.Normalize();
+                }
                 m_Rigidbody.MoveRotation(rotation);
             }
         }
@@ -501,6 +641,8 @@ namespace Unity.Netcode.Components
         /// <inheritdoc />
         public override void OnNetworkSpawn()
         {
+            m_TickFrequency = 1.0f / NetworkManager.NetworkConfig.TickRate;
+            m_TickRate = NetworkManager.NetworkConfig.TickRate;
             UpdateOwnershipAuthority();
         }
 

Runtime/Components/NetworkTransform.cs

@@ -920,6 +920,22 @@ namespace Unity.Netcode.Components
         #endregion
 
         #region PROPERTIES AND GENERAL METHODS
+
+
+        public enum AuthorityModes
+        {
+            Server,
+            Owner,
+        }
+#if MULTIPLAYER_SERVICES_SDK_INSTALLED
+        [Tooltip("Selects who has authority (sends state updates) over the transform. When the network topology is set to distributed authority, this always defaults to owner authority. If server (the default), then only server-side adjustments to the " +
+            "transform will be synchronized with clients. If owner (or client), then only the owner-side adjustments to the transform will be synchronized with both the server and other clients.")]
+#else
+        [Tooltip("Selects who has authority (sends state updates) over the transform. If server (the default), then only server-side adjustments to the transform will be synchronized with clients. If owner (or client), " +
+            "then only the owner-side adjustments to the transform will be synchronized with both the server and other clients.")]
+#endif
+        public AuthorityModes AuthorityMode;
+
         /// <summary>
         /// The default position change threshold value.
         /// Any changes above this threshold will be replicated.
@@ -1487,7 +1503,7 @@ namespace Unity.Netcode.Components
         /// </remarks>
         /// <param name="transformToCommit">the transform to be committed</param>
         /// <param name="dirtyTime">time it was marked dirty</param>
-        protected void TryCommitTransformToServer(Transform transformToCommit, double dirtyTime)
+        internal void TryCommitTransformToServer(Transform transformToCommit, double dirtyTime)
         {
             if (!IsSpawned)
             {
@@ -1568,8 +1584,6 @@ namespace Unity.Netcode.Components
             // If the transform has deltas (returns dirty) or if an explicitly set state is pending
             if (m_LocalAuthoritativeNetworkState.ExplicitSet || CheckForStateChange(ref m_LocalAuthoritativeNetworkState, ref transformToCommit, synchronize))
             {
-                m_LocalAuthoritativeNetworkState.LastSerializedSize = m_OldState.LastSerializedSize;
-
                 // If the state was explicitly set, then update the network tick to match the locally calculate tick
                 if (m_LocalAuthoritativeNetworkState.ExplicitSet)
                 {
@@ -1699,9 +1713,20 @@ namespace Unity.Netcode.Components
 #if COM_UNITY_MODULES_PHYSICS
             var position = m_UseRigidbodyForMotion ? m_NetworkRigidbodyInternal.GetPosition() : InLocalSpace ? transformToUse.localPosition : transformToUse.position;
             var rotation = m_UseRigidbodyForMotion ? m_NetworkRigidbodyInternal.GetRotation() : InLocalSpace ? transformToUse.localRotation : transformToUse.rotation;
+
+            var positionThreshold = Vector3.one * PositionThreshold;
+            var rotationThreshold = Vector3.one * RotAngleThreshold;
+
+            if (m_UseRigidbodyForMotion)
+            {
+                positionThreshold = m_NetworkRigidbodyInternal.GetAdjustedPositionThreshold();
+                rotationThreshold = m_NetworkRigidbodyInternal.GetAdjustedRotationThreshold();
+            }
 #else
             var position = InLocalSpace ? transformToUse.localPosition : transformToUse.position;
             var rotation = InLocalSpace ? transformToUse.localRotation : transformToUse.rotation;
+            var positionThreshold =  Vector3.one * PositionThreshold;
+            var rotationThreshold = Vector3.one * RotAngleThreshold;
 #endif
             var rotAngles = rotation.eulerAngles;
             var scale = transformToUse.localScale;
@@ -1828,21 +1853,21 @@ namespace Unity.Netcode.Components
             // Begin delta checks against last sent state update
             if (!UseHalfFloatPrecision)
             {
-                if (SyncPositionX && (Mathf.Abs(networkState.PositionX - position.x) >= PositionThreshold || networkState.IsTeleportingNextFrame || isAxisSync))
+                if (SyncPositionX && (Mathf.Abs(networkState.PositionX - position.x) >= positionThreshold.x || networkState.IsTeleportingNextFrame || isAxisSync))
                 {
                     networkState.PositionX = position.x;
                     networkState.HasPositionX = true;
                     isPositionDirty = true;
                 }
 
-                if (SyncPositionY && (Mathf.Abs(networkState.PositionY - position.y) >= PositionThreshold || networkState.IsTeleportingNextFrame || isAxisSync))
+                if (SyncPositionY && (Mathf.Abs(networkState.PositionY - position.y) >= positionThreshold.y || networkState.IsTeleportingNextFrame || isAxisSync))
                 {
                     networkState.PositionY = position.y;
                     networkState.HasPositionY = true;
                     isPositionDirty = true;
                 }
 
-                if (SyncPositionZ && (Mathf.Abs(networkState.PositionZ - position.z) >= PositionThreshold || networkState.IsTeleportingNextFrame || isAxisSync))
+                if (SyncPositionZ && (Mathf.Abs(networkState.PositionZ - position.z) >= positionThreshold.z || networkState.IsTeleportingNextFrame || isAxisSync))
                 {
                     networkState.PositionZ = position.z;
                     networkState.HasPositionZ = true;
@@ -1863,7 +1888,7 @@ namespace Unity.Netcode.Components
                 {
                     for (int i = 0; i < 3; i++)
                     {
-                        if (Math.Abs(position[i] - m_HalfPositionState.PreviousPosition[i]) >= PositionThreshold)
+                        if (Math.Abs(position[i] - m_HalfPositionState.PreviousPosition[i]) >= positionThreshold[i])
                         {
                             isPositionDirty = i == 0 ? SyncPositionX : i == 1 ? SyncPositionY : SyncPositionZ;
                             if (!isPositionDirty)
@@ -1958,21 +1983,21 @@ namespace Unity.Netcode.Components
 
             if (!UseQuaternionSynchronization)
             {
-                if (SyncRotAngleX && (Mathf.Abs(Mathf.DeltaAngle(networkState.RotAngleX, rotAngles.x)) >= RotAngleThreshold || networkState.IsTeleportingNextFrame || isAxisSync))
+                if (SyncRotAngleX && (Mathf.Abs(Mathf.DeltaAngle(networkState.RotAngleX, rotAngles.x)) >= rotationThreshold.x || networkState.IsTeleportingNextFrame || isAxisSync))
                 {
                     networkState.RotAngleX = rotAngles.x;
                     networkState.HasRotAngleX = true;
                     isRotationDirty = true;
                 }
 
-                if (SyncRotAngleY && (Mathf.Abs(Mathf.DeltaAngle(networkState.RotAngleY, rotAngles.y)) >= RotAngleThreshold || networkState.IsTeleportingNextFrame || isAxisSync))
+                if (SyncRotAngleY && (Mathf.Abs(Mathf.DeltaAngle(networkState.RotAngleY, rotAngles.y)) >= rotationThreshold.y || networkState.IsTeleportingNextFrame || isAxisSync))
                 {
                     networkState.RotAngleY = rotAngles.y;
                     networkState.HasRotAngleY = true;
                     isRotationDirty = true;
                 }
 
-                if (SyncRotAngleZ && (Mathf.Abs(Mathf.DeltaAngle(networkState.RotAngleZ, rotAngles.z)) >= RotAngleThreshold || networkState.IsTeleportingNextFrame || isAxisSync))
+                if (SyncRotAngleZ && (Mathf.Abs(Mathf.DeltaAngle(networkState.RotAngleZ, rotAngles.z)) >= rotationThreshold.z || networkState.IsTeleportingNextFrame || isAxisSync))
                 {
                     networkState.RotAngleZ = rotAngles.z;
                     networkState.HasRotAngleZ = true;
@@ -1989,7 +2014,7 @@ namespace Unity.Netcode.Components
                     var previousRotation = networkState.Rotation.eulerAngles;
                     for (int i = 0; i < 3; i++)
                     {
-                        if (Mathf.Abs(Mathf.DeltaAngle(previousRotation[i], rotAngles[i])) >= RotAngleThreshold)
+                        if (Mathf.Abs(Mathf.DeltaAngle(previousRotation[i], rotAngles[i])) >= rotationThreshold[i])
                         {
                             isRotationDirty = true;
                             break;
@@ -2984,7 +3009,13 @@ namespace Unity.Netcode.Components
                 return;
             }
             m_CachedNetworkObject = NetworkObject;
+            if (m_CachedNetworkManager && m_CachedNetworkManager.DistributedAuthorityMode)
+            {
+                AuthorityMode = AuthorityModes.Owner;
+            }
             CanCommitToTransform = IsServerAuthoritative() ? IsServer : IsOwner;
+
+
             var currentPosition = GetSpaceRelativePosition();
             var currentRotation = GetSpaceRelativeRotation();
 
@@ -3011,22 +3042,24 @@ namespace Unity.Netcode.Components
 #else
             var forUpdate = true;
 #endif
+            m_LocalAuthoritativeNetworkState.SynchronizeBaseHalfFloat = false;
 
             if (CanCommitToTransform)
             {
-
                 // Make sure authority doesn't get added to updates (no need to do this on the authority side)
                 m_CachedNetworkManager.NetworkTransformRegistration(this, forUpdate, false);
                 if (UseHalfFloatPrecision)
                 {
                     m_HalfPositionState = new NetworkDeltaPosition(currentPosition, m_CachedNetworkManager.ServerTime.Tick, math.bool3(SyncPositionX, SyncPositionY, SyncPositionZ));
+                    m_LocalAuthoritativeNetworkState.SynchronizeBaseHalfFloat = isOwnershipChange;
+                    SetState(teleportDisabled: false);
                 }
+
                 m_CurrentPosition = currentPosition;
                 m_TargetPosition = currentPosition;
 
                 RegisterForTickUpdate(this);
 
-                m_LocalAuthoritativeNetworkState.SynchronizeBaseHalfFloat = false;
                 if (UseHalfFloatPrecision && isOwnershipChange && !IsServerAuthoritative() && Interpolate)
                 {
                     m_HalfFloatTargetTickOwnership = m_CachedNetworkManager.ServerTime.Tick;
@@ -3038,16 +3071,13 @@ namespace Unity.Netcode.Components
                 m_CachedNetworkManager.NetworkTransformRegistration(this, forUpdate, true);
                 // Remove this instance from the tick update
                 DeregisterForTickUpdate(this);
-
                 ResetInterpolatedStateToCurrentAuthoritativeState();
-                m_LocalAuthoritativeNetworkState.SynchronizeBaseHalfFloat = false;
                 m_CurrentPosition = currentPosition;
                 m_TargetPosition = currentPosition;
                 m_CurrentScale = transform.localScale;
                 m_TargetScale = transform.localScale;
                 m_CurrentRotation = currentRotation;
                 m_TargetRotation = currentRotation.eulerAngles;
-
             }
             OnInitialize(ref m_LocalAuthoritativeNetworkState);
         }
@@ -3296,7 +3326,7 @@ namespace Unity.Netcode.Components
             {
                 var serverTime = m_CachedNetworkManager.ServerTime;
                 var cachedServerTime = serverTime.Time;
-                var offset = (float)serverTime.TickOffset;
+                //var offset = (float)serverTime.TickOffset;
 #if COM_UNITY_MODULES_PHYSICS
                 var cachedDeltaTime = m_UseRigidbodyForMotion ? m_CachedNetworkManager.RealTimeProvider.FixedDeltaTime : m_CachedNetworkManager.RealTimeProvider.DeltaTime;
 #else
@@ -3314,7 +3344,7 @@ namespace Unity.Netcode.Components
                 //offset = m_NetworkTransformTickRegistration.Offset;
                 //}
 
-                var cachedRenderTime = serverTime.TimeTicksAgo(ticksAgo, offset).Time;
+                var cachedRenderTime = serverTime.TimeTicksAgo(ticksAgo).Time;
 
                 // Now only update the interpolators for the portions of the transform being synchronized
                 if (SynchronizePosition)
@@ -3388,28 +3418,32 @@ namespace Unity.Netcode.Components
 #endif
 
         /// <summary>
-        /// Override this method and return false to switch to owner authoritative mode
+        /// Determines whether the <see cref="NetworkTransform"/> is <see cref="AuthorityModes.Server"/> or <see cref="AuthorityModes.Owner"/> based on the <see cref="AuthorityMode"/> property.
+        /// You can override this method to control this logic. 
         /// </summary>
-        /// <returns>(<see cref="true"/> or <see cref="false"/>) where when false it runs as owner-client authoritative</returns>
+        /// <returns><see cref="true"/> or <see cref="false"/></returns>
         protected virtual bool OnIsServerAuthoritative()
         {
-            if (m_CachedNetworkManager)
-            {
-                return !m_CachedNetworkManager.DistributedAuthorityMode;
-            }
-            return true;
+            return AuthorityMode == AuthorityModes.Server;
         }
 
         /// <summary>
         /// Method to determine if this <see cref="NetworkTransform"/> instance is owner or server authoritative.
         /// </summary>
         /// <remarks>
-        /// Used by <see cref="NetworkRigidbody"/> to determines if this is server or owner authoritative.
+        /// When using a <see cref="NetworkTopologyTypes.DistributedAuthority"/> <see cref="NetworkConfig.NetworkTopology"/>, this will always be viewed as a <see cref="AuthorityModes.Owner"/> authoritative motion model.
         /// </remarks>
         /// <returns><see cref="true"/> or <see cref="false"/></returns>
         public bool IsServerAuthoritative()
         {
-            return OnIsServerAuthoritative();
+            if (m_CachedNetworkManager && m_CachedNetworkManager.DistributedAuthorityMode)
+            {
+                return false;
+            }
+            else
+            {
+                return OnIsServerAuthoritative();
+            }
         }
 
         #endregion
@@ -3451,9 +3485,10 @@ namespace Unity.Netcode.Components
         private NetworkTransformMessage m_OutboundMessage = new NetworkTransformMessage();
 
 
-        internal void SerializeMessage(FastBufferWriter writer, int targetVersion)
+        internal int SerializeMessage(FastBufferWriter writer, int targetVersion)
         {
             var networkObject = NetworkObject;
+            var position = writer.Position;
             BytePacker.WriteValueBitPacked(writer, NetworkObjectId);
             BytePacker.WriteValueBitPacked(writer, (int)NetworkBehaviourId);
             writer.WriteNetworkSerializable(m_LocalAuthoritativeNetworkState);
@@ -3470,6 +3505,7 @@ namespace Unity.Netcode.Components
                     BytePacker.WriteValuePacked(writer, targetId);
                 }
             }
+            return writer.Position - position;
         }
 
         /// <summary>
@@ -3482,7 +3518,7 @@ namespace Unity.Netcode.Components
                 return;
             }
 
-            bool isServerAuthoritative = OnIsServerAuthoritative();
+            bool isServerAuthoritative = IsServerAuthoritative();
             if (isServerAuthoritative && !IsServer)
             {
                 Debug.LogError($"Server authoritative {nameof(NetworkTransform)} can only be updated by the server!");
@@ -3526,6 +3562,7 @@ namespace Unity.Netcode.Components
                 // Clients (owner authoritative) send messages to the server-host
                 NetworkManager.MessageManager.SendMessage(ref m_OutboundMessage, networkDelivery, NetworkManager.ServerClientId);
             }
+            m_LocalAuthoritativeNetworkState.LastSerializedSize = m_OutboundMessage.BytesWritten;
         }
         #endregion
 

Runtime/Connection/NetworkClient.cs

@@ -1,15 +1,8 @@
-using System.Collections.Generic;
 using UnityEngine;
 
 namespace Unity.Netcode
 {
 
-    public enum NetworkTopologyTypes
-    {
-        ClientServer,
-        DistributedAuthority
-    }
-
     /// <summary>
     /// A NetworkClient
     /// </summary>
@@ -61,9 +54,9 @@ namespace Unity.Netcode
         public NetworkObject PlayerObject;
 
         /// <summary>
-        /// The list of NetworkObject's owned by this client instance
+        /// The NetworkObject's owned by this client instance
         /// </summary>
-        public List<NetworkObject> OwnedObjects => IsConnected ? SpawnManager.GetClientOwnedObjects(ClientId) : new List<NetworkObject>();
+        public NetworkObject[] OwnedObjects => IsConnected ? SpawnManager.GetClientOwnedObjects(ClientId) : new NetworkObject[] { };
 
         internal NetworkSpawnManager SpawnManager { get; private set; }
 

Runtime/Connection/NetworkConnectionManager.cs

@@ -1229,6 +1229,8 @@ namespace Unity.Netcode
                 var message = new ClientDisconnectedMessage { ClientId = clientId };
                 MessageManager?.SendMessage(ref message, NetworkDelivery.ReliableFragmentedSequenced, ConnectedClientIds);
 
+                // Used for testing/validation purposes only
+#if ENABLE_DAHOST_AUTOPROMOTE_SESSION_OWNER
                 if (NetworkManager.DistributedAuthorityMode && !NetworkManager.ShutdownInProgress && NetworkManager.IsListening)
                 {
                     var newSessionOwner = NetworkManager.LocalClientId;
@@ -1259,6 +1261,7 @@ namespace Unity.Netcode
                     MessageManager?.SendMessage(ref sessionOwnerMessage, NetworkDelivery.ReliableFragmentedSequenced, ConnectedClientIds);
                     NetworkManager.SetSessionOwner(newSessionOwner);
                 }
+#endif
             }
 
             // If the client ID transport map exists

Runtime/Core/NetworkManager.cs

@@ -36,17 +36,13 @@ namespace Unity.Netcode
 
 #pragma warning restore IDE1006 // restore naming rule violation check
 
+        internal static bool IsDistributedAuthority;
+
         /// <summary>
         /// Distributed Authority Mode
         /// Returns true if the current session is running in distributed authority mode.
         /// </summary>
-        public bool DistributedAuthorityMode
-        {
-            get
-            {
-                return NetworkConfig.NetworkTopology == NetworkTopologyTypes.DistributedAuthority;
-            }
-        }
+        public bool DistributedAuthorityMode { get; private set; }
 
         /// <summary>
         /// Distributed Authority Mode
@@ -131,6 +127,18 @@ namespace Unity.Netcode
 
         public ulong CurrentSessionOwner { get; internal set; }
 
+        /// <summary>
+        /// Delegate declaration for <see cref="OnSessionOwnerPromoted"/>
+        /// </summary>
+        /// <param name="sessionOwnerPromoted">the new session owner client identifier</param>
+        public delegate void OnSessionOwnerPromotedDelegateHandler(ulong sessionOwnerPromoted);
+
+        /// <summary>
+        /// Network Topology: Distributed Authority
+        /// When a new session owner is promoted, this event is triggered on all connected clients
+        /// </summary>
+        public event OnSessionOwnerPromotedDelegateHandler OnSessionOwnerPromoted;
+
         internal void SetSessionOwner(ulong sessionOwner)
         {
             var previousSessionOwner = CurrentSessionOwner;
@@ -151,10 +159,12 @@ namespace Unity.Netcode
                     }
                 }
             }
+
+            OnSessionOwnerPromoted?.Invoke(sessionOwner);
         }
 
         // TODO: Make this internal after testing
-        public void PromoteSessionOwner(ulong clientId)
+        internal void PromoteSessionOwner(ulong clientId)
         {
             if (!DistributedAuthorityMode)
             {
@@ -217,12 +227,27 @@ namespace Unity.Netcode
 #endif
         }
 
+        private void UpdateTopology()
+        {
+            var transportTopology = IsListening ? NetworkConfig.NetworkTransport.CurrentTopology() : NetworkConfig.NetworkTopology;
+            if (transportTopology != NetworkConfig.NetworkTopology)
+            {
+                NetworkLog.LogErrorServer($"[Topology Mismatch] Transport detected an issue with the topology ({transportTopology} | {NetworkConfig.NetworkTopology}) usage or setting! Disconnecting from session.");
+                Shutdown();
+            }
+            else
+            {
+                IsDistributedAuthority = DistributedAuthorityMode = transportTopology == NetworkTopologyTypes.DistributedAuthority;
+            }
+        }
+
         public void NetworkUpdate(NetworkUpdateStage updateStage)
         {
             switch (updateStage)
             {
                 case NetworkUpdateStage.EarlyUpdate:
                     {
+                        UpdateTopology();
                         ConnectionManager.ProcessPendingApprovals();
                         ConnectionManager.PollAndHandleNetworkEvents();
 
@@ -1012,6 +1037,8 @@ namespace Unity.Netcode
 #endif
             NetworkTransformUpdate.Clear();
 
+            UpdateTopology();
+
             //DANGOEXP TODO: Remove this before finalizing the experimental release
             NetworkConfig.AutoSpawnPlayerPrefabClientSide = DistributedAuthorityMode;
 
@@ -1191,6 +1218,17 @@ namespace Unity.Netcode
                 {
                     SpawnManager.ServerSpawnSceneObjectsOnStartSweep();
 
+                    // Notify the server that all in-scnee placed NetworkObjects are spawned at this time.
+                    foreach (var networkObject in SpawnManager.SpawnedObjectsList)
+                    {
+                        networkObject.InternalInSceneNetworkObjectsSpawned();
+                    }
+
+                    // Notify the server that everything should be synchronized/spawned at this time.
+                    foreach (var networkObject in SpawnManager.SpawnedObjectsList)
+                    {
+                        networkObject.InternalNetworkSessionSynchronized();
+                    }
                     OnServerStarted?.Invoke();
                     ConnectionManager.LocalClient.IsApproved = true;
                     return true;
@@ -1337,6 +1375,17 @@ namespace Unity.Netcode
             }
 
             SpawnManager.ServerSpawnSceneObjectsOnStartSweep();
+            // Notify the host that all in-scnee placed NetworkObjects are spawned at this time.
+            foreach (var networkObject in SpawnManager.SpawnedObjectsList)
+            {
+                networkObject.InternalInSceneNetworkObjectsSpawned();
+            }
+
+            // Notify the host that everything should be synchronized/spawned at this time.
+            foreach (var networkObject in SpawnManager.SpawnedObjectsList)
+            {
+                networkObject.InternalNetworkSessionSynchronized();
+            }
 
             OnServerStarted?.Invoke();
             OnClientStarted?.Invoke();

Runtime/Core/NetworkObject.cs

@@ -430,7 +430,7 @@ namespace Unity.Netcode
         /// Determines whether a NetworkObject can be distributed to other clients during
         /// a <see cref="NetworkTopologyTypes.DistributedAuthority"/> session.
         /// </summary>
-#if !MULTIPLAYER_SDK_INSTALLED
+#if !MULTIPLAYER_SERVICES_SDK_INSTALLED
         [HideInInspector]
 #endif
         [SerializeField]

Runtime/Messaging/ILPPMessageProvider.cs

@@ -44,9 +44,9 @@ namespace Unity.Netcode
             SceneEvent = 17,
             ServerLog = 18,
             ServerRpc = 19,
-            TimeSync = 20,
-            Unnamed = 21,
-            SessionOwner = 22
+            SessionOwner = 20,
+            TimeSync = 21,
+            Unnamed = 22,
         }
 
 

Runtime/Messaging/Messages/ConnectionApprovedMessage.cs

@@ -243,6 +243,13 @@ namespace Unity.Netcode
                         // Spawn any in-scene placed NetworkObjects
                         networkManager.SpawnManager.ServerSpawnSceneObjectsOnStartSweep();
 
+                        // With scene management enabled and since the session owner doesn't send a Synchronize scene event synchronize itself,
+                        // we need to notify the session owner that all in-scnee placed NetworkObjects are spawned at this time.
+                        foreach (var networkObject in networkManager.SpawnManager.SpawnedObjectsList)
+                        {
+                            networkObject.InternalInSceneNetworkObjectsSpawned();
+                        }
+
                         // Spawn the local player of the session owner
                         if (networkManager.AutoSpawnPlayerPrefabClientSide)
                         {
@@ -251,6 +258,17 @@ namespace Unity.Netcode
 
                         // Synchronize the service with the initial session owner's loaded scenes and spawned objects
                         networkManager.SceneManager.SynchronizeNetworkObjects(NetworkManager.ServerClientId);
+
+                        // With scene management enabled and since the session owner doesn't send a Synchronize scene event synchronize itself,
+                        // we need to notify the session owner that everything should be synchronized/spawned at this time.
+                        foreach (var networkObject in networkManager.SpawnManager.SpawnedObjectsList)
+                        {
+                            networkObject.InternalNetworkSessionSynchronized();
+                        }
+
+                        // When scene management is enabled and since the session owner is synchronizing the service (i.e. acting like  host),
+                        // we need to locallyh invoke the OnClientConnected callback at this point in time.
+                        networkManager.ConnectionManager.InvokeOnClientConnectedCallback(OwnerClientId);
                     }
                 }
             }

Runtime/Messaging/Messages/NetworkTransformMessage.cs

@@ -17,6 +17,8 @@ namespace Unity.Netcode
         internal NetworkTransform.NetworkTransformState State;
         private FastBufferReader m_CurrentReader;
 
+        internal int BytesWritten;
+
         private unsafe void CopyPayload(ref FastBufferWriter writer)
         {
             writer.WriteBytesSafe(m_CurrentReader.GetUnsafePtrAtCurrentPosition(), m_CurrentReader.Length - m_CurrentReader.Position);
@@ -30,7 +32,7 @@ namespace Unity.Netcode
             }
             else
             {
-                NetworkTransform.SerializeMessage(writer, targetVersion);
+                BytesWritten = NetworkTransform.SerializeMessage(writer, targetVersion);
             }
         }
 
@@ -75,6 +77,7 @@ namespace Unity.Netcode
                 ownerAuthoritativeServerSide = !isServerAuthoritative && networkManager.IsServer;
 
                 reader.ReadNetworkSerializableInPlace(ref NetworkTransform.InboundState);
+                NetworkTransform.InboundState.LastSerializedSize = reader.Position - currentPosition;
             }
             else
             {

Runtime/Messaging/NetworkMessageManager.cs

@@ -34,6 +34,9 @@ namespace Unity.Netcode
     internal class NetworkMessageManager : IDisposable
     {
         public bool StopProcessing = false;
+        private static Type s_ConnectionApprovedType = typeof(ConnectionApprovedMessage);
+        private static Type s_ConnectionRequestType = typeof(ConnectionRequestMessage);
+        private static Type s_DisconnectReasonType = typeof(DisconnectReasonMessage);
 
         private struct ReceiveQueueItem
         {
@@ -524,6 +527,7 @@ namespace Unity.Netcode
             return new T().Version;
         }
 
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
         internal int GetMessageVersion(Type type, ulong clientId, bool forReceive = false)
         {
             if (!m_PerClientMessageVersions.TryGetValue(clientId, out var versionMap))
@@ -551,16 +555,20 @@ namespace Unity.Netcode
             return messageVersion;
         }
 
+
+
         public static void ReceiveMessage<T>(FastBufferReader reader, ref NetworkContext context, NetworkMessageManager manager) where T : INetworkMessage, new()
         {
+            var messageType = typeof(T);
             var message = new T();
             var messageVersion = 0;
+
             // Special cases because these are the messages that carry the version info - thus the version info isn't
             // populated yet when we get these. The first part of these messages always has to be the version data
             // and can't change.
-            if (typeof(T) != typeof(ConnectionRequestMessage) && typeof(T) != typeof(ConnectionApprovedMessage) && typeof(T) != typeof(DisconnectReasonMessage) && context.SenderId != manager.m_LocalClientId)
+            if (messageType != s_ConnectionRequestType && messageType != s_ConnectionApprovedType && messageType != s_DisconnectReasonType && context.SenderId != manager.m_LocalClientId)
             {
-                messageVersion = manager.GetMessageVersion(typeof(T), context.SenderId, true);
+                messageVersion = manager.GetMessageVersion(messageType, context.SenderId, true);
                 if (messageVersion < 0)
                 {
                     return;
@@ -612,7 +620,7 @@ namespace Unity.Netcode
                 var messageVersion = 0;
                 // Special case because this is the message that carries the version info - thus the version info isn't populated yet when we get this.
                 // The first part of this message always has to be the version data and can't change.
-                if (typeof(TMessageType) != typeof(ConnectionRequestMessage))
+                if (typeof(TMessageType) != s_ConnectionRequestType)
                 {
                     messageVersion = GetMessageVersion(typeof(TMessageType), clientIds[i]);
                     if (messageVersion < 0)
@@ -666,7 +674,7 @@ namespace Unity.Netcode
 
                 // Special case because this is the message that carries the version info - thus the version info isn't populated yet when we get this.
                 // The first part of this message always has to be the version data and can't change.
-                if (typeof(TMessageType) != typeof(ConnectionRequestMessage))
+                if (typeof(TMessageType) != s_ConnectionRequestType)
                 {
                     var messageVersion = GetMessageVersion(typeof(TMessageType), clientIds[i]);
                     if (messageVersion < 0)
@@ -746,7 +754,7 @@ namespace Unity.Netcode
             // Special case because this is the message that carries the version info - thus the version info isn't
             // populated yet when we get this. The first part of this message always has to be the version data
             // and can't change.
-            if (typeof(TMessageType) != typeof(ConnectionRequestMessage))
+            if (typeof(TMessageType) != s_ConnectionRequestType)
             {
                 messageVersion = GetMessageVersion(typeof(TMessageType), clientId);
                 if (messageVersion < 0)

Runtime/Messaging/RpcTargets/EveryoneRpcTarget.cs

@@ -4,23 +4,37 @@ namespace Unity.Netcode
     {
         private NotServerRpcTarget m_NotServerRpcTarget;
         private ServerRpcTarget m_ServerRpcTarget;
+        private NotAuthorityRpcTarget m_NotAuthorityRpcTarget;
+        private AuthorityRpcTarget m_AuthorityRpcTarget;
 
         public override void Dispose()
         {
             m_NotServerRpcTarget.Dispose();
             m_ServerRpcTarget.Dispose();
+            m_NotAuthorityRpcTarget.Dispose();
+            m_AuthorityRpcTarget.Dispose();
         }
 
         internal override void Send(NetworkBehaviour behaviour, ref RpcMessage message, NetworkDelivery delivery, RpcParams rpcParams)
         {
-            m_NotServerRpcTarget.Send(behaviour, ref message, delivery, rpcParams);
-            m_ServerRpcTarget.Send(behaviour, ref message, delivery, rpcParams);
+            if (NetworkManager.IsDistributedAuthority)
+            {
+                m_NotAuthorityRpcTarget.Send(behaviour, ref message, delivery, rpcParams);
+                m_AuthorityRpcTarget.Send(behaviour, ref message, delivery, rpcParams);
+            }
+            else
+            {
+                m_NotServerRpcTarget.Send(behaviour, ref message, delivery, rpcParams);
+                m_ServerRpcTarget.Send(behaviour, ref message, delivery, rpcParams);
+            }
         }
 
         internal EveryoneRpcTarget(NetworkManager manager) : base(manager)
         {
             m_NotServerRpcTarget = new NotServerRpcTarget(manager);
             m_ServerRpcTarget = new ServerRpcTarget(manager);
+            m_NotAuthorityRpcTarget = new NotAuthorityRpcTarget(manager);
+            m_AuthorityRpcTarget = new AuthorityRpcTarget(manager);
         }
     }
 }

Runtime/NetworkVariable/NetworkVariableSerialization.cs.meta

@@ -1,3 +0,0 @@
-fileFormatVersion: 2
-guid: 2c6ef5fdf2e94ec3b4ce8086d52700b3
-timeCreated: 1650985453

Runtime/NetworkVariable/Serialization.meta

@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: d960ae6c5b8241aa9e2906b709095ea1
+timeCreated: 1718215841

Runtime/NetworkVariable/Serialization/FallbackSerializer.cs

@@ -0,0 +1,99 @@
+using System;
+using Unity.Collections;
+
+namespace Unity.Netcode
+{
+    /// <summary>
+    /// This class is instantiated for types that we can't determine ahead of time are serializable - types
+    /// that don't meet any of the constraints for methods that are available on FastBufferReader and
+    /// FastBufferWriter. These types may or may not be serializable through extension methods. To ensure
+    /// the user has time to pass in the delegates to UserNetworkVariableSerialization, the existence
+    /// of user serialization isn't checked until it's used, so if no serialization is provided, this
+    /// will throw an exception when an object containing the relevant NetworkVariable is spawned.
+    /// </summary>
+    /// <typeparam name="T"></typeparam>
+    internal class FallbackSerializer<T> : INetworkVariableSerializer<T>
+    {
+        private void ThrowArgumentError()
+        {
+            throw new ArgumentException($"Serialization has not been generated for type {typeof(T).FullName}. This can be addressed by adding a [{nameof(GenerateSerializationForGenericParameterAttribute)}] to your generic class that serializes this value (if you are using one), adding [{nameof(GenerateSerializationForTypeAttribute)}(typeof({typeof(T).FullName})] to the class or method that is attempting to serialize it, or creating a field on a {nameof(NetworkBehaviour)} of type {nameof(NetworkVariable<T>)}. If this error continues to appear after doing one of those things and this is a type you can change, then either implement {nameof(INetworkSerializable)} or mark it as serializable by memcpy by adding {nameof(INetworkSerializeByMemcpy)} to its interface list to enable automatic serialization generation. If not, assign serialization code to {nameof(UserNetworkVariableSerialization<T>)}.{nameof(UserNetworkVariableSerialization<T>.WriteValue)}, {nameof(UserNetworkVariableSerialization<T>)}.{nameof(UserNetworkVariableSerialization<T>.ReadValue)}, and {nameof(UserNetworkVariableSerialization<T>)}.{nameof(UserNetworkVariableSerialization<T>.DuplicateValue)}, or if it's serializable by memcpy (contains no pointers), wrap it in {typeof(ForceNetworkSerializeByMemcpy<>).Name}.");
+        }
+
+        public void Write(FastBufferWriter writer, ref T value)
+        {
+            if (UserNetworkVariableSerialization<T>.ReadValue == null || UserNetworkVariableSerialization<T>.WriteValue == null || UserNetworkVariableSerialization<T>.DuplicateValue == null)
+            {
+                ThrowArgumentError();
+            }
+            UserNetworkVariableSerialization<T>.WriteValue(writer, value);
+        }
+        public void Read(FastBufferReader reader, ref T value)
+        {
+            if (UserNetworkVariableSerialization<T>.ReadValue == null || UserNetworkVariableSerialization<T>.WriteValue == null || UserNetworkVariableSerialization<T>.DuplicateValue == null)
+            {
+                ThrowArgumentError();
+            }
+            UserNetworkVariableSerialization<T>.ReadValue(reader, out value);
+        }
+
+        public void WriteDelta(FastBufferWriter writer, ref T value, ref T previousValue)
+        {
+            if (UserNetworkVariableSerialization<T>.ReadValue == null || UserNetworkVariableSerialization<T>.WriteValue == null || UserNetworkVariableSerialization<T>.DuplicateValue == null)
+            {
+                ThrowArgumentError();
+            }
+
+            if (UserNetworkVariableSerialization<T>.WriteDelta == null || UserNetworkVariableSerialization<T>.ReadDelta == null)
+            {
+                UserNetworkVariableSerialization<T>.WriteValue(writer, value);
+                return;
+            }
+            UserNetworkVariableSerialization<T>.WriteDelta(writer, value, previousValue);
+        }
+
+        public void ReadDelta(FastBufferReader reader, ref T value)
+        {
+            if (UserNetworkVariableSerialization<T>.ReadValue == null || UserNetworkVariableSerialization<T>.WriteValue == null || UserNetworkVariableSerialization<T>.DuplicateValue == null)
+            {
+                ThrowArgumentError();
+            }
+
+            if (UserNetworkVariableSerialization<T>.WriteDelta == null || UserNetworkVariableSerialization<T>.ReadDelta == null)
+            {
+                UserNetworkVariableSerialization<T>.ReadValue(reader, out value);
+                return;
+            }
+            UserNetworkVariableSerialization<T>.ReadDelta(reader, ref value);
+        }
+
+        void INetworkVariableSerializer<T>.ReadWithAllocator(FastBufferReader reader, out T value, Allocator allocator)
+        {
+            throw new NotImplementedException();
+        }
+
+        public void Duplicate(in T value, ref T duplicatedValue)
+        {
+            if (UserNetworkVariableSerialization<T>.ReadValue == null || UserNetworkVariableSerialization<T>.WriteValue == null || UserNetworkVariableSerialization<T>.DuplicateValue == null)
+            {
+                ThrowArgumentError();
+            }
+            UserNetworkVariableSerialization<T>.DuplicateValue(value, ref duplicatedValue);
+        }
+    }
+
+    // RuntimeAccessModifiersILPP will make this `public`
+    // This is just pass-through to NetworkVariableSerialization<T> but is here because I could not get ILPP
+    // to generate code that would successfully call Type<T>.Method(T), but it has no problem calling Type.Method<T>(T)
+    internal class RpcFallbackSerialization
+    {
+        public static void Write<T>(FastBufferWriter writer, ref T value)
+        {
+            NetworkVariableSerialization<T>.Write(writer, ref value);
+        }
+
+        public static void Read<T>(FastBufferReader reader, ref T value)
+        {
+            NetworkVariableSerialization<T>.Read(reader, ref value);
+        }
+    }
+}

Runtime/NetworkVariable/Serialization/FallbackSerializer.cs.meta

@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: 288dbe7d1ff74860ae3552c034485538
+timeCreated: 1718219109

Runtime/NetworkVariable/Serialization/INetworkVariableSerializer.cs

@@ -0,0 +1,26 @@
+using Unity.Collections;
+
+namespace Unity.Netcode
+{
+    /// <summary>
+    /// Interface used by NetworkVariables to serialize them
+    /// </summary>
+    ///
+    /// <typeparam name="T"></typeparam>
+    internal interface INetworkVariableSerializer<T>
+    {
+        // Write has to be taken by ref here because of INetworkSerializable
+        // Open Instance Delegates (pointers to methods without an instance attached to them)
+        // require the first parameter passed to them (the instance) to be passed by ref.
+        // So foo.Bar() becomes BarDelegate(ref foo);
+        // Taking T as an in parameter like we do in other places would require making a copy
+        // of it to pass it as a ref parameter.,
+
+        public void Write(FastBufferWriter writer, ref T value);
+        public void Read(FastBufferReader reader, ref T value);
+        public void WriteDelta(FastBufferWriter writer, ref T value, ref T previousValue);
+        public void ReadDelta(FastBufferReader reader, ref T value);
+        internal void ReadWithAllocator(FastBufferReader reader, out T value, Allocator allocator);
+        public void Duplicate(in T value, ref T duplicatedValue);
+    }
+}

Runtime/NetworkVariable/Serialization/INetworkVariableSerializer.cs.meta

@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: f78e258ef55f4ee89bc3f24d67b8d242
+timeCreated: 1718218205

Runtime/NetworkVariable/Serialization/NetworkVariableEquality.cs

@@ -0,0 +1,357 @@
+using System;
+using System.Collections.Generic;
+using Unity.Collections;
+using Unity.Collections.LowLevel.Unsafe;
+using Unity.Netcode;
+
+namespace Unity.Netcode
+{
+    internal static class NetworkVariableEquality<T>
+    {
+        // Compares two values of the same unmanaged type by underlying memory
+        // Ignoring any overridden value checks
+        // Size is fixed
+        internal static unsafe bool ValueEquals<TValueType>(ref TValueType a, ref TValueType b) where TValueType : unmanaged
+        {
+            // get unmanaged pointers
+            var aptr = UnsafeUtility.AddressOf(ref a);
+            var bptr = UnsafeUtility.AddressOf(ref b);
+
+            // compare addresses
+            return UnsafeUtility.MemCmp(aptr, bptr, sizeof(TValueType)) == 0;
+        }
+
+#if UNITY_NETCODE_NATIVE_COLLECTION_SUPPORT
+        // Compares two values of the same unmanaged type by underlying memory
+        // Ignoring any overridden value checks
+        // Size is fixed
+        internal static unsafe bool ValueEqualsList<TValueType>(ref NativeList<TValueType> a, ref NativeList<TValueType> b) where TValueType : unmanaged
+        {
+            if (a.IsCreated != b.IsCreated)
+            {
+                return false;
+            }
+
+            if (!a.IsCreated)
+            {
+                return true;
+            }
+
+            if (a.Length != b.Length)
+            {
+                return false;
+            }
+
+#if UTP_TRANSPORT_2_0_ABOVE
+            var aptr = a.GetUnsafePtr();
+            var bptr = b.GetUnsafePtr();
+#else
+            var aptr = (TValueType*)a.GetUnsafePtr();
+            var bptr = (TValueType*)b.GetUnsafePtr();
+#endif
+
+            return UnsafeUtility.MemCmp(aptr, bptr, sizeof(TValueType) * a.Length) == 0;
+        }
+#endif
+
+        // Compares two values of the same unmanaged type by underlying memory
+        // Ignoring any overridden value checks
+        // Size is fixed
+        internal static unsafe bool ValueEqualsArray<TValueType>(ref NativeArray<TValueType> a, ref NativeArray<TValueType> b) where TValueType : unmanaged
+        {
+            if (a.IsCreated != b.IsCreated)
+            {
+                return false;
+            }
+
+            if (!a.IsCreated)
+            {
+                return true;
+            }
+
+            if (a.Length != b.Length)
+            {
+                return false;
+            }
+
+            var aptr = (TValueType*)a.GetUnsafePtr();
+            var bptr = (TValueType*)b.GetUnsafePtr();
+            return UnsafeUtility.MemCmp(aptr, bptr, sizeof(TValueType) * a.Length) == 0;
+        }
+
+        internal static bool EqualityEqualsObject<TValueType>(ref TValueType a, ref TValueType b) where TValueType : class, IEquatable<TValueType>
+        {
+            if (a == null)
+            {
+                return b == null;
+            }
+
+            if (b == null)
+            {
+                return false;
+            }
+
+            return a.Equals(b);
+        }
+
+        internal static bool EqualityEquals<TValueType>(ref TValueType a, ref TValueType b) where TValueType : unmanaged, IEquatable<TValueType>
+        {
+            return a.Equals(b);
+        }
+
+        internal static bool EqualityEqualsList<TValueType>(ref List<TValueType> a, ref List<TValueType> b)
+        {
+            if (a == null != (b == null))
+            {
+                return false;
+            }
+
+            if (a == null)
+            {
+                return true;
+            }
+
+            if (a.Count != b.Count)
+            {
+                return false;
+            }
+
+            for (var i = 0; i < a.Count; ++i)
+            {
+                var aItem = a[i];
+                var bItem = b[i];
+                if (!NetworkVariableSerialization<TValueType>.AreEqual(ref aItem, ref bItem))
+                {
+                    return false;
+                }
+            }
+
+            return true;
+        }
+
+        internal static bool EqualityEqualsHashSet<TValueType>(ref HashSet<TValueType> a, ref HashSet<TValueType> b) where TValueType : IEquatable<TValueType>
+        {
+            if (a == null != (b == null))
+            {
+                return false;
+            }
+
+            if (a == null)
+            {
+                return true;
+            }
+
+            if (a.Count != b.Count)
+            {
+                return false;
+            }
+
+            foreach (var item in a)
+            {
+                if (!b.Contains(item))
+                {
+                    return false;
+                }
+            }
+
+            return true;
+        }
+
+        // Compares two values of the same unmanaged type by underlying memory
+        // Ignoring any overridden value checks
+        // Size is fixed
+        internal static unsafe bool EqualityEqualsArray<TValueType>(ref NativeArray<TValueType> a, ref NativeArray<TValueType> b) where TValueType : unmanaged, IEquatable<TValueType>
+        {
+            if (a.IsCreated != b.IsCreated)
+            {
+                return false;
+            }
+
+            if (!a.IsCreated)
+            {
+                return true;
+            }
+
+            if (a.Length != b.Length)
+            {
+                return false;
+            }
+
+            var aptr = (TValueType*)a.GetUnsafePtr();
+            var bptr = (TValueType*)b.GetUnsafePtr();
+            for (var i = 0; i < a.Length; ++i)
+            {
+                if (!EqualityEquals(ref aptr[i], ref bptr[i]))
+                {
+                    return false;
+                }
+            }
+
+            return true;
+        }
+
+        internal static bool ClassEquals<TValueType>(ref TValueType a, ref TValueType b) where TValueType : class
+        {
+            return a == b;
+        }
+
+#if UNITY_NETCODE_NATIVE_COLLECTION_SUPPORT
+        // Compares two values of the same unmanaged type by underlying memory
+        // Ignoring any overridden value checks
+        // Size is fixed
+        internal static unsafe bool EqualityEqualsNativeList<TValueType>(ref NativeList<TValueType> a, ref NativeList<TValueType> b) where TValueType : unmanaged, IEquatable<TValueType>
+        {
+            if (a.IsCreated != b.IsCreated)
+            {
+                return false;
+            }
+
+            if (!a.IsCreated)
+            {
+                return true;
+            }
+
+            if (a.Length != b.Length)
+            {
+                return false;
+            }
+
+#if UTP_TRANSPORT_2_0_ABOVE
+            var aptr = a.GetUnsafePtr();
+            var bptr = b.GetUnsafePtr();
+#else
+            var aptr = (TValueType*)a.GetUnsafePtr();
+            var bptr = (TValueType*)b.GetUnsafePtr();
+#endif
+            for (var i = 0; i < a.Length; ++i)
+            {
+                if (!EqualityEquals(ref aptr[i], ref bptr[i]))
+                {
+                    return false;
+                }
+            }
+
+            return true;
+        }
+
+        internal static bool EqualityEqualsNativeHashSet<TValueType>(ref NativeHashSet<TValueType> a, ref NativeHashSet<TValueType> b) where TValueType : unmanaged, IEquatable<TValueType>
+        {
+            if (a.IsCreated != b.IsCreated)
+            {
+                return false;
+            }
+
+            if (!a.IsCreated)
+            {
+                return true;
+            }
+
+#if UTP_TRANSPORT_2_0_ABOVE
+            if (a.Count != b.Count)
+#else
+            if (a.Count() != b.Count())
+#endif
+            {
+                return false;
+            }
+
+            foreach (var item in a)
+            {
+                if (!b.Contains(item))
+                {
+                    return false;
+                }
+            }
+
+            return true;
+        }
+#endif
+    }
+}
+
+/// <summary>
+///     Support methods for equality of NetworkVariable collection types.
+///     Because there are multiple overloads of WriteValue/ReadValue based on different generic constraints,
+///     but there's no way to achieve the same thing with a class, this sets up various read/write schemes
+///     based on which constraints are met by `T` using reflection, which is done at module load time.
+/// </summary>
+/// <typeparam name="TKey">The type the associated NetworkVariable dictionary collection key templated on</typeparam>
+/// <typeparam name="TVal">The type the associated NetworkVariable dictionary collection value templated on</typeparam>
+internal class NetworkVariableDictionarySerialization<TKey, TVal>
+    where TKey : IEquatable<TKey>
+{
+    internal static bool GenericEqualsDictionary(ref Dictionary<TKey, TVal> a, ref Dictionary<TKey, TVal> b)
+    {
+        if (a == null != (b == null))
+        {
+            return false;
+        }
+
+        if (a == null)
+        {
+            return true;
+        }
+
+        if (a.Count != b.Count)
+        {
+            return false;
+        }
+
+        foreach (var item in a)
+        {
+            var hasKey = b.TryGetValue(item.Key, out var val);
+            if (!hasKey)
+            {
+                return false;
+            }
+
+            var bVal = item.Value;
+            if (!NetworkVariableSerialization<TVal>.AreEqual(ref bVal, ref val))
+            {
+                return false;
+            }
+        }
+
+        return true;
+    }
+}
+
+#if UNITY_NETCODE_NATIVE_COLLECTION_SUPPORT
+internal class NetworkVariableMapSerialization<TKey, TVal>
+    where TKey : unmanaged, IEquatable<TKey>
+    where TVal : unmanaged
+{
+    internal static bool GenericEqualsNativeHashMap(ref NativeHashMap<TKey, TVal> a, ref NativeHashMap<TKey, TVal> b)
+    {
+        if (a.IsCreated != b.IsCreated)
+        {
+            return false;
+        }
+
+        if (!a.IsCreated)
+        {
+            return true;
+        }
+
+#if UTP_TRANSPORT_2_0_ABOVE
+        if (a.Count != b.Count)
+#else
+            if (a.Count() != b.Count())
+#endif
+        {
+            return false;
+        }
+
+        foreach (var item in a)
+        {
+            var hasKey = b.TryGetValue(item.Key, out var val);
+            if (!hasKey || !NetworkVariableSerialization<TVal>.AreEqual(ref item.Value, ref val))
+            {
+                return false;
+            }
+        }
+
+        return true;
+    }
+}
+#endif

Runtime/NetworkVariable/Serialization/NetworkVariableEquality.cs.meta

@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: 24b8352a975044509931bf684ccfdb82
+timeCreated: 1718219366

Runtime/NetworkVariable/Serialization/NetworkVariableSerialization.cs

@@ -0,0 +1,161 @@
+using System;
+
+namespace Unity.Netcode
+{
+    /// <summary>
+    ///     Support methods for reading/writing NetworkVariables
+    ///     Because there are multiple overloads of WriteValue/ReadValue based on different generic constraints,
+    ///     but there's no way to achieve the same thing with a class, this sets up various read/write schemes
+    ///     based on which constraints are met by `T` using reflection, which is done at module load time.
+    /// </summary>
+    /// <typeparam name="T">The type the associated NetworkVariable is templated on</typeparam>
+    [Serializable]
+    public static class NetworkVariableSerialization<T>
+    {
+        internal static INetworkVariableSerializer<T> Serializer = new FallbackSerializer<T>();
+
+        internal static bool IsDistributedAuthority => NetworkManager.IsDistributedAuthority;
+
+        /// <summary>
+        /// The collection item type tells the CMB server how to read the bytes of each item in the collection
+        /// </summary>
+        /// DANGO-EXP TODO: Determine if this is distributed authority only and impacts of this in client-server
+        internal static CollectionItemType Type = CollectionItemType.Unknown;
+
+        /// <summary>
+        /// A callback to check if two values are equal.
+        /// </summary>
+        public delegate bool EqualsDelegate(ref T a, ref T b);
+
+        /// <summary>
+        /// Uses the most efficient mechanism for a given type to determine if two values are equal.
+        /// For types that implement <see cref="IEquatable{T}"/>, it will call the Equals() method.
+        /// For unmanaged types, it will do a bytewise memory comparison.
+        /// For other types, it will call the == operator.
+        /// <br/>
+        /// <br/>
+        /// Note: If you are using this in a custom generic class, please make sure your class is
+        /// decorated with <see cref="GenerateSerializationForGenericParameterAttribute"/> so that codegen can
+        /// initialize the serialization mechanisms correctly. If your class is NOT
+        /// generic, it is better to check their equality yourself.
+        /// </summary>
+        public static EqualsDelegate AreEqual { get; internal set; }
+        /// <summary>
+        ///     Serialize a value using the best-known serialization method for a generic value.
+        ///     Will reliably serialize any value that is passed to it correctly with no boxing.
+        ///     <br />
+        ///     <br />
+        ///     Note: If you are using this in a custom generic class, please make sure your class is
+        ///     decorated with <see cref="GenerateSerializationForGenericParameterAttribute" /> so that codegen can
+        ///     initialize the serialization mechanisms correctly. If your class is NOT
+        ///     generic, it is better to use FastBufferWriter directly.
+        ///     <br />
+        ///     <br />
+        ///     If the codegen is unable to determine a serializer for a type,
+        ///     <see cref="UserNetworkVariableSerialization{T}" />.<see cref="UserNetworkVariableSerialization{T}.WriteValue" /> is called, which, by default,
+        ///     will throw an exception, unless you have assigned a user serialization callback to it at runtime.
+        /// </summary>
+        /// <param name="writer"></param>
+        /// <param name="value"></param>
+        public static void Write(FastBufferWriter writer, ref T value)
+        {
+            Serializer.Write(writer, ref value);
+        }
+
+        /// <summary>
+        ///     Deserialize a value using the best-known serialization method for a generic value.
+        ///     Will reliably deserialize any value that is passed to it correctly with no boxing.
+        ///     For types whose deserialization can be determined by codegen (which is most types),
+        ///     GC will only be incurred if the type is a managed type and the ref value passed in is `null`,
+        ///     in which case a new value is created; otherwise, it will be deserialized in-place.
+        ///     <br />
+        ///     <br />
+        ///     Note: If you are using this in a custom generic class, please make sure your class is
+        ///     decorated with <see cref="GenerateSerializationForGenericParameterAttribute" /> so that codegen can
+        ///     initialize the serialization mechanisms correctly. If your class is NOT
+        ///     generic, it is better to use FastBufferReader directly.
+        ///     <br />
+        ///     <br />
+        ///     If the codegen is unable to determine a serializer for a type,
+        ///     <see cref="UserNetworkVariableSerialization{T}" />.<see cref="UserNetworkVariableSerialization{T}.ReadValue" /> is called, which, by default,
+        ///     will throw an exception, unless you have assigned a user deserialization callback to it at runtime.
+        /// </summary>
+        /// <param name="reader"></param>
+        /// <param name="value"></param>
+        public static void Read(FastBufferReader reader, ref T value)
+        {
+            Serializer.Read(reader, ref value);
+        }
+
+        /// <summary>
+        ///     Serialize a value using the best-known serialization method for a generic value.
+        ///     Will reliably serialize any value that is passed to it correctly with no boxing.
+        ///     <br />
+        ///     <br />
+        ///     Note: If you are using this in a custom generic class, please make sure your class is
+        ///     decorated with <see cref="GenerateSerializationForGenericParameterAttribute" /> so that codegen can
+        ///     initialize the serialization mechanisms correctly. If your class is NOT
+        ///     generic, it is better to use FastBufferWriter directly.
+        ///     <br />
+        ///     <br />
+        ///     If the codegen is unable to determine a serializer for a type,
+        ///     <see cref="UserNetworkVariableSerialization{T}" />.<see cref="UserNetworkVariableSerialization{T}.WriteValue" /> is called, which, by default,
+        ///     will throw an exception, unless you have assigned a user serialization callback to it at runtime.
+        /// </summary>
+        /// <param name="writer"></param>
+        /// <param name="value"></param>
+        public static void WriteDelta(FastBufferWriter writer, ref T value, ref T previousValue)
+        {
+            Serializer.WriteDelta(writer, ref value, ref previousValue);
+        }
+
+        /// <summary>
+        ///     Deserialize a value using the best-known serialization method for a generic value.
+        ///     Will reliably deserialize any value that is passed to it correctly with no boxing.
+        ///     For types whose deserialization can be determined by codegen (which is most types),
+        ///     GC will only be incurred if the type is a managed type and the ref value passed in is `null`,
+        ///     in which case a new value is created; otherwise, it will be deserialized in-place.
+        ///     <br />
+        ///     <br />
+        ///     Note: If you are using this in a custom generic class, please make sure your class is
+        ///     decorated with <see cref="GenerateSerializationForGenericParameterAttribute" /> so that codegen can
+        ///     initialize the serialization mechanisms correctly. If your class is NOT
+        ///     generic, it is better to use FastBufferReader directly.
+        ///     <br />
+        ///     <br />
+        ///     If the codegen is unable to determine a serializer for a type,
+        ///     <see cref="UserNetworkVariableSerialization{T}" />.<see cref="UserNetworkVariableSerialization{T}.ReadValue" /> is called, which, by default,
+        ///     will throw an exception, unless you have assigned a user deserialization callback to it at runtime.
+        /// </summary>
+        /// <param name="reader"></param>
+        /// <param name="value"></param>
+        public static void ReadDelta(FastBufferReader reader, ref T value)
+        {
+            Serializer.ReadDelta(reader, ref value);
+        }
+
+        /// <summary>
+        ///     Duplicates a value using the most efficient means of creating a complete copy.
+        ///     For most types this is a simple assignment or memcpy.
+        ///     For managed types, this is will serialize and then deserialize the value to ensure
+        ///     a correct copy.
+        ///     <br />
+        ///     <br />
+        ///     Note: If you are using this in a custom generic class, please make sure your class is
+        ///     decorated with <see cref="GenerateSerializationForGenericParameterAttribute" /> so that codegen can
+        ///     initialize the serialization mechanisms correctly. If your class is NOT
+        ///     generic, it is better to duplicate it directly.
+        ///     <br />
+        ///     <br />
+        ///     If the codegen is unable to determine a serializer for a type,
+        ///     <see cref="UserNetworkVariableSerialization{T}" />.<see cref="UserNetworkVariableSerialization{T}.DuplicateValue" /> is called, which, by default,
+        ///     will throw an exception, unless you have assigned a user duplication callback to it at runtime.
+        /// </summary>
+        /// <param name="value"></param>
+        /// <param name="duplicatedValue"></param>
+        public static void Duplicate(in T value, ref T duplicatedValue)
+        {
+            Serializer.Duplicate(value, ref duplicatedValue);
+        }
+    }
+}

Runtime/NetworkVariable/Serialization/NetworkVariableSerialization.cs.meta

@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: 7a943170e35746e8913dd494d79bb63d
+timeCreated: 1718215899

Runtime/NetworkVariable/Serialization/TypedILPPInitializers.cs

@@ -0,0 +1,325 @@
+using System;
+using System.Collections.Generic;
+using Unity.Collections;
+using UnityEditor;
+using UnityEngine;
+
+namespace Unity.Netcode
+{
+    /// <summary>
+    /// This class contains initialization functions for various different types used in NetworkVariables.
+    /// Generally speaking, these methods are called by a module initializer created by codegen (NetworkBehaviourILPP)
+    /// and do not need to be called manually.
+    ///
+    /// There are two types of initializers: Serializers and EqualityCheckers. Every type must have an EqualityChecker
+    /// registered to it in order to be used in NetworkVariable; however, not all types need a Serializer. Types without
+    /// a serializer registered will fall back to using the delegates in <see cref="UserNetworkVariableSerialization{T}"/>.
+    /// If no such delegate has been registered, a type without a serializer will throw an exception on the first attempt
+    /// to serialize or deserialize it. (Again, however, codegen handles this automatically and this registration doesn't
+    /// typically need to be performed manually.)
+    /// </summary>
+    public static class NetworkVariableSerializationTypedInitializers
+    {
+        [RuntimeInitializeOnLoadMethod(RuntimeInitializeLoadType.AfterAssembliesLoaded)]
+#if UNITY_EDITOR
+        [InitializeOnLoadMethod]
+#endif
+        internal static void InitializeIntegerSerialization()
+        {
+            NetworkVariableSerialization<short>.Serializer = new ShortSerializer();
+            NetworkVariableSerialization<short>.AreEqual = NetworkVariableEquality<short>.ValueEquals;
+            NetworkVariableSerialization<ushort>.Serializer = new UshortSerializer();
+            NetworkVariableSerialization<ushort>.AreEqual = NetworkVariableEquality<ushort>.ValueEquals;
+            NetworkVariableSerialization<int>.Serializer = new IntSerializer();
+            NetworkVariableSerialization<int>.AreEqual = NetworkVariableEquality<int>.ValueEquals;
+            NetworkVariableSerialization<uint>.Serializer = new UintSerializer();
+            NetworkVariableSerialization<uint>.AreEqual = NetworkVariableEquality<uint>.ValueEquals;
+            NetworkVariableSerialization<long>.Serializer = new LongSerializer();
+            NetworkVariableSerialization<long>.AreEqual = NetworkVariableEquality<long>.ValueEquals;
+            NetworkVariableSerialization<ulong>.Serializer = new UlongSerializer();
+            NetworkVariableSerialization<ulong>.AreEqual = NetworkVariableEquality<ulong>.ValueEquals;
+
+            // DANGO-EXP TODO: Determine if this is distributed authority only and impacts of this in client-server
+            NetworkVariableSerialization<short>.Type = CollectionItemType.Short;
+            NetworkVariableSerialization<ushort>.Type = CollectionItemType.UShort;
+            NetworkVariableSerialization<int>.Type = CollectionItemType.Int;
+            NetworkVariableSerialization<uint>.Type = CollectionItemType.UInt;
+            NetworkVariableSerialization<long>.Type = CollectionItemType.Long;
+            NetworkVariableSerialization<ulong>.Type = CollectionItemType.ULong;
+        }
+
+        /// <summary>
+        /// Registeres an unmanaged type that will be serialized by a direct memcpy into a buffer
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public static void InitializeSerializer_UnmanagedByMemcpy<T>() where T : unmanaged
+        {
+            NetworkVariableSerialization<T>.Serializer = new UnmanagedTypeSerializer<T>();
+            // DANGO-EXP TODO: Determine if this is distributed authority only and impacts of this in client-server
+            NetworkVariableSerialization<T>.Type = CollectionItemType.Unmanaged;
+        }
+
+        /// <summary>
+        /// Registeres an unmanaged type that will be serialized by a direct memcpy into a buffer
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public static void InitializeSerializer_UnmanagedByMemcpyArray<T>() where T : unmanaged
+        {
+            NetworkVariableSerialization<NativeArray<T>>.Serializer = new UnmanagedArraySerializer<T>();
+        }
+
+#if UNITY_NETCODE_NATIVE_COLLECTION_SUPPORT
+        /// <summary>
+        /// Registeres an unmanaged type that will be serialized by a direct memcpy into a buffer
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public static void InitializeSerializer_UnmanagedByMemcpyList<T>() where T : unmanaged
+        {
+            NetworkVariableSerialization<NativeList<T>>.Serializer = new UnmanagedListSerializer<T>();
+        }
+
+        /// <summary>
+        /// Registeres a native hash set (this generic implementation works with all types)
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public static void InitializeSerializer_NativeHashSet<T>() where T : unmanaged, IEquatable<T>
+        {
+            NetworkVariableSerialization<NativeHashSet<T>>.Serializer = new NativeHashSetSerializer<T>();
+        }
+
+        /// <summary>
+        /// Registeres a native hash set (this generic implementation works with all types)
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public static void InitializeSerializer_NativeHashMap<TKey, TVal>()
+            where TKey : unmanaged, IEquatable<TKey>
+            where TVal : unmanaged
+        {
+            NetworkVariableSerialization<NativeHashMap<TKey, TVal>>.Serializer = new NativeHashMapSerializer<TKey, TVal>();
+        }
+#endif
+
+        /// <summary>
+        /// Registeres a native hash set (this generic implementation works with all types)
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public static void InitializeSerializer_List<T>()
+        {
+            NetworkVariableSerialization<List<T>>.Serializer = new ListSerializer<T>();
+        }
+
+        /// <summary>
+        /// Registeres a native hash set (this generic implementation works with all types)
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public static void InitializeSerializer_HashSet<T>() where T : IEquatable<T>
+        {
+            NetworkVariableSerialization<HashSet<T>>.Serializer = new HashSetSerializer<T>();
+        }
+
+        /// <summary>
+        /// Registeres a native hash set (this generic implementation works with all types)
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public static void InitializeSerializer_Dictionary<TKey, TVal>() where TKey : IEquatable<TKey>
+        {
+            NetworkVariableSerialization<Dictionary<TKey, TVal>>.Serializer = new DictionarySerializer<TKey, TVal>();
+        }
+
+        /// <summary>
+        /// Registers an unmanaged type that implements INetworkSerializable and will be serialized through a call to
+        /// NetworkSerialize
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public static void InitializeSerializer_UnmanagedINetworkSerializable<T>() where T : unmanaged, INetworkSerializable
+        {
+            NetworkVariableSerialization<T>.Serializer = new UnmanagedNetworkSerializableSerializer<T>();
+        }
+
+        /// <summary>
+        /// Registers an unmanaged type that implements INetworkSerializable and will be serialized through a call to
+        /// NetworkSerialize
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public static void InitializeSerializer_UnmanagedINetworkSerializableArray<T>() where T : unmanaged, INetworkSerializable
+        {
+            NetworkVariableSerialization<NativeArray<T>>.Serializer = new UnmanagedNetworkSerializableArraySerializer<T>();
+        }
+
+#if UNITY_NETCODE_NATIVE_COLLECTION_SUPPORT
+        /// <summary>
+        /// Registers an unmanaged type that implements INetworkSerializable and will be serialized through a call to
+        /// NetworkSerialize
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public static void InitializeSerializer_UnmanagedINetworkSerializableList<T>() where T : unmanaged, INetworkSerializable
+        {
+            NetworkVariableSerialization<NativeList<T>>.Serializer = new UnmanagedNetworkSerializableListSerializer<T>();
+        }
+#endif
+
+        /// <summary>
+        /// Registers a managed type that implements INetworkSerializable and will be serialized through a call to
+        /// NetworkSerialize
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public static void InitializeSerializer_ManagedINetworkSerializable<T>() where T : class, INetworkSerializable, new()
+        {
+            NetworkVariableSerialization<T>.Serializer = new ManagedNetworkSerializableSerializer<T>();
+        }
+
+        /// <summary>
+        /// Registers a FixedString type that will be serialized through FastBufferReader/FastBufferWriter's FixedString
+        /// serializers
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public static void InitializeSerializer_FixedString<T>() where T : unmanaged, INativeList<byte>, IUTF8Bytes
+        {
+            NetworkVariableSerialization<T>.Serializer = new FixedStringSerializer<T>();
+        }
+
+        /// <summary>
+        /// Registers a FixedString type that will be serialized through FastBufferReader/FastBufferWriter's FixedString
+        /// serializers
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public static void InitializeSerializer_FixedStringArray<T>() where T : unmanaged, INativeList<byte>, IUTF8Bytes
+        {
+            NetworkVariableSerialization<NativeArray<T>>.Serializer = new FixedStringArraySerializer<T>();
+        }
+
+#if UNITY_NETCODE_NATIVE_COLLECTION_SUPPORT
+        /// <summary>
+        /// Registers a FixedString type that will be serialized through FastBufferReader/FastBufferWriter's FixedString
+        /// serializers
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public static void InitializeSerializer_FixedStringList<T>() where T : unmanaged, INativeList<byte>, IUTF8Bytes
+        {
+            NetworkVariableSerialization<NativeList<T>>.Serializer = new FixedStringListSerializer<T>();
+        }
+#endif
+
+        /// <summary>
+        /// Registers a managed type that will be checked for equality using T.Equals()
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public static void InitializeEqualityChecker_ManagedIEquatable<T>() where T : class, IEquatable<T>
+        {
+            NetworkVariableSerialization<T>.AreEqual = NetworkVariableEquality<T>.EqualityEqualsObject;
+        }
+
+        /// <summary>
+        /// Registers an unmanaged type that will be checked for equality using T.Equals()
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public static void InitializeEqualityChecker_UnmanagedIEquatable<T>() where T : unmanaged, IEquatable<T>
+        {
+            NetworkVariableSerialization<T>.AreEqual = NetworkVariableEquality<T>.EqualityEquals;
+        }
+
+        /// <summary>
+        /// Registers an unmanaged type that will be checked for equality using T.Equals()
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public static void InitializeEqualityChecker_UnmanagedIEquatableArray<T>() where T : unmanaged, IEquatable<T>
+        {
+            NetworkVariableSerialization<NativeArray<T>>.AreEqual = NetworkVariableEquality<T>.EqualityEqualsArray;
+        }
+        /// <summary>
+        /// Registers an unmanaged type that will be checked for equality using T.Equals()
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public static void InitializeEqualityChecker_List<T>()
+        {
+            NetworkVariableSerialization<List<T>>.AreEqual = NetworkVariableEquality<T>.EqualityEqualsList;
+        }
+        /// <summary>
+        /// Registers an unmanaged type that will be checked for equality using T.Equals()
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public static void InitializeEqualityChecker_HashSet<T>() where T : IEquatable<T>
+        {
+            NetworkVariableSerialization<HashSet<T>>.AreEqual = NetworkVariableEquality<T>.EqualityEqualsHashSet;
+        }
+        /// <summary>
+        /// Registers an unmanaged type that will be checked for equality using T.Equals()
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public static void InitializeEqualityChecker_Dictionary<TKey, TVal>()
+            where TKey : IEquatable<TKey>
+        {
+            NetworkVariableSerialization<Dictionary<TKey, TVal>>.AreEqual = NetworkVariableDictionarySerialization<TKey, TVal>.GenericEqualsDictionary;
+        }
+
+#if UNITY_NETCODE_NATIVE_COLLECTION_SUPPORT
+        /// <summary>
+        /// Registers an unmanaged type that will be checked for equality using T.Equals()
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public static void InitializeEqualityChecker_UnmanagedIEquatableList<T>() where T : unmanaged, IEquatable<T>
+        {
+            NetworkVariableSerialization<NativeList<T>>.AreEqual = NetworkVariableEquality<T>.EqualityEqualsNativeList;
+        }
+        /// <summary>
+        /// Registers an unmanaged type that will be checked for equality using T.Equals()
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public static void InitializeEqualityChecker_NativeHashSet<T>() where T : unmanaged, IEquatable<T>
+        {
+            NetworkVariableSerialization<NativeHashSet<T>>.AreEqual = NetworkVariableEquality<T>.EqualityEqualsNativeHashSet;
+        }
+        /// <summary>
+        /// Registers an unmanaged type that will be checked for equality using T.Equals()
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public static void InitializeEqualityChecker_NativeHashMap<TKey, TVal>()
+            where TKey : unmanaged, IEquatable<TKey>
+            where TVal : unmanaged
+        {
+            NetworkVariableSerialization<NativeHashMap<TKey, TVal>>.AreEqual = NetworkVariableMapSerialization<TKey, TVal>.GenericEqualsNativeHashMap;
+        }
+#endif
+
+        /// <summary>
+        /// Registers an unmanaged type that will be checked for equality using memcmp and only considered
+        /// equal if they are bitwise equivalent in memory
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public static void InitializeEqualityChecker_UnmanagedValueEquals<T>() where T : unmanaged
+        {
+            NetworkVariableSerialization<T>.AreEqual = NetworkVariableEquality<T>.ValueEquals;
+        }
+
+        /// <summary>
+        /// Registers an unmanaged type that will be checked for equality using memcmp and only considered
+        /// equal if they are bitwise equivalent in memory
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public static void InitializeEqualityChecker_UnmanagedValueEqualsArray<T>() where T : unmanaged
+        {
+            NetworkVariableSerialization<NativeArray<T>>.AreEqual = NetworkVariableEquality<T>.ValueEqualsArray;
+        }
+
+#if UNITY_NETCODE_NATIVE_COLLECTION_SUPPORT
+        /// <summary>
+        /// Registers an unmanaged type that will be checked for equality using memcmp and only considered
+        /// equal if they are bitwise equivalent in memory
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public static void InitializeEqualityChecker_UnmanagedValueEqualsList<T>() where T : unmanaged
+        {
+            NetworkVariableSerialization<NativeList<T>>.AreEqual = NetworkVariableEquality<T>.ValueEqualsList;
+        }
+#endif
+
+        /// <summary>
+        /// Registers a managed type that will be checked for equality using the == operator
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        public static void InitializeEqualityChecker_ManagedClassEquals<T>() where T : class
+        {
+            NetworkVariableSerialization<T>.AreEqual = NetworkVariableEquality<T>.ClassEquals;
+        }
+    }
+}

Runtime/NetworkVariable/Serialization/TypedILPPInitializers.cs.meta

@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: 65bdb3e11a9a412ab5e936a9c96a3da0
+timeCreated: 1718216842

Runtime/NetworkVariable/Serialization/TypedSerializerImplementations.cs.meta

@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: bbfa170e9dd448bbbe381ce38d5c139d
+timeCreated: 1718216671

Runtime/NetworkVariable/Serialization/UserNetworkVariableSerialization.cs

@@ -0,0 +1,73 @@
+namespace Unity.Netcode
+{
+    /// <summary>
+    /// This class is used to register user serialization with NetworkVariables for types
+    /// that are serialized via user serialization, such as with FastBufferReader and FastBufferWriter
+    /// extension methods. Finding those methods isn't achievable efficiently at runtime, so this allows
+    /// users to tell NetworkVariable about those extension methods (or simply pass in a lambda)
+    /// </summary>
+    /// <typeparam name="T"></typeparam>
+    public class UserNetworkVariableSerialization<T>
+    {
+        /// <summary>
+        /// The write value delegate handler definition
+        /// </summary>
+        /// <param name="writer">The <see cref="FastBufferWriter"/> to write the value of type `T`</param>
+        /// <param name="value">The value of type `T` to be written</param>
+        public delegate void WriteValueDelegate(FastBufferWriter writer, in T value);
+
+        /// <summary>
+        /// The write value delegate handler definition
+        /// </summary>
+        /// <param name="writer">The <see cref="FastBufferWriter"/> to write the value of type `T`</param>
+        /// <param name="value">The value of type `T` to be written</param>
+        public delegate void WriteDeltaDelegate(FastBufferWriter writer, in T value, in T previousValue);
+
+        /// <summary>
+        /// The read value delegate handler definition
+        /// </summary>
+        /// <param name="reader">The <see cref="FastBufferReader"/> to read the value of type `T`</param>
+        /// <param name="value">The value of type `T` to be read</param>
+        public delegate void ReadValueDelegate(FastBufferReader reader, out T value);
+
+        /// <summary>
+        /// The read value delegate handler definition
+        /// </summary>
+        /// <param name="reader">The <see cref="FastBufferReader"/> to read the value of type `T`</param>
+        /// <param name="value">The value of type `T` to be read</param>
+        public delegate void ReadDeltaDelegate(FastBufferReader reader, ref T value);
+
+        /// <summary>
+        /// The read value delegate handler definition
+        /// </summary>
+        /// <param name="reader">The <see cref="FastBufferReader"/> to read the value of type `T`</param>
+        /// <param name="value">The value of type `T` to be read</param>
+        public delegate void DuplicateValueDelegate(in T value, ref T duplicatedValue);
+
+        /// <summary>
+        /// Callback to write a value
+        /// </summary>
+        public static WriteValueDelegate WriteValue;
+
+        /// <summary>
+        /// Callback to read a value
+        /// </summary>
+        public static ReadValueDelegate ReadValue;
+
+        /// <summary>
+        /// Callback to write a delta between two values, based on computing the difference between the previous and
+        /// current values.
+        /// </summary>
+        public static WriteDeltaDelegate WriteDelta;
+
+        /// <summary>
+        /// Callback to read a delta, applying only select changes to the current value.
+        /// </summary>
+        public static ReadDeltaDelegate ReadDelta;
+
+        /// <summary>
+        /// Callback to create a duplicate of a value, used to check for dirty status.
+        /// </summary>
+        public static DuplicateValueDelegate DuplicateValue;
+    }
+}

Runtime/NetworkVariable/Serialization/UserNetworkVariableSerialization.cs.meta

@@ -0,0 +1,3 @@
+fileFormatVersion: 2
+guid: b295a6756640488b9824d2ec6e26ddae
+timeCreated: 1718218272

Runtime/Serialization/FastBufferReader.cs

@@ -523,8 +523,8 @@ namespace Unity.Netcode
         /// <param name="oneByteChars">Whether or not to use one byte per character. This will only allow ASCII</param>
         public unsafe void ReadValue(out string s, bool oneByteChars = false)
         {
-            ReadValue(out uint length);
-            s = "".PadRight((int)length);
+            ReadLength(out int length);
+            s = "".PadRight(length);
             int target = s.Length;
             fixed (char* native = s)
             {
@@ -562,18 +562,18 @@ namespace Unity.Netcode
             }
 #endif
 
-            if (!TryBeginReadInternal(sizeof(uint)))
+            if (!TryBeginReadInternal(SizeOfLengthField()))
             {
                 throw new OverflowException("Reading past the end of the buffer");
             }
 
-            ReadValue(out uint length);
+            ReadLength(out int length);
 
-            if (!TryBeginReadInternal((int)length * (oneByteChars ? 1 : sizeof(char))))
+            if (!TryBeginReadInternal(length * (oneByteChars ? 1 : sizeof(char))))
             {
                 throw new OverflowException("Reading past the end of the buffer");
             }
-            s = "".PadRight((int)length);
+            s = "".PadRight(length);
             int target = s.Length;
             fixed (char* native = s)
             {
@@ -592,6 +592,33 @@ namespace Unity.Netcode
             }
         }
 
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private static int SizeOfLengthField() => sizeof(uint);
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private void ReadLengthSafe(out uint length) => ReadUnmanagedSafe(out length);
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private void ReadLength(out uint length) => ReadUnmanaged(out length);
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private void ReadLengthSafe(out int length)
+        {
+            ReadLengthSafe(out uint temp);
+            if (temp > int.MaxValue)
+            {
+                throw new InvalidCastException("length value outside of int32 range");
+            }
+            length = (int)temp;
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private void ReadLength(out int length)
+        {
+            ReadLength(out uint temp);
+            length = (int)temp;
+        }
+
         /// <summary>
         /// Read a partial value. The value is zero-initialized and then the specified number of bytes is read into it.
         /// </summary>
@@ -777,7 +804,7 @@ namespace Unity.Netcode
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         internal unsafe void ReadUnmanaged<T>(out T[] value) where T : unmanaged
         {
-            ReadUnmanaged(out int sizeInTs);
+            ReadLength(out int sizeInTs);
             int sizeInBytes = sizeInTs * sizeof(T);
             value = new T[sizeInTs];
             fixed (T* ptr = value)
@@ -789,7 +816,7 @@ namespace Unity.Netcode
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         internal unsafe void ReadUnmanagedSafe<T>(out T[] value) where T : unmanaged
         {
-            ReadUnmanagedSafe(out int sizeInTs);
+            ReadLengthSafe(out int sizeInTs);
             int sizeInBytes = sizeInTs * sizeof(T);
             value = new T[sizeInTs];
             fixed (T* ptr = value)
@@ -801,7 +828,7 @@ namespace Unity.Netcode
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         internal unsafe void ReadUnmanaged<T>(out NativeArray<T> value, Allocator allocator) where T : unmanaged
         {
-            ReadUnmanaged(out int sizeInTs);
+            ReadLength(out int sizeInTs);
             int sizeInBytes = sizeInTs * sizeof(T);
             value = new NativeArray<T>(sizeInTs, allocator);
             byte* bytes = (byte*)value.GetUnsafePtr();
@@ -810,7 +837,7 @@ namespace Unity.Netcode
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         internal unsafe void ReadUnmanagedSafe<T>(out NativeArray<T> value, Allocator allocator) where T : unmanaged
         {
-            ReadUnmanagedSafe(out int sizeInTs);
+            ReadLengthSafe(out int sizeInTs);
             int sizeInBytes = sizeInTs * sizeof(T);
             value = new NativeArray<T>(sizeInTs, allocator);
             byte* bytes = (byte*)value.GetUnsafePtr();
@@ -820,7 +847,7 @@ namespace Unity.Netcode
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         internal unsafe void ReadUnmanagedInPlace<T>(ref NativeList<T> value) where T : unmanaged
         {
-            ReadUnmanaged(out int sizeInTs);
+            ReadLength(out int sizeInTs);
             int sizeInBytes = sizeInTs * sizeof(T);
             value.Resize(sizeInTs, NativeArrayOptions.UninitializedMemory);
             byte* bytes = (byte*)value.GetUnsafePtr();
@@ -829,7 +856,7 @@ namespace Unity.Netcode
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         internal unsafe void ReadUnmanagedSafeInPlace<T>(ref NativeList<T> value) where T : unmanaged
         {
-            ReadUnmanagedSafe(out int sizeInTs);
+            ReadLengthSafe(out int sizeInTs);
             int sizeInBytes = sizeInTs * sizeof(T);
             value.Resize(sizeInTs, NativeArrayOptions.UninitializedMemory);
             byte* bytes = (byte*)value.GetUnsafePtr();
@@ -1078,7 +1105,7 @@ namespace Unity.Netcode
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         internal void ReadValueSafeInPlace<T>(ref NativeHashSet<T> value) where T : unmanaged, IEquatable<T>
         {
-            ReadUnmanagedSafe(out int length);
+            ReadLengthSafe(out int length);
             value.Clear();
             for (var i = 0; i < length; ++i)
             {
@@ -1093,7 +1120,7 @@ namespace Unity.Netcode
             where TKey : unmanaged, IEquatable<TKey>
             where TVal : unmanaged
         {
-            ReadUnmanagedSafe(out int length);
+            ReadLengthSafe(out int length);
             value.Clear();
             for (var i = 0; i < length; ++i)
             {
@@ -1553,7 +1580,7 @@ namespace Unity.Netcode
         /// This method is a little difficult to use, since you have to know the size of the string before
         /// reading it, but is useful when the string is a known, fixed size. Note that the size of the
         /// string is also encoded, so the size to call TryBeginRead on is actually the fixed size (in bytes)
-        /// plus sizeof(int)
+        /// plus sizeof(uint)
         /// </summary>
         /// <param name="value">the value to read</param>
         /// <param name="unused">An unused parameter used for enabling overload resolution based on generic constraints</param>
@@ -1562,7 +1589,7 @@ namespace Unity.Netcode
         public unsafe void ReadValue<T>(out T value, FastBufferWriter.ForFixedStrings unused = default)
             where T : unmanaged, INativeList<byte>, IUTF8Bytes
         {
-            ReadUnmanaged(out int length);
+            ReadLength(out int length);
             value = new T
             {
                 Length = length
@@ -1584,7 +1611,7 @@ namespace Unity.Netcode
         public unsafe void ReadValueSafe<T>(out T value, FastBufferWriter.ForFixedStrings unused = default)
             where T : unmanaged, INativeList<byte>, IUTF8Bytes
         {
-            ReadUnmanagedSafe(out int length);
+            ReadLengthSafe(out int length);
             value = new T
             {
                 Length = length
@@ -1606,7 +1633,7 @@ namespace Unity.Netcode
         public unsafe void ReadValueSafeInPlace<T>(ref T value, FastBufferWriter.ForFixedStrings unused = default)
             where T : unmanaged, INativeList<byte>, IUTF8Bytes
         {
-            ReadUnmanagedSafe(out int length);
+            ReadLengthSafe(out int length);
             value.Length = length;
             ReadBytesSafe(value.GetUnsafePtr(), length);
         }
@@ -1625,7 +1652,7 @@ namespace Unity.Netcode
         public unsafe void ReadValueSafe<T>(out NativeArray<T> value, Allocator allocator)
             where T : unmanaged, INativeList<byte>, IUTF8Bytes
         {
-            ReadUnmanagedSafe(out int length);
+            ReadLengthSafe(out int length);
             value = new NativeArray<T>(length, allocator);
             var ptr = (T*)value.GetUnsafePtr();
             for (var i = 0; i < length; ++i)
@@ -1647,7 +1674,7 @@ namespace Unity.Netcode
         public unsafe void ReadValueSafeTemp<T>(out NativeArray<T> value)
             where T : unmanaged, INativeList<byte>, IUTF8Bytes
         {
-            ReadUnmanagedSafe(out int length);
+            ReadLengthSafe(out int length);
             value = new NativeArray<T>(length, Allocator.Temp);
             var ptr = (T*)value.GetUnsafePtr();
             for (var i = 0; i < length; ++i)
@@ -1669,7 +1696,7 @@ namespace Unity.Netcode
         public void ReadValueSafe<T>(out T[] value, FastBufferWriter.ForFixedStrings unused = default)
             where T : unmanaged, INativeList<byte>, IUTF8Bytes
         {
-            ReadUnmanagedSafe(out int length);
+            ReadLengthSafe(out int length);
             value = new T[length];
             for (var i = 0; i < length; ++i)
             {
@@ -1691,7 +1718,7 @@ namespace Unity.Netcode
         public void ReadValueSafeInPlace<T>(ref NativeList<T> value)
             where T : unmanaged, INativeList<byte>, IUTF8Bytes
         {
-            ReadUnmanagedSafe(out int length);
+            ReadLengthSafe(out int length);
             value.Resize(length, NativeArrayOptions.UninitializedMemory);
             for (var i = 0; i < length; ++i)
             {

Runtime/Serialization/FastBufferWriter.cs

@@ -421,7 +421,7 @@ namespace Unity.Netcode
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public static int GetWriteSize(string s, bool oneByteChars = false)
         {
-            return sizeof(int) + s.Length * (oneByteChars ? sizeof(byte) : sizeof(char));
+            return SizeOfLengthField() + s.Length * (oneByteChars ? sizeof(byte) : sizeof(char));
         }
 
         /// <summary>
@@ -445,7 +445,7 @@ namespace Unity.Netcode
         public void WriteNetworkSerializable<T>(T[] array, int count = -1, int offset = 0) where T : INetworkSerializable
         {
             int sizeInTs = count != -1 ? count : array.Length - offset;
-            WriteValueSafe(sizeInTs);
+            WriteLengthSafe(sizeInTs);
             foreach (var item in array)
             {
                 WriteNetworkSerializable(item);
@@ -462,7 +462,7 @@ namespace Unity.Netcode
         public void WriteNetworkSerializable<T>(NativeArray<T> array, int count = -1, int offset = 0) where T : unmanaged, INetworkSerializable
         {
             int sizeInTs = count != -1 ? count : array.Length - offset;
-            WriteValueSafe(sizeInTs);
+            WriteLengthSafe(sizeInTs);
             foreach (var item in array)
             {
                 WriteNetworkSerializable(item);
@@ -480,7 +480,7 @@ namespace Unity.Netcode
         public void WriteNetworkSerializable<T>(NativeList<T> array, int count = -1, int offset = 0) where T : unmanaged, INetworkSerializable
         {
             int sizeInTs = count != -1 ? count : array.Length - offset;
-            WriteValueSafe(sizeInTs);
+            WriteLengthSafe(sizeInTs);
             foreach (var item in array)
             {
                 WriteNetworkSerializable(item);
@@ -495,7 +495,7 @@ namespace Unity.Netcode
         /// <param name="oneByteChars">Whether or not to use one byte per character. This will only allow ASCII</param>
         public unsafe void WriteValue(string s, bool oneByteChars = false)
         {
-            WriteValue((uint)s.Length);
+            WriteLength((uint)s.Length);
             int target = s.Length;
             if (oneByteChars)
             {
@@ -538,7 +538,7 @@ namespace Unity.Netcode
                 throw new OverflowException("Writing past the end of the buffer");
             }
 
-            WriteValue((uint)s.Length);
+            WriteLength((uint)s.Length);
             int target = s.Length;
             if (oneByteChars)
             {
@@ -569,7 +569,7 @@ namespace Unity.Netcode
         {
             int sizeInTs = count != -1 ? count : array.Length - offset;
             int sizeInBytes = sizeInTs * sizeof(T);
-            return sizeof(int) + sizeInBytes;
+            return SizeOfLengthField() + sizeInBytes;
         }
 
         /// <summary>
@@ -585,7 +585,7 @@ namespace Unity.Netcode
         {
             int sizeInTs = count != -1 ? count : array.Length - offset;
             int sizeInBytes = sizeInTs * sizeof(T);
-            return sizeof(int) + sizeInBytes;
+            return SizeOfLengthField() + sizeInBytes;
         }
 
 #if UNITY_NETCODE_NATIVE_COLLECTION_SUPPORT
@@ -602,7 +602,7 @@ namespace Unity.Netcode
         {
             int sizeInTs = count != -1 ? count : array.Length - offset;
             int sizeInBytes = sizeInTs * sizeof(T);
-            return sizeof(int) + sizeInBytes;
+            return SizeOfLengthField() + sizeInBytes;
         }
 #endif
 
@@ -876,7 +876,7 @@ namespace Unity.Netcode
         public static int GetWriteSize<T>(in T value)
             where T : unmanaged, INativeList<byte>, IUTF8Bytes
         {
-            return value.Length + sizeof(int);
+            return SizeOfLengthField() + value.Length;
         }
 
         /// <summary>
@@ -888,10 +888,10 @@ namespace Unity.Netcode
         public static int GetWriteSize<T>(in NativeArray<T> value)
             where T : unmanaged, INativeList<byte>, IUTF8Bytes
         {
-            var size = sizeof(int);
+            var size = SizeOfLengthField();
             foreach (var item in value)
             {
-                size += sizeof(int) + item.Length;
+                size += SizeOfLengthField() + item.Length;
             }
 
             return size;
@@ -907,10 +907,10 @@ namespace Unity.Netcode
         public static int GetWriteSize<T>(in NativeList<T> value)
             where T : unmanaged, INativeList<byte>, IUTF8Bytes
         {
-            var size = sizeof(int);
+            var size = SizeOfLengthField();
             foreach (var item in value)
             {
-                size += sizeof(int) + item.Length;
+                size += SizeOfLengthField() + item.Length;
             }
 
             return size;
@@ -946,10 +946,32 @@ namespace Unity.Netcode
             }
         }
 
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private static int SizeOfLengthField() => sizeof(uint);
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private void WriteLengthSafe(uint length) => WriteUnmanagedSafe(length);
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private void WriteLength(uint length) => WriteUnmanaged(length);
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private void WriteLengthSafe(int length)
+        {
+            if (length < 0)
+            {
+                throw new InvalidCastException("Cannot write negative length");
+            }
+            WriteLengthSafe((uint)length);
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private void WriteLength(int length) => WriteLength((uint)length);
+
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         internal unsafe void WriteUnmanaged<T>(T[] value) where T : unmanaged
         {
-            WriteUnmanaged(value.Length);
+            WriteLength(value.Length);
             fixed (T* ptr = value)
             {
                 byte* bytes = (byte*)ptr;
@@ -959,7 +981,7 @@ namespace Unity.Netcode
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         internal unsafe void WriteUnmanagedSafe<T>(T[] value) where T : unmanaged
         {
-            WriteUnmanagedSafe(value.Length);
+            WriteLengthSafe(value.Length);
             fixed (T* ptr = value)
             {
                 byte* bytes = (byte*)ptr;
@@ -970,7 +992,7 @@ namespace Unity.Netcode
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         internal unsafe void WriteUnmanaged<T>(NativeArray<T> value) where T : unmanaged
         {
-            WriteUnmanaged(value.Length);
+            WriteLength(value.Length);
             var ptr = (T*)value.GetUnsafePtr();
             {
                 byte* bytes = (byte*)ptr;
@@ -980,7 +1002,7 @@ namespace Unity.Netcode
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         internal unsafe void WriteUnmanagedSafe<T>(NativeArray<T> value) where T : unmanaged
         {
-            WriteUnmanagedSafe(value.Length);
+            WriteLengthSafe(value.Length);
             var ptr = (T*)value.GetUnsafePtr();
             {
                 byte* bytes = (byte*)ptr;
@@ -992,7 +1014,7 @@ namespace Unity.Netcode
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         internal unsafe void WriteUnmanaged<T>(NativeList<T> value) where T : unmanaged
         {
-            WriteUnmanaged(value.Length);
+            WriteLength(value.Length);
 #if UTP_TRANSPORT_2_0_ABOVE
             var ptr = value.GetUnsafePtr();
 #else
@@ -1006,7 +1028,7 @@ namespace Unity.Netcode
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         internal unsafe void WriteUnmanagedSafe<T>(NativeList<T> value) where T : unmanaged
         {
-            WriteUnmanagedSafe(value.Length);
+            WriteLengthSafe(value.Length);
 #if UTP_TRANSPORT_2_0_ABOVE
             var ptr = value.GetUnsafePtr();
 #else
@@ -1210,9 +1232,9 @@ namespace Unity.Netcode
         internal void WriteValueSafe<T>(NativeHashSet<T> value) where T : unmanaged, IEquatable<T>
         {
 #if UTP_TRANSPORT_2_0_ABOVE
-            WriteUnmanagedSafe(value.Count);
+            WriteLengthSafe(value.Count);
 #else
-            WriteUnmanagedSafe(value.Count());
+            WriteLengthSafe(value.Count());
 #endif
             foreach (var item in value)
             {
@@ -1227,9 +1249,9 @@ namespace Unity.Netcode
             where TVal : unmanaged
         {
 #if UTP_TRANSPORT_2_0_ABOVE
-            WriteUnmanagedSafe(value.Count);
+            WriteLengthSafe(value.Count);
 #else
-            WriteUnmanagedSafe(value.Count());
+            WriteLengthSafe(value.Count());
 #endif
             foreach (var item in value)
             {
@@ -1765,7 +1787,8 @@ namespace Unity.Netcode
         public unsafe void WriteValue<T>(in T value, ForFixedStrings unused = default)
             where T : unmanaged, INativeList<byte>, IUTF8Bytes
         {
-            WriteUnmanaged(value.Length);
+            // BytePacker.WriteValuePacked(this, value.Length);
+            WriteLength(value.Length);
             // This avoids a copy on the string, which could be costly for FixedString4096Bytes
             // Otherwise, GetUnsafePtr() is an impure function call and will result in a copy
             // for `in` parameters.
@@ -1787,7 +1810,7 @@ namespace Unity.Netcode
         public void WriteValue<T>(T[] value, ForFixedStrings unused = default)
             where T : unmanaged, INativeList<byte>, IUTF8Bytes
         {
-            WriteUnmanaged(value.Length);
+            WriteLength(value.Length);
             foreach (var str in value)
             {
                 WriteValue(str);
@@ -1806,7 +1829,7 @@ namespace Unity.Netcode
         public void WriteValue<T>(in NativeArray<T> value, ForFixedStrings unused = default)
             where T : unmanaged, INativeList<byte>, IUTF8Bytes
         {
-            WriteUnmanaged(value.Length);
+            WriteLength(value.Length);
             foreach (var str in value)
             {
                 WriteValue(str);
@@ -1826,7 +1849,7 @@ namespace Unity.Netcode
         public void WriteValue<T>(in NativeList<T> value, ForFixedStrings unused = default)
             where T : unmanaged, INativeList<byte>, IUTF8Bytes
         {
-            WriteUnmanaged(value.Length);
+            WriteLength(value.Length);
             foreach (var str in value)
             {
                 WriteValue(str);
@@ -1848,7 +1871,7 @@ namespace Unity.Netcode
         public void WriteValueSafe<T>(in T value, ForFixedStrings unused = default)
             where T : unmanaged, INativeList<byte>, IUTF8Bytes
         {
-            if (!TryBeginWriteInternal(sizeof(int) + value.Length))
+            if (!TryBeginWriteInternal(SizeOfLengthField() + value.Length))
             {
                 throw new OverflowException("Writing past the end of the buffer");
             }
@@ -1871,7 +1894,7 @@ namespace Unity.Netcode
             {
                 throw new OverflowException("Writing past the end of the buffer");
             }
-            WriteUnmanaged(value.Length);
+            WriteLength(value.Length);
             foreach (var str in value)
             {
                 WriteValue(str);
@@ -1894,7 +1917,7 @@ namespace Unity.Netcode
             {
                 throw new OverflowException("Writing past the end of the buffer");
             }
-            WriteUnmanaged(value.Length);
+            WriteLength(value.Length);
             foreach (var str in value)
             {
                 WriteValue(str);
@@ -1918,7 +1941,7 @@ namespace Unity.Netcode
             {
                 throw new OverflowException("Writing past the end of the buffer");
             }
-            WriteUnmanaged(value.Length);
+            WriteLength(value.Length);
             foreach (var str in value)
             {
                 WriteValue(str);

Runtime/Spawning/NetworkSpawnManager.cs

@@ -275,17 +275,17 @@ namespace Unity.Netcode
         }
 
         /// <summary>
-        /// Returns a list of all NetworkObjects that belong to a client.
+        /// Returns an array of all NetworkObjects that belong to a client.
         /// </summary>
-        /// <param name="clientId">the client's id  <see cref="NetworkManager.LocalClientId"/></param>
-        /// <returns>returns the list of <see cref="NetworkObject"/>s owned by the client</returns>
-        public List<NetworkObject> GetClientOwnedObjects(ulong clientId)
+        /// <param name="clientId">the client's id <see cref="NetworkManager.LocalClientId"/></param>
+        /// <returns>returns an array of the <see cref="NetworkObject"/>s owned by the client</returns>
+        public NetworkObject[] GetClientOwnedObjects(ulong clientId)
         {
             if (!OwnershipToObjectsTable.ContainsKey(clientId))
             {
                 OwnershipToObjectsTable.Add(clientId, new Dictionary<ulong, NetworkObject>());
             }
-            return OwnershipToObjectsTable[clientId].Values.ToList();
+            return OwnershipToObjectsTable[clientId].Values.ToArray();
         }
 
         /// <summary>

Runtime/Transports/NetworkTransport.cs

@@ -106,6 +106,22 @@ namespace Unity.Netcode
         /// </summary>
         /// /// <param name="networkManager">optionally pass in NetworkManager</param>
         public abstract void Initialize(NetworkManager networkManager = null);
+
+        protected virtual NetworkTopologyTypes OnCurrentTopology()
+        {
+            return NetworkTopologyTypes.ClientServer;
+        }
+
+        internal NetworkTopologyTypes CurrentTopology()
+        {
+            return OnCurrentTopology();
+        }
+    }
+
+    public enum NetworkTopologyTypes
+    {
+        ClientServer,
+        DistributedAuthority
     }
 
 #if UNITY_INCLUDE_TESTS

Runtime/Transports/UTP/UnityTransport.cs

@@ -1477,6 +1477,11 @@ namespace Unity.Netcode.Transports.UTP
         }
 #endif
 
+        protected override NetworkTopologyTypes OnCurrentTopology()
+        {
+            return NetworkManager != null ? NetworkManager.NetworkConfig.NetworkTopology : NetworkTopologyTypes.ClientServer;
+        }
+
         private string m_ServerPrivateKey;
         private string m_ServerCertificate;
 

Runtime/com.unity.netcode.runtime.asmdef

@@ -15,7 +15,13 @@
         "Unity.Burst",
         "Unity.Mathematics"
     ],
+    "includePlatforms": [],
+    "excludePlatforms": [],
     "allowUnsafeCode": true,
+    "overrideReferences": false,
+    "precompiledReferences": [],
+    "autoReferenced": true,
+    "defineConstraints": [],
     "versionDefines": [
         {
             "name": "com.unity.multiplayer.tools",
@@ -61,6 +67,12 @@
             "name": "com.unity.modules.physics2d",
             "expression": "",
             "define": "COM_UNITY_MODULES_PHYSICS2D"
+        },
+        {
+            "name": "com.unity.services.multiplayer",
+            "expression": "0.2.0",
+            "define": "MULTIPLAYER_SERVICES_SDK_INSTALLED"
         }
-    ]
-}
+    ],
+    "noEngineReferences": false
+}

TestHelpers/Runtime/MockTransport.cs

@@ -81,6 +81,11 @@ namespace Unity.Netcode.TestHelpers.Runtime
         {
         }
 
+        protected override NetworkTopologyTypes OnCurrentTopology()
+        {
+            return NetworkManager != null ? NetworkManager.NetworkConfig.NetworkTopology : NetworkTopologyTypes.ClientServer;
+        }
+
         public override void Initialize(NetworkManager networkManager = null)
         {
             NetworkManager = networkManager;

Tests/Runtime/NetworkObject/NetworkObjectDestroyTests.cs

@@ -14,6 +14,7 @@ namespace Unity.Netcode.RuntimeTests
     /// - Client destroy spawned => throw exception.
     /// </summary>
 
+
     [TestFixture(NetworkTopologyTypes.DistributedAuthority)]
     [TestFixture(NetworkTopologyTypes.ClientServer)]
     internal class NetworkObjectDestroyTests : NetcodeIntegrationTest

Tests/Runtime/NetworkObject/NetworkObjectOnSpawnTests.cs

@@ -7,6 +7,7 @@ using UnityEngine.TestTools;
 
 namespace Unity.Netcode.RuntimeTests
 {
+
     [TestFixture(NetworkTopologyTypes.DistributedAuthority)]
     [TestFixture(NetworkTopologyTypes.ClientServer)]
     internal class NetworkObjectOnSpawnTests : NetcodeIntegrationTest

Tests/Runtime/NetworkObject/NetworkObjectOwnershipPropertiesTests.cs

@@ -8,6 +8,7 @@ using UnityEngine.TestTools;
 
 namespace Unity.Netcode.RuntimeTests
 {
+
     [TestFixture(NetworkTopologyTypes.DistributedAuthority)]
     [TestFixture(NetworkTopologyTypes.ClientServer)]
     internal class NetworkObjectOwnershipPropertiesTests : NetcodeIntegrationTest

Tests/Runtime/NetworkObject/NetworkObjectOwnershipTests.cs

@@ -358,7 +358,7 @@ namespace Unity.Netcode.RuntimeTests
 
             foreach (var clientNetworkManager in m_ClientNetworkManagers)
             {
-                if (clientNetworkManager.LocalClient.OwnedObjects.Count < k_NumberOfSpawnedObjects)
+                if (clientNetworkManager.LocalClient.OwnedObjects.Length < k_NumberOfSpawnedObjects)
                 {
                     return false;
                 }
@@ -372,7 +372,7 @@ namespace Unity.Netcode.RuntimeTests
             // Only check when we are the host
             if (m_ServerNetworkManager.IsHost)
             {
-                if (m_ServerNetworkManager.LocalClient.OwnedObjects.Count < k_NumberOfSpawnedObjects)
+                if (m_ServerNetworkManager.LocalClient.OwnedObjects.Length < k_NumberOfSpawnedObjects)
                 {
                     return false;
                 }
@@ -380,7 +380,7 @@ namespace Unity.Netcode.RuntimeTests
 
             foreach (var connectedClient in m_ServerNetworkManager.ConnectedClients)
             {
-                if (connectedClient.Value.OwnedObjects.Count < k_NumberOfSpawnedObjects)
+                if (connectedClient.Value.OwnedObjects.Length < k_NumberOfSpawnedObjects)
                 {
                     return false;
                 }

package.json

@@ -2,23 +2,23 @@
   "name": "com.unity.netcode.gameobjects",
   "displayName": "Netcode for GameObjects",
   "description": "Netcode for GameObjects is a high-level netcode SDK that provides networking capabilities to GameObject/MonoBehaviour workflows within Unity and sits on top of underlying transport layer.",
-  "version": "2.0.0-exp.4",
+  "version": "2.0.0-pre.1",
   "unity": "6000.0",
   "dependencies": {
     "com.unity.nuget.mono-cecil": "1.11.4",
     "com.unity.transport": "2.2.1"
   },
   "_upm": {
-    "changelog": "### Added\n\n- Added `NetworkRigidbodyBase.AttachToFixedJoint` and `NetworkRigidbodyBase.DetachFromFixedJoint` to replace parenting for rigid bodies that have `NetworkRigidbodyBase.UseRigidBodyForMotion` enabled. (#2933)\n- Added `NetworkBehaviour.OnNetworkPreSpawn` and `NetworkBehaviour.OnNetworkPostSpawn` methods that provide the ability to handle pre and post spawning actions during the `NetworkObject` spawn sequence. (#2912)\n- Added a client-side only `NetworkBehaviour.OnNetworkSessionSynchronized` convenience method that is invoked on all `NetworkBehaviour`s after a newly joined client has finished synchronizing with the network session in progress. (#2912)\n- Added `NetworkBehaviour.OnInSceneObjectsSpawned` convenience method that is invoked when all in-scene `NetworkObject`s have been spawned after a scene has been loaded or upon a host or server starting. (#2912)\n\n### Fixed\n\n- Fixed issue where non-authoritative rigid bodies with `NetworkRigidbodyBase.UseRigidBodyForMotion` enabled would constantly log errors about the renderTime being before `StartTimeConsumed`. (#2933)\n- Fixed issue where in-scene placed NetworkObjects could be destroyed if a client disconnects early and/or before approval. (#2924)\n- Fixed issue where a `NetworkObject` component's associated `NetworkBehaviour` components would not be detected if scene loading is disabled in the editor and the currently loaded scene has in-scene placed `NetworkObject`s. (#2912)\n- Fixed issue where an in-scene placed `NetworkObject` with `NetworkTransform` that is also parented under a `GameObject` would not properly synchronize when the parent `GameObject` had a world space position other than 0,0,0. (#2898)\n\n### Changed\n\n- Change all the access modifiers of test class from Public to Internal (#2930)\n- Changed messages are now sorted by enum values as opposed to ordinally sorting the messages by their type name. (#2929)\n- Changed `NetworkClient.SessionModeTypes` to `NetworkClient.NetworkTopologyTypes`. (#2875)\n- Changed `NetworkClient.SessionModeType` to `NetworkClient.NetworkTopologyType`. (#2875)\n- Changed `NetworkConfig.SessionMode` to `NeworkConfig.NetworkTopology`. (#2875)"
+    "changelog": "### Added\n\n- Added event `NetworkManager.OnSessionOwnerPromoted` that is invoked when a new session owner promotion occurs. (#2948)\n- Added `NetworkRigidBodyBase.GetLinearVelocity` and `NetworkRigidBodyBase.SetLinearVelocity` convenience/helper methods. (#2948)\n- Added `NetworkRigidBodyBase.GetAngularVelocity` and `NetworkRigidBodyBase.SetAngularVelocity` convenience/helper methods. (#2948)\n\n### Fixed\n\n- Fixed issue when `NetworkTransform` half float precision is enabled and ownership changes the current base position was not being synchronized. (#2948)\n- Fixed issue where `OnClientConnected` not being invoked on the session owner when connecting to a new distributed authority session. (#2948)\n- Fixed issue where Rigidbody micro-motion (i.e. relatively small velocities) would result in non-authority instances slightly stuttering as the body would come to a rest (i.e. no motion). Now, the threshold value can increase at higher velocities and can decrease slightly below the provided threshold to account for this. (#2948)\n\n### Changed\n\n- Changed the client's owned objects is now returned (`NetworkClient` and `NetworkSpawnManager`) as an array as opposed to a list for performance purposes. (#2948)\n- Changed `NetworkTransfrom.TryCommitTransformToServer` to be internal as it will be removed by the final 2.0.0 release. (#2948)\n- Changed `NetworkTransformEditor.OnEnable` to a virtual method to be able to customize a `NetworkTransform` derived class by creating a derived editor control from `NetworkTransformEditor`. (#2948)"
   },
   "upmCi": {
-    "footprint": "3e5693a7baed1b97a205035203bc4da81af55612"
+    "footprint": "18101c69b1634ca6a71617efbaf53473b389e8ec"
   },
   "documentationUrl": "https://docs.unity3d.com/Packages/com.unity.netcode.gameobjects@2.0/manual/index.html",
   "repository": {
     "url": "https://github.com/Unity-Technologies/com.unity.netcode.gameobjects.git",
     "type": "git",
-    "revision": "f4917e9cb719980bf229a71484d6f5467a2ad4e0"
+    "revision": "ba4102f8ded1ed3f18c5b0604bd39a846437e9b6"
   },
   "samples": [
     {