com.unity.netcode.gameobjects@2.1.1

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).

## [2.1.1] - 2024-10-18

### Added

- Added ability to edit the `NetworkConfig.AutoSpawnPlayerPrefabClientSide` within the inspector view. (#3097)
- Added `IContactEventHandlerWithInfo` that derives from `IContactEventHandler` that can be updated per frame to provide `ContactEventHandlerInfo` information to the `RigidbodyContactEventManager` when processing collisions. (#3094)
  - `ContactEventHandlerInfo.ProvideNonRigidBodyContactEvents`: When set to true, non-`Rigidbody` collisions with the registered `Rigidbody` will generate contact event notifications. (#3094)
  - `ContactEventHandlerInfo.HasContactEventPriority`: When set to true, the `Rigidbody` will be prioritized as the instance that generates the event if the `Rigidbody` colliding does not have priority. (#3094)
- Added a static `NetworkManager.OnInstantiated` event notification to be able to track when a new `NetworkManager` instance has been instantiated. (#3088)
- Added a static `NetworkManager.OnDestroying` event notification to be able to track when an existing `NetworkManager` instance is being destroyed. (#3088)

### Fixed

- Fixed issue where `NetworkPrefabProcessor` would not mark the prefab list as dirty and prevent saving the `DefaultNetworkPrefabs` asset when only imports or only deletes were detected.(#3103)
- Fixed an issue where nested `NetworkTransform` components in owner authoritative mode cleared their initial settings on the server, causing improper synchronization. (#3099)
- Fixed issue with service not getting synchronized with in-scene placed `NetworkObject` instances when a session owner starts a `SceneEventType.Load` event. (#3096)
- Fixed issue with the in-scene network prefab instance update menu tool where it was not properly updating scenes when invoked on the root prefab instance. (#3092)
- Fixed an issue where newly synchronizing clients would always receive current `NetworkVariable` values, potentially causing issues with collections if there were pending updates. Now, pending state updates serialize previous values to avoid duplicates on new clients. (#3081)
- Fixed issue where changing ownership would mark every `NetworkVariable` dirty. Now, it will only mark any `NetworkVariable` with owner read permissions as dirty and will send/flush any pending updates to all clients prior to sending the change in ownership message. (#3081)
- Fixed an issue where transferring ownership of `NetworkVariable` collections didn't update the new owner’s previous value, causing the last added value to be detected as a change during additions or removals. (#3081)
- Fixed issue where a client (or server) with no write permissions for a `NetworkVariable` using a standard .NET collection type could still modify the collection which could cause various issues depending upon the modification and collection type. (#3081)
- Fixed issue where applying the position and/or rotation to the `NetworkManager.ConnectionApprovalResponse` when connection approval and auto-spawn player prefab were enabled would not apply the position and/or rotation when the player prefab was instantiated. (#3078)
- Fixed issue where `NetworkObject.SpawnWithObservers` was not being honored when spawning the player prefab. (#3077)
- Fixed issue with the client count not being correct on the host or server side when a client disconnects itself from a session. (#3075)

### Changed

- Changed `NetworkConfig.AutoSpawnPlayerPrefabClientSide` is no longer automatically set when starting `NetworkManager`. (#3097)
- Updated `NetworkVariableDeltaMessage` so the server now forwards delta state updates from clients immediately, instead of waiting until the end of the frame or the next network tick. (#3081)

Runtime/Components/NetworkTransform.cs

@@ -1463,8 +1463,6 @@ namespace Unity.Netcode.Components
         // For test logging purposes
         internal NetworkTransformState SynchronizeState;
 
-        // DANGO-TODO: We will want to remove this when we migrate NetworkTransforms to a dedicated internal message
-        private const ushort k_NetworkTransformStateMagic = 0xf48d;
         #endregion
 
         #region ONSYNCHRONIZE
@@ -1489,19 +1487,10 @@ namespace Unity.Netcode.Components
                 HalfVectorRotation = new HalfVector4(),
                 HalfVectorScale = new HalfVector3(),
                 NetworkDeltaPosition = new NetworkDeltaPosition(),
-
             };
 
             if (serializer.IsWriter)
             {
-                // DANGO-TODO: This magic value is sent to the server in order to identify the network transform.
-                // The server discards it before forwarding synchronization data to other clients.
-                if (NetworkManager.DistributedAuthorityMode && NetworkManager.CMBServiceConnection)
-                {
-                    var writer = serializer.GetFastBufferWriter();
-                    writer.WriteValueSafe(k_NetworkTransformStateMagic);
-                }
-
                 SynchronizeState.IsTeleportingNextFrame = true;
                 var transformToCommit = transform;
                 // If we are using Half Float Precision, then we want to only synchronize the authority's m_HalfPositionState.FullPosition in order for
@@ -3060,12 +3049,44 @@ namespace Unity.Netcode.Components
             base.InternalOnNetworkSessionSynchronized();
         }
 
+        private void ApplyPlayerTransformState()
+        {
+            SynchronizeState.InLocalSpace = InLocalSpace;
+            SynchronizeState.UseInterpolation = Interpolate;
+            SynchronizeState.QuaternionSync = UseQuaternionSynchronization;
+            SynchronizeState.UseHalfFloatPrecision = UseHalfFloatPrecision;
+            SynchronizeState.QuaternionCompression = UseQuaternionCompression;
+            SynchronizeState.UsePositionSlerp = SlerpPosition;
+        }
+
         /// <summary>
         /// For dynamically spawned NetworkObjects, when the non-authority instance's client is already connected and
         /// the SynchronizeState is still pending synchronization then we want to finalize the synchornization at this time.
         /// </summary>
         protected internal override void InternalOnNetworkPostSpawn()
         {
+            // This is a special case for client-server where a server is spawning an owner authoritative NetworkObject but has yet to serialize anything.
+            // When the server detects that:
+            // - We are not in a distributed authority session (DAHost check).
+            // - This is the first/root NetworkTransform.
+            // - We are in owner authoritative mode.
+            // - The NetworkObject is not owned by the server.
+            // - The SynchronizeState.IsSynchronizing is set to false.
+            // Then we want to:
+            // - Force the "IsSynchronizing" flag so the NetworkTransform has its state updated properly and runs through the initialization again.
+            // - Make sure the SynchronizingState is updated to the instantiated prefab's default flags/settings.
+            if (NetworkManager.IsServer && !NetworkManager.DistributedAuthorityMode && m_IsFirstNetworkTransform && !OnIsServerAuthoritative() && !IsOwner && !SynchronizeState.IsSynchronizing)
+            {
+                // Assure the first/root NetworkTransform has the synchronizing flag set so the server runs through the final post initialization steps
+                SynchronizeState.IsSynchronizing = true;
+                // Assure the SynchronizeState matches the initial prefab's values for each associated NetworkTransfrom (this includes root + all children)
+                foreach (var child in NetworkObject.NetworkTransforms)
+                {
+                    child.ApplyPlayerTransformState();
+                }
+                // Now fall through to the final synchronization portion of the spawning for NetworkTransform
+            }
+
             if (!CanCommitToTransform && NetworkManager.IsConnectedClient && SynchronizeState.IsSynchronizing)
             {
                 NonAuthorityFinalizeSynchronization();

Runtime/Components/RigidbodyContactEventManager.cs

@@ -6,13 +6,70 @@ using UnityEngine;
 
 namespace Unity.Netcode.Components
 {
+    /// <summary>
+    /// Information a <see cref="Rigidbody"/> returns to <see cref="RigidbodyContactEventManager"/> via <see cref="IContactEventHandlerWithInfo.GetContactEventHandlerInfo"/> <br />
+    /// if the <see cref="Rigidbody"/> registers itself with <see cref="IContactEventHandlerWithInfo"/> as opposed to <see cref="IContactEventHandler"/>.
+    /// </summary>
+    public struct ContactEventHandlerInfo
+    {
+        /// <summary>
+        /// When set to true, the <see cref="RigidbodyContactEventManager"/> will include non-Rigidbody based contact events.<br />
+        /// When the <see cref="RigidbodyContactEventManager"/> invokes the <see cref="IContactEventHandler.ContactEvent"/> it will return null in place <br />
+        /// of the collidingBody parameter if the contact event occurred with a collider that is not registered with the <see cref="RigidbodyContactEventManager"/>.
+        /// </summary>
+        public bool ProvideNonRigidBodyContactEvents;
+        /// <summary>
+        /// When set to true, the <see cref="RigidbodyContactEventManager"/> will prioritize invoking <see cref="IContactEventHandler.ContactEvent(ulong, Vector3, Rigidbody, Vector3, bool, Vector3)"/> <br /></br>
+        /// if it is the 2nd colliding body in the contact pair being processed. With distributed authority, setting this value to true when a <see cref="NetworkObject"/> is owned by the local client <br />
+        /// will assure <see cref="IContactEventHandler.ContactEvent(ulong, Vector3, Rigidbody, Vector3, bool, Vector3)"/> is only invoked on the authoritative side.
+        /// </summary>
+        public bool HasContactEventPriority;
+    }
+
+    /// <summary>
+    /// Default implementation required to register a <see cref="Rigidbody"/> with a <see cref="RigidbodyContactEventManager"/> instance. 
+    /// </summary>
+    /// <remarks>
+    /// Recommended to implement this method on a <see cref="NetworkBehaviour"/> component
+    /// </remarks>
     public interface IContactEventHandler
     {
+        /// <summary>
+        /// Should return a <see cref="Rigidbody"/>.
+        /// </summary>
         Rigidbody GetRigidbody();
 
+        /// <summary>
+        /// Invoked by the <see cref="RigidbodyContactEventManager"/> instance.
+        /// </summary>
+        /// <param name="eventId">A unique contact event identifier.</param>
+        /// <param name="averagedCollisionNormal">The average normal of the collision between two colliders.</param>
+        /// <param name="collidingBody">If not null, this will be a registered <see cref="Rigidbody"/> that was part of the collision contact event.</param>
+        /// <param name="contactPoint">The world space location of the contact event.</param>
+        /// <param name="hasCollisionStay">Will be set if this is a collision stay contact event (i.e. it is not the first contact event and continually has contact)</param>
+        /// <param name="averagedCollisionStayNormal">The average normal of the collision stay contact over time.</param>
         void ContactEvent(ulong eventId, Vector3 averagedCollisionNormal, Rigidbody collidingBody, Vector3 contactPoint, bool hasCollisionStay = false, Vector3 averagedCollisionStayNormal = default);
     }
 
+    /// <summary>
+    /// This is an extended version of <see cref="IContactEventHandler"/> and can be used to register a <see cref="Rigidbody"/> with a <see cref="RigidbodyContactEventManager"/> instance. <br />
+    /// This provides additional <see cref="ContactEventHandlerInfo"/> information to the <see cref="RigidbodyContactEventManager"/> for each set of contact events it is processing.
+    /// </summary>
+    public interface IContactEventHandlerWithInfo : IContactEventHandler
+    {
+        /// <summary>
+        /// Invoked by <see cref="RigidbodyContactEventManager"/> for each set of contact events it is processing (prior to processing).
+        /// </summary>
+        /// <returns><see cref="ContactEventHandlerInfo"/></returns>
+        ContactEventHandlerInfo GetContactEventHandlerInfo();
+    }
+
+    /// <summary>
+    /// Add this component to an in-scene placed GameObject to provide faster collision event processing between <see cref="Rigidbody"/> instances and optionally static colliders.
+    /// <see cref="IContactEventHandler"/> <br />
+    /// <see cref="IContactEventHandlerWithInfo"/> <br />
+    /// <see cref="ContactEventHandlerInfo"/> <br />
+    /// </summary>
     [AddComponentMenu("Netcode/Rigidbody Contact Event Manager")]
     public class RigidbodyContactEventManager : MonoBehaviour
     {
@@ -34,6 +91,7 @@ namespace Unity.Netcode.Components
 
         private readonly Dictionary<int, Rigidbody> m_RigidbodyMapping = new Dictionary<int, Rigidbody>();
         private readonly Dictionary<int, IContactEventHandler> m_HandlerMapping = new Dictionary<int, IContactEventHandler>();
+        private readonly Dictionary<int, ContactEventHandlerInfo> m_HandlerInfo = new Dictionary<int, ContactEventHandlerInfo>();
 
         private void OnEnable()
         {
@@ -49,6 +107,15 @@ namespace Unity.Netcode.Components
             Instance = this;
         }
 
+        /// <summary>
+        /// Any <see cref="IContactEventHandler"/> implementation can register a <see cref="Rigidbody"/> to be handled by this <see cref="RigidbodyContactEventManager"/> instance.
+        /// </summary>
+        /// <remarks>
+        /// You should enable <see cref="Collider.providesContacts"/> for each <see cref="Collider"/> associated with the <see cref="Rigidbody"/> being registered.<br/>
+        /// You can enable this during run time or within the editor's inspector view.
+        /// </remarks>
+        /// <param name="contactEventHandler"><see cref="IContactEventHandler"/> or <see cref="IContactEventHandlerWithInfo"/></param>
+        /// <param name="register">true to register and false to remove from being registered</param>
         public void RegisterHandler(IContactEventHandler contactEventHandler, bool register = true)
         {
             var rigidbody = contactEventHandler.GetRigidbody();
@@ -64,6 +131,22 @@ namespace Unity.Netcode.Components
                 {
                     m_HandlerMapping.Add(instanceId, contactEventHandler);
                 }
+
+                if (!m_HandlerInfo.ContainsKey(instanceId))
+                {
+                    var handlerInfo = new ContactEventHandlerInfo()
+                    {
+                        HasContactEventPriority = true,
+                        ProvideNonRigidBodyContactEvents = false,
+                    };
+                    var handlerWithInfo = contactEventHandler as IContactEventHandlerWithInfo;
+
+                    if (handlerWithInfo != null)
+                    {
+                        handlerInfo = handlerWithInfo.GetContactEventHandlerInfo();
+                    }
+                    m_HandlerInfo.Add(instanceId, handlerInfo);
+                }
             }
             else
             {
@@ -88,25 +171,98 @@ namespace Unity.Netcode.Components
 
         private void ProcessCollisions()
         {
+            foreach (var contactEventHandler in m_HandlerMapping)
+            {
+                var handlerWithInfo = contactEventHandler.Value as IContactEventHandlerWithInfo;
+
+                if (handlerWithInfo != null)
+                {
+                    m_HandlerInfo[contactEventHandler.Key] = handlerWithInfo.GetContactEventHandlerInfo();
+                }
+                else
+                {
+                    var info = m_HandlerInfo[contactEventHandler.Key];
+                    info.HasContactEventPriority = !m_RigidbodyMapping[contactEventHandler.Key].isKinematic;
+                    m_HandlerInfo[contactEventHandler.Key] = info;
+                }
+            }
+
+            ContactEventHandlerInfo contactEventHandlerInfo0;
+            ContactEventHandlerInfo contactEventHandlerInfo1;
+
             // Process all collisions
             for (int i = 0; i < m_Count; i++)
             {
                 var thisInstanceID = m_ResultsArray[i].ThisInstanceID;
                 var otherInstanceID = m_ResultsArray[i].OtherInstanceID;
-                var rb0Valid = thisInstanceID != 0 && m_RigidbodyMapping.ContainsKey(thisInstanceID);
-                var rb1Valid = otherInstanceID != 0 && m_RigidbodyMapping.ContainsKey(otherInstanceID);
-                // Only notify registered rigid bodies.
-                if (!rb0Valid || !rb1Valid || !m_HandlerMapping.ContainsKey(thisInstanceID))
+                var contactHandler0 = (IContactEventHandler)null;
+                var contactHandler1 = (IContactEventHandler)null;
+                var preferredContactHandler = (IContactEventHandler)null;
+                var preferredContactHandlerNonRigidbody = false;
+                var preferredRigidbody = (Rigidbody)null;
+                var otherContactHandler = (IContactEventHandler)null;
+                var otherRigidbody = (Rigidbody)null;
+
+                var otherContactHandlerNonRigidbody = false;
+
+                if (m_RigidbodyMapping.ContainsKey(thisInstanceID))
+                {
+                    contactHandler0 = m_HandlerMapping[thisInstanceID];
+                    contactEventHandlerInfo0 = m_HandlerInfo[thisInstanceID];
+                    if (contactEventHandlerInfo0.HasContactEventPriority)
+                    {
+                        preferredContactHandler = contactHandler0;
+                        preferredContactHandlerNonRigidbody = contactEventHandlerInfo0.ProvideNonRigidBodyContactEvents;
+                        preferredRigidbody = m_RigidbodyMapping[thisInstanceID];
+                    }
+                    else
+                    {
+                        otherContactHandler = contactHandler0;
+                        otherContactHandlerNonRigidbody = contactEventHandlerInfo0.ProvideNonRigidBodyContactEvents;
+                        otherRigidbody = m_RigidbodyMapping[thisInstanceID];
+                    }
+                }
+
+                if (m_RigidbodyMapping.ContainsKey(otherInstanceID))
+                {
+                    contactHandler1 = m_HandlerMapping[otherInstanceID];
+                    contactEventHandlerInfo1 = m_HandlerInfo[otherInstanceID];
+                    if (contactEventHandlerInfo1.HasContactEventPriority && preferredContactHandler == null)
+                    {
+                        preferredContactHandler = contactHandler1;
+                        preferredContactHandlerNonRigidbody = contactEventHandlerInfo1.ProvideNonRigidBodyContactEvents;
+                        preferredRigidbody = m_RigidbodyMapping[otherInstanceID];
+                    }
+                    else
+                    {
+                        otherContactHandler = contactHandler1;
+                        otherContactHandlerNonRigidbody = contactEventHandlerInfo1.ProvideNonRigidBodyContactEvents;
+                        otherRigidbody = m_RigidbodyMapping[otherInstanceID];
+                    }
+                }
+
+                if (preferredContactHandler == null && otherContactHandler != null)
+                {
+                    preferredContactHandler = otherContactHandler;
+                    preferredContactHandlerNonRigidbody = otherContactHandlerNonRigidbody;
+                    preferredRigidbody = otherRigidbody;
+                    otherContactHandler = null;
+                    otherContactHandlerNonRigidbody = false;
+                    otherRigidbody = null;
+                }
+
+                if (preferredContactHandler == null || (preferredContactHandler != null && otherContactHandler == null && !preferredContactHandlerNonRigidbody))
                 {
                     continue;
                 }
+
                 if (m_ResultsArray[i].HasCollisionStay)
                 {
-                    m_HandlerMapping[thisInstanceID].ContactEvent(m_EventId, m_ResultsArray[i].AverageNormal, m_RigidbodyMapping[otherInstanceID], m_ResultsArray[i].ContactPoint, m_ResultsArray[i].HasCollisionStay, m_ResultsArray[i].AverageCollisionStayNormal);
+                    preferredContactHandler.ContactEvent(m_EventId, m_ResultsArray[i].AverageNormal, otherRigidbody, m_ResultsArray[i].ContactPoint, m_ResultsArray[i].HasCollisionStay, m_ResultsArray[i].AverageCollisionStayNormal);
                 }
                 else
                 {
-                    m_HandlerMapping[thisInstanceID].ContactEvent(m_EventId, m_ResultsArray[i].AverageNormal, m_RigidbodyMapping[otherInstanceID], m_ResultsArray[i].ContactPoint);
+                    preferredContactHandler.ContactEvent(m_EventId, m_ResultsArray[i].AverageNormal, otherRigidbody, m_ResultsArray[i].ContactPoint);
                 }
             }
         }

Runtime/Connection/NetworkConnectionManager.cs

@@ -105,8 +105,12 @@ namespace Unity.Netcode
                         continue;
                     }
 
-                    peerClientIds[idx] = peerId;
-                    ++idx;
+                    // This assures if the server has not timed out prior to the client synchronizing that it doesn't exceed the allocated peer count.
+                    if (peerClientIds.Length > idx)
+                    {
+                        peerClientIds[idx] = peerId;
+                        ++idx;
+                    }
                 }
 
                 try
@@ -496,24 +500,32 @@ namespace Unity.Netcode
             // Process the incoming message queue so that we get everything from the server disconnecting us or, if we are the server, so we got everything from that client.
             MessageManager.ProcessIncomingMessageQueue();
 
-            InvokeOnClientDisconnectCallback(clientId);
-
-            if (LocalClient.IsHost)
-            {
-                InvokeOnPeerDisconnectedCallback(clientId);
-            }
-
             if (LocalClient.IsServer)
             {
+                // We need to process the disconnection before notifying
                 OnClientDisconnectFromServer(clientId);
+
+                // Now notify the client has disconnected
+                InvokeOnClientDisconnectCallback(clientId);
+
+                if (LocalClient.IsHost)
+                {
+                    InvokeOnPeerDisconnectedCallback(clientId);
+                }
             }
-            else // As long as we are not in the middle of a shutdown
-            if (!NetworkManager.ShutdownInProgress)
+            else
             {
-                // We must pass true here and not process any sends messages as we are no longer connected.
-                // Otherwise, attempting to process messages here can cause an exception within UnityTransport
-                // as the client ID is no longer valid.
-                NetworkManager.Shutdown(true);
+                // Notify local client of disconnection
+                InvokeOnClientDisconnectCallback(clientId);
+
+                // As long as we are not in the middle of a shutdown
+                if (!NetworkManager.ShutdownInProgress)
+                {
+                    // We must pass true here and not process any sends messages as we are no longer connected.
+                    // Otherwise, attempting to process messages here can cause an exception within UnityTransport
+                    // as the client ID is no longer valid.
+                    NetworkManager.Shutdown(true);
+                }
             }
 #if DEVELOPMENT_BUILD || UNITY_EDITOR
             s_TransportDisconnect.End();
@@ -552,9 +564,6 @@ namespace Unity.Netcode
             var message = new ConnectionRequestMessage
             {
                 CMBServiceConnection = NetworkManager.CMBServiceConnection,
-                TickRate = NetworkManager.NetworkConfig.TickRate,
-                EnableSceneManagement = NetworkManager.NetworkConfig.EnableSceneManagement,
-
                 // Since only a remote client will send a connection request, we should always force the rebuilding of the NetworkConfig hash value
                 ConfigHash = NetworkManager.NetworkConfig.GetConfig(false),
                 ShouldSendConnectionData = NetworkManager.NetworkConfig.ConnectionApproval,
@@ -562,6 +571,12 @@ namespace Unity.Netcode
                 MessageVersions = new NativeArray<MessageVersionData>(MessageManager.MessageHandlers.Length, Allocator.Temp)
             };
 
+            if (NetworkManager.CMBServiceConnection)
+            {
+                message.ClientConfig.TickRate = NetworkManager.NetworkConfig.TickRate;
+                message.ClientConfig.EnableSceneManagement = NetworkManager.NetworkConfig.EnableSceneManagement;
+            }
+
             for (int index = 0; index < MessageManager.MessageHandlers.Length; index++)
             {
                 if (MessageManager.MessageTypes[index] != null)
@@ -739,8 +754,8 @@ namespace Unity.Netcode
                 // Server-side spawning (only if there is a prefab hash or player prefab provided)
                 if (!NetworkManager.DistributedAuthorityMode && response.CreatePlayerObject && (response.PlayerPrefabHash.HasValue || NetworkManager.NetworkConfig.PlayerPrefab != null))
                 {
-                    var playerObject = response.PlayerPrefabHash.HasValue ? NetworkManager.SpawnManager.GetNetworkObjectToSpawn(response.PlayerPrefabHash.Value, ownerClientId, response.Position.GetValueOrDefault(), response.Rotation.GetValueOrDefault())
-                        : NetworkManager.SpawnManager.GetNetworkObjectToSpawn(NetworkManager.NetworkConfig.PlayerPrefab.GetComponent<NetworkObject>().GlobalObjectIdHash, ownerClientId, response.Position.GetValueOrDefault(), response.Rotation.GetValueOrDefault());
+                    var playerObject = response.PlayerPrefabHash.HasValue ? NetworkManager.SpawnManager.GetNetworkObjectToSpawn(response.PlayerPrefabHash.Value, ownerClientId, response.Position ?? null, response.Rotation ?? null)
+                    : NetworkManager.SpawnManager.GetNetworkObjectToSpawn(NetworkManager.NetworkConfig.PlayerPrefab.GetComponent<NetworkObject>().GlobalObjectIdHash, ownerClientId, response.Position ?? null, response.Rotation ?? null);
 
                     // Spawn the player NetworkObject locally
                     NetworkManager.SpawnManager.SpawnNetworkObjectLocally(
@@ -884,7 +899,7 @@ namespace Unity.Netcode
         /// <summary>
         /// Client-Side Spawning in distributed authority mode uses this to spawn the player.
         /// </summary>
-        internal void CreateAndSpawnPlayer(ulong ownerId, Vector3 position = default, Quaternion rotation = default)
+        internal void CreateAndSpawnPlayer(ulong ownerId)
         {
             if (NetworkManager.DistributedAuthorityMode && NetworkManager.AutoSpawnPlayerPrefabClientSide)
             {
@@ -892,7 +907,7 @@ namespace Unity.Netcode
                 if (playerPrefab != null)
                 {
                     var globalObjectIdHash = playerPrefab.GetComponent<NetworkObject>().GlobalObjectIdHash;
-                    var networkObject = NetworkManager.SpawnManager.GetNetworkObjectToSpawn(globalObjectIdHash, ownerId, position, rotation);
+                    var networkObject = NetworkManager.SpawnManager.GetNetworkObjectToSpawn(globalObjectIdHash, ownerId, playerPrefab.transform.position, playerPrefab.transform.rotation);
                     networkObject.IsSceneObject = false;
                     networkObject.SpawnAsPlayerObject(ownerId, networkObject.DestroyWithScene);
                 }

Runtime/Core/NetworkBehaviour.cs

@@ -826,6 +826,13 @@ namespace Unity.Netcode
         internal void InternalOnGainedOwnership()
         {
             UpdateNetworkProperties();
+            // New owners need to assure any NetworkVariables they have write permissions 
+            // to are updated so the previous and original values are aligned with the
+            // current value (primarily for collections).
+            if (OwnerClientId == NetworkManager.LocalClientId)
+            {
+                UpdateNetworkVariableOnOwnershipChanged();
+            }
             OnGainedOwnership();
         }
 
@@ -1016,9 +1023,14 @@ namespace Unity.Netcode
         internal readonly List<int> NetworkVariableIndexesToReset = new List<int>();
         internal readonly HashSet<int> NetworkVariableIndexesToResetSet = new HashSet<int>();
 
-        internal void NetworkVariableUpdate(ulong targetClientId)
+        /// <summary>
+        /// Determines if a NetworkVariable should have any changes to state sent out
+        /// </summary>
+        /// <param name="targetClientId">target to send the updates to</param>
+        /// <param name="forceSend">specific to change in ownership</param>
+        internal void NetworkVariableUpdate(ulong targetClientId, bool forceSend = false)
         {
-            if (!CouldHaveDirtyNetworkVariables())
+            if (!forceSend && !CouldHaveDirtyNetworkVariables())
             {
                 return;
             }
@@ -1069,7 +1081,11 @@ namespace Unity.Netcode
                     NetworkBehaviourIndex = behaviourIndex,
                     NetworkBehaviour = this,
                     TargetClientId = targetClientId,
-                    DeliveryMappedNetworkVariableIndex = m_DeliveryMappedNetworkVariableIndices[j]
+                    DeliveryMappedNetworkVariableIndex = m_DeliveryMappedNetworkVariableIndices[j],
+                    // By sending the network delivery we can forward messages immediately as opposed to processing them
+                    // at the end. While this will send updates to clients that cannot read, the handler will ignore anything
+                    // sent to a client that does not have read permissions.
+                    NetworkDelivery = m_DeliveryTypesForNetworkVariableGroups[j]
                 };
                 // TODO: Serialization is where the IsDirty flag gets changed.
                 // Messages don't get sent from the server to itself, so if we're host and sending to ourselves,
@@ -1114,6 +1130,26 @@ namespace Unity.Netcode
             return false;
         }
 
+        /// <summary>
+        /// Invoked on a new client to assure the previous and original values
+        /// are synchronized with the current known value.
+        /// </summary>
+        /// <remarks>
+        /// Primarily for collections to assure the previous value(s) is/are the
+        /// same as the current value(s) in order to not re-send already known entries.
+        /// </remarks>
+        internal void UpdateNetworkVariableOnOwnershipChanged()
+        {
+            for (int j = 0; j < NetworkVariableFields.Count; j++)
+            {
+                // Only invoke OnInitialize on NetworkVariables the owner can write to
+                if (NetworkVariableFields[j].CanClientWrite(OwnerClientId))
+                {
+                    NetworkVariableFields[j].OnInitialize();
+                }
+            }
+        }
+
         internal void MarkVariablesDirty(bool dirty)
         {
             for (int j = 0; j < NetworkVariableFields.Count; j++)
@@ -1122,6 +1158,17 @@ namespace Unity.Netcode
             }
         }
 
+        internal void MarkOwnerReadVariablesDirty()
+        {
+            for (int j = 0; j < NetworkVariableFields.Count; j++)
+            {
+                if (NetworkVariableFields[j].ReadPerm == NetworkVariableReadPermission.Owner)
+                {
+                    NetworkVariableFields[j].SetDirty(true);
+                }
+            }
+        }
+
         /// <summary>
         /// Synchronizes by setting only the NetworkVariable field values that the client has permission to read.
         /// Note: This is only invoked when first synchronizing a NetworkBehaviour (i.e. late join or spawned NetworkObject)
@@ -1172,17 +1219,24 @@ namespace Unity.Netcode
                         // The way we do packing, any value > 63 in a ushort will use the full 2 bytes to represent.
                         writer.WriteValueSafe((ushort)0);
                         var startPos = writer.Position;
-                        NetworkVariableFields[j].WriteField(writer);
+                        // Write the NetworkVariable field value
+                        // WriteFieldSynchronization will write the current value only if there are no pending changes.
+                        // Otherwise, it will write the previous value if there are pending changes since the pending
+                        // changes will be sent shortly after the client's synchronization.
+                        NetworkVariableFields[j].WriteFieldSynchronization(writer);
                         var size = writer.Position - startPos;
                         writer.Seek(writePos);
-                        // Write the NetworkVariable value
+                        // Write the NetworkVariable field value size
                         writer.WriteValueSafe((ushort)size);
                         writer.Seek(startPos + size);
                     }
                     else // Client-Server Only: Should only ever be invoked when using a client-server NetworkTopology
                     {
-                        // Write the NetworkVariable value
-                        NetworkVariableFields[j].WriteField(writer);
+                        // Write the NetworkVariable field value
+                        // WriteFieldSynchronization will write the current value only if there are no pending changes.
+                        // Otherwise, it will write the previous value if there are pending changes since the pending
+                        // changes will be sent shortly after the client's synchronization.
+                        NetworkVariableFields[j].WriteFieldSynchronization(writer);
                     }
                 }
                 else if (ensureLengthSafety)

Runtime/Core/NetworkBehaviourUpdater.cs

@@ -19,10 +19,15 @@ namespace Unity.Netcode
 
         internal void AddForUpdate(NetworkObject networkObject)
         {
+            // Since this is a HashSet, we don't need to worry about duplicate entries
             m_PendingDirtyNetworkObjects.Add(networkObject);
         }
 
-        internal void NetworkBehaviourUpdate()
+        /// <summary>
+        /// Sends NetworkVariable deltas
+        /// </summary>
+        /// <param name="forceSend">internal only, when changing ownership we want to send this before the change in ownership message</param>
+        internal void NetworkBehaviourUpdate(bool forceSend = false)
         {
 #if DEVELOPMENT_BUILD || UNITY_EDITOR
             m_NetworkBehaviourUpdate.Begin();
@@ -53,7 +58,7 @@ namespace Unity.Netcode
                                 // Sync just the variables for just the objects this client sees
                                 for (int k = 0; k < dirtyObj.ChildNetworkBehaviours.Count; k++)
                                 {
-                                    dirtyObj.ChildNetworkBehaviours[k].NetworkVariableUpdate(client.ClientId);
+                                    dirtyObj.ChildNetworkBehaviours[k].NetworkVariableUpdate(client.ClientId, forceSend);
                                 }
                             }
                         }
@@ -72,7 +77,7 @@ namespace Unity.Netcode
                             }
                             for (int k = 0; k < sobj.ChildNetworkBehaviours.Count; k++)
                             {
-                                sobj.ChildNetworkBehaviours[k].NetworkVariableUpdate(NetworkManager.ServerClientId);
+                                sobj.ChildNetworkBehaviours[k].NetworkVariableUpdate(NetworkManager.ServerClientId, forceSend);
                             }
                         }
                     }
@@ -85,19 +90,24 @@ namespace Unity.Netcode
                         var behaviour = dirtyObj.ChildNetworkBehaviours[k];
                         for (int i = 0; i < behaviour.NetworkVariableFields.Count; i++)
                         {
+                            // Set to true for NetworkVariable to ignore duplication of the
+                            // "internal original value" for collections support.
+                            behaviour.NetworkVariableFields[i].NetworkUpdaterCheck = true;
                             if (behaviour.NetworkVariableFields[i].IsDirty() &&
                                 !behaviour.NetworkVariableIndexesToResetSet.Contains(i))
                             {
                                 behaviour.NetworkVariableIndexesToResetSet.Add(i);
                                 behaviour.NetworkVariableIndexesToReset.Add(i);
                             }
+                            // Reset back to false when done
+                            behaviour.NetworkVariableFields[i].NetworkUpdaterCheck = false;
                         }
                     }
                 }
                 // Now, reset all the no-longer-dirty variables
                 foreach (var dirtyobj in m_DirtyNetworkObjects)
                 {
-                    dirtyobj.PostNetworkVariableWrite();
+                    dirtyobj.PostNetworkVariableWrite(forceSend);
                     // Once done processing, we set the previous owner id to the current owner id
                     dirtyobj.PreviousOwnerId = dirtyobj.OwnerClientId;
                 }

Runtime/Core/NetworkManager.cs

@@ -5,6 +5,7 @@ using System.Linq;
 using UnityEngine;
 #if UNITY_EDITOR
 using UnityEditor;
+using PackageInfo = UnityEditor.PackageManager.PackageInfo;
 #endif
 using UnityEngine.SceneManagement;
 using Debug = UnityEngine.Debug;
@@ -17,6 +18,17 @@ namespace Unity.Netcode
     [AddComponentMenu("Netcode/Network Manager", -100)]
     public class NetworkManager : MonoBehaviour, INetworkUpdateSystem
     {
+        /// <summary>
+        /// Subscribe to this static event to get notifications when a <see cref="NetworkManager"/> instance has been instantiated.
+        /// </summary>
+        public static event Action<NetworkManager> OnInstantiated;
+
+        /// <summary>
+        /// Subscribe to this static event to get notifications when a <see cref="NetworkManager"/> instance is being destroyed.
+        /// </summary>
+        public static event Action<NetworkManager> OnDestroying;
+
+
 #if UNITY_EDITOR
         // Inspector view expand/collapse settings for this derived child class
         [HideInInspector]
@@ -874,6 +886,7 @@ namespace Unity.Netcode
 
         internal Override<ushort> PortOverride;
 
+
 #if UNITY_EDITOR
         internal static INetworkManagerHelper NetworkManagerHelper;
 
@@ -900,6 +913,11 @@ namespace Unity.Netcode
 
         }
 
+        private PackageInfo GetPackageInfo(string packageName)
+        {
+            return AssetDatabase.FindAssets("package").Select(AssetDatabase.GUIDToAssetPath).Where(x => AssetDatabase.LoadAssetAtPath<TextAsset>(x) != null).Select(PackageInfo.FindForAssetPath).Where(x => x != null).First(x => x.name == packageName);
+        }
+
         internal void OnValidate()
         {
             if (NetworkConfig == null)
@@ -1030,6 +1048,8 @@ namespace Unity.Netcode
 #if UNITY_EDITOR
             EditorApplication.playModeStateChanged += ModeChanged;
 #endif
+            // Notify we have instantiated a new instance of NetworkManager.
+            OnInstantiated?.Invoke(this);
         }
 
         private void OnEnable()
@@ -1141,9 +1161,6 @@ namespace Unity.Netcode
 
             UpdateTopology();
 
-            //DANGOEXP TODO: Remove this before finalizing the experimental release
-            NetworkConfig.AutoSpawnPlayerPrefabClientSide = DistributedAuthorityMode;
-
             // Make sure the ServerShutdownState is reset when initializing
             if (server)
             {
@@ -1632,6 +1649,9 @@ namespace Unity.Netcode
 
             UnityEngine.SceneManagement.SceneManager.sceneUnloaded -= OnSceneUnloaded;
 
+            // Notify we are destroying NetworkManager
+            OnDestroying?.Invoke(this);
+
             if (Singleton == this)
             {
                 Singleton = null;

Runtime/Core/NetworkObject.cs

@@ -113,11 +113,6 @@ namespace Unity.Netcode
             }
 
             // Handle updating the currently active scene
-            var networkObjects = FindObjectsByType<NetworkObject>(FindObjectsInactive.Include, FindObjectsSortMode.None);
-            foreach (var networkObject in networkObjects)
-            {
-                networkObject.OnValidate();
-            }
             NetworkObjectRefreshTool.ProcessActiveScene();
 
             // Refresh all build settings scenes
@@ -130,14 +125,14 @@ namespace Unity.Netcode
                     continue;
                 }
                 // Add the scene to be processed
-                NetworkObjectRefreshTool.ProcessScene(editorScene.path, false);
+                NetworkObjectRefreshTool.ProcessScene(editorScene.path, true);
             }
 
             // Process all added scenes
             NetworkObjectRefreshTool.ProcessScenes();
         }
 
-        private void OnValidate()
+        internal void OnValidate()
         {
             // do NOT regenerate GlobalObjectIdHash for NetworkPrefabs while Editor is in PlayMode
             if (EditorApplication.isPlaying && !string.IsNullOrEmpty(gameObject.scene.name))
@@ -229,6 +224,7 @@ namespace Unity.Netcode
                 if (sourceAsset != null && sourceAsset.GlobalObjectIdHash != 0 && InScenePlacedSourceGlobalObjectIdHash != sourceAsset.GlobalObjectIdHash)
                 {
                     InScenePlacedSourceGlobalObjectIdHash = sourceAsset.GlobalObjectIdHash;
+                    EditorUtility.SetDirty(this);
                 }
                 IsSceneObject = true;
             }
@@ -340,7 +336,7 @@ namespace Unity.Netcode
 
             if (!HasAuthority)
             {
-                NetworkLog.LogError($"Only the authoirty can invoke {nameof(DeferDespawn)} and local Client-{NetworkManager.LocalClientId} is not the authority of {name}!");
+                NetworkLog.LogError($"Only the authority can invoke {nameof(DeferDespawn)} and local Client-{NetworkManager.LocalClientId} is not the authority of {name}!");
                 return;
             }
 
@@ -1613,7 +1609,12 @@ namespace Unity.Netcode
             }
             else if (NetworkManager.DistributedAuthorityMode && !NetworkManager.DAHost)
             {
-                NetworkManager.SpawnManager.SendSpawnCallForObject(NetworkManager.ServerClientId, this);
+                // If spawning with observers or if not spawning with observers but the observer count is greater than 1 (i.e. owner/authority creating),
+                // then we want to send a spawn notification.
+                if (SpawnWithObservers || !SpawnWithObservers && Observers.Count > 1)
+                {
+                    NetworkManager.SpawnManager.SendSpawnCallForObject(NetworkManager.ServerClientId, this);
+                }
             }
             else
             {
@@ -2444,6 +2445,14 @@ namespace Unity.Netcode
             }
         }
 
+        internal void MarkOwnerReadVariablesDirty()
+        {
+            for (int i = 0; i < ChildNetworkBehaviours.Count; i++)
+            {
+                ChildNetworkBehaviours[i].MarkOwnerReadVariablesDirty();
+            }
+        }
+
         // NGO currently guarantees that the client will receive spawn data for all objects in one network tick.
         //  Children may arrive before their parents; when they do they are stored in OrphanedChildren and then
         //  resolved when their parents arrived.  Because we don't send a partial list of spawns (yet), something
@@ -2770,11 +2779,11 @@ namespace Unity.Netcode
             }
         }
 
-        internal void PostNetworkVariableWrite()
+        internal void PostNetworkVariableWrite(bool forced = false)
         {
             for (int k = 0; k < ChildNetworkBehaviours.Count; k++)
             {
-                ChildNetworkBehaviours[k].PostNetworkVariableWrite();
+                ChildNetworkBehaviours[k].PostNetworkVariableWrite(forced);
             }
         }
 
@@ -3053,10 +3062,15 @@ namespace Unity.Netcode
                         }
                     }
 
-                    // Add all known players to the observers list if they don't already exist
-                    foreach (var player in networkManager.SpawnManager.PlayerObjects)
+                    // Only add all other players as observers if we are spawning with observers,
+                    // otherwise user controls via NetworkShow.
+                    if (networkObject.SpawnWithObservers)
                     {
-                        networkObject.Observers.Add(player.OwnerClientId);
+                        // Add all known players to the observers list if they don't already exist
+                        foreach (var player in networkManager.SpawnManager.PlayerObjects)
+                        {
+                            networkObject.Observers.Add(player.OwnerClientId);
+                        }
                     }
                 }
             }

Runtime/Core/NetworkObjectRefreshTool.cs

@@ -2,6 +2,8 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Text;
+using UnityEditor;
 using UnityEditor.SceneManagement;
 using UnityEngine;
 using UnityEngine.SceneManagement;
@@ -21,6 +23,28 @@ namespace Unity.Netcode
 
         internal static Action AllScenesProcessed;
 
+        internal static NetworkObject PrefabNetworkObject;
+
+        internal static void LogInfo(string msg, bool append = false)
+        {
+            if (!append)
+            {
+                s_Log.AppendLine(msg);
+            }
+            else
+            {
+                s_Log.Append(msg);
+            }
+        }
+
+        internal static void FlushLog()
+        {
+            Debug.Log(s_Log.ToString());
+            s_Log.Clear();
+        }
+
+        private static StringBuilder s_Log = new StringBuilder();
+
         internal static void ProcessScene(string scenePath, bool processScenes = true)
         {
             if (!s_ScenesToUpdate.Contains(scenePath))
@@ -29,7 +53,10 @@ namespace Unity.Netcode
                 {
                     EditorSceneManager.sceneOpened += EditorSceneManager_sceneOpened;
                     EditorSceneManager.sceneSaved += EditorSceneManager_sceneSaved;
+                    s_Log.Clear();
+                    LogInfo("NetworkObject Refresh Scenes to Process:");
                 }
+                LogInfo($"[{scenePath}]", true);
                 s_ScenesToUpdate.Add(scenePath);
             }
             s_ProcessScenes = processScenes;
@@ -37,6 +64,7 @@ namespace Unity.Netcode
 
         internal static void ProcessActiveScene()
         {
+            FlushLog();
             var activeScene = SceneManager.GetActiveScene();
             if (s_ScenesToUpdate.Contains(activeScene.path) && s_ProcessScenes)
             {
@@ -54,10 +82,12 @@ namespace Unity.Netcode
             }
             else
             {
+                s_ProcessScenes = false;
                 s_CloseScenes = false;
                 EditorSceneManager.sceneSaved -= EditorSceneManager_sceneSaved;
                 EditorSceneManager.sceneOpened -= EditorSceneManager_sceneOpened;
                 AllScenesProcessed?.Invoke();
+                FlushLog();
             }
         }
 
@@ -68,9 +98,8 @@ namespace Unity.Netcode
                 // Provide a log of all scenes that were modified to the user
                 if (refreshed)
                 {
-                    Debug.Log($"Refreshed and saved updates to scene: {scene.name}");
+                    LogInfo($"Refreshed and saved updates to scene: {scene.name}");
                 }
-                s_ProcessScenes = false;
                 s_ScenesToUpdate.Remove(scene.path);
 
                 if (scene != SceneManager.GetActiveScene())
@@ -88,24 +117,41 @@ namespace Unity.Netcode
 
         private static void SceneOpened(Scene scene)
         {
+            LogInfo($"Processing scene {scene.name}:");
             if (s_ScenesToUpdate.Contains(scene.path))
             {
                 if (s_ProcessScenes)
                 {
-                    if (!EditorSceneManager.MarkSceneDirty(scene))
+                    var prefabInstances = PrefabUtility.FindAllInstancesOfPrefab(PrefabNetworkObject.gameObject);
+
+                    if (prefabInstances.Length > 0)
                     {
-                        Debug.Log($"Scene {scene.name} did not get marked as dirty!");
-                        FinishedProcessingScene(scene);
-                    }
-                    else
-                    {
-                        EditorSceneManager.SaveScene(scene);
+                        var instancesSceneLoadedSpecific = prefabInstances.Where((c) => c.scene == scene).ToList();
+
+                        if (instancesSceneLoadedSpecific.Count > 0)
+                        {
+                            foreach (var prefabInstance in instancesSceneLoadedSpecific)
+                            {
+                                prefabInstance.GetComponent<NetworkObject>().OnValidate();
+                            }
+
+                            if (!EditorSceneManager.MarkSceneDirty(scene))
+                            {
+                                LogInfo($"Scene {scene.name} did not get marked as dirty!");
+                                FinishedProcessingScene(scene);
+                            }
+                            else
+                            {
+                                LogInfo($"Changes detected and applied!");
+                                EditorSceneManager.SaveScene(scene);
+                            }
+                            return;
+                        }
                     }
                 }
-                else
-                {
-                    FinishedProcessingScene(scene);
-                }
+
+                LogInfo($"No changes required.");
+                FinishedProcessingScene(scene);
             }
         }
 

Runtime/Messaging/Messages/ChangeOwnershipMessage.cs

@@ -9,7 +9,6 @@ namespace Unity.Netcode
 
         public ulong NetworkObjectId;
         public ulong OwnerClientId;
-        // DANGOEXP TODO: Remove these notes or change their format
         // SERVICE NOTES:
         // When forwarding the message to clients on the CMB Service side,
         // you can set the ClientIdCount to 0 and skip writing the ClientIds.
@@ -258,15 +257,18 @@ namespace Unity.Netcode
                             continue;
                         }
 
-                        // If ownership is changing and this is not an ownership request approval then ignore the OnwerClientId
-                        // If it is just updating flags then ignore sending to the owner
-                        // If it is a request or approving request, then ignore the RequestClientId
-                        if ((OwnershipIsChanging && !RequestApproved && OwnerClientId == clientId) || (OwnershipFlagsUpdate && clientId == OwnerClientId)
-                            || ((RequestOwnership || RequestApproved) && clientId == RequestClientId))
+                        // If ownership is changing and this is not an ownership request approval then ignore the SenderId
+                        if (OwnershipIsChanging && !RequestApproved && context.SenderId == clientId)
                         {
                             continue;
                         }
 
+                        // If it is just updating flags then ignore sending to the owner
+                        // If it is a request or approving request, then ignore the RequestClientId
+                        if ((OwnershipFlagsUpdate && clientId == OwnerClientId) || ((RequestOwnership || RequestApproved) && clientId == RequestClientId))
+                        {
+                            continue;
+                        }
                         networkManager.ConnectionManager.SendMessage(ref message, NetworkDelivery.Reliable, clientId);
                     }
                 }
@@ -327,10 +329,12 @@ namespace Unity.Netcode
             var networkManager = (NetworkManager)context.SystemOwner;
             var networkObject = networkManager.SpawnManager.SpawnedObjects[NetworkObjectId];
 
-            // DANGO-TODO: This probably shouldn't be allowed to happen.
+            // Sanity check that we are not sending duplicated change ownership messages
             if (networkObject.OwnerClientId == OwnerClientId)
             {
-                UnityEngine.Debug.LogWarning($"Unnecessary ownership changed message for {NetworkObjectId}");
+                UnityEngine.Debug.LogError($"Unnecessary ownership changed message for {NetworkObjectId}.");
+                // Ignore the message
+                return;
             }
 
             var originalOwner = networkObject.OwnerClientId;
@@ -347,12 +351,6 @@ namespace Unity.Netcode
                 networkObject.InvokeBehaviourOnLostOwnership();
             }
 
-            // We are new owner or (client-server) or running in distributed authority mode
-            if (OwnerClientId == networkManager.LocalClientId || networkManager.DistributedAuthorityMode)
-            {
-                networkObject.InvokeBehaviourOnGainedOwnership();
-            }
-
             // If in distributed authority mode 
             if (networkManager.DistributedAuthorityMode)
             {
@@ -374,6 +372,22 @@ namespace Unity.Netcode
                 }
             }
 
+            // We are new owner or (client-server) or running in distributed authority mode
+            if (OwnerClientId == networkManager.LocalClientId || networkManager.DistributedAuthorityMode)
+            {
+                networkObject.InvokeBehaviourOnGainedOwnership();
+            }
+
+
+            if (originalOwner == networkManager.LocalClientId && !networkManager.DistributedAuthorityMode)
+            {
+                // Mark any owner read variables as dirty
+                networkObject.MarkOwnerReadVariablesDirty();
+                // Immediately queue any pending deltas and order the message before the
+                // change in ownership message.
+                networkManager.BehaviourUpdater.NetworkBehaviourUpdate(true);
+            }
+
             // Always invoke ownership change notifications
             networkObject.InvokeOwnershipChanged(originalOwner, OwnerClientId);
 

Runtime/Messaging/Messages/ConnectionApprovedMessage.cs

@@ -3,14 +3,39 @@ using Unity.Collections;
 
 namespace Unity.Netcode
 {
+    internal struct ServiceConfig : INetworkSerializable
+    {
+        public uint Version;
+        public bool IsRestoredSession;
+        public ulong CurrentSessionOwner;
+
+        public void NetworkSerialize<T>(BufferSerializer<T> serializer) where T : IReaderWriter
+        {
+            if (serializer.IsWriter)
+            {
+                BytePacker.WriteValueBitPacked(serializer.GetFastBufferWriter(), Version);
+                serializer.SerializeValue(ref IsRestoredSession);
+                BytePacker.WriteValueBitPacked(serializer.GetFastBufferWriter(), CurrentSessionOwner);
+            }
+            else
+            {
+                ByteUnpacker.ReadValueBitPacked(serializer.GetFastBufferReader(), out Version);
+                serializer.SerializeValue(ref IsRestoredSession);
+                ByteUnpacker.ReadValueBitPacked(serializer.GetFastBufferReader(), out CurrentSessionOwner);
+            }
+        }
+    }
+
     internal struct ConnectionApprovedMessage : INetworkMessage
     {
+        private const int k_AddCMBServiceConfig = 2;
         private const int k_VersionAddClientIds = 1;
-        public int Version => k_VersionAddClientIds;
+        public int Version => k_AddCMBServiceConfig;
 
         public ulong OwnerClientId;
         public int NetworkTick;
         // The cloud state service should set this if we are restoring a session
+        public ServiceConfig ServiceConfig;
         public bool IsRestoredSession;
         public ulong CurrentSessionOwner;
         // Not serialized
@@ -25,6 +50,32 @@ namespace Unity.Netcode
 
         public NativeArray<ulong> ConnectedClientIds;
 
+        private int m_ReceiveMessageVersion;
+
+        private ulong GetSessionOwner()
+        {
+            if (m_ReceiveMessageVersion >= k_AddCMBServiceConfig)
+            {
+                return ServiceConfig.CurrentSessionOwner;
+            }
+            else
+            {
+                return CurrentSessionOwner;
+            }
+        }
+
+        private bool GetIsSessionRestor()
+        {
+            if (m_ReceiveMessageVersion >= k_AddCMBServiceConfig)
+            {
+                return ServiceConfig.IsRestoredSession;
+            }
+            else
+            {
+                return IsRestoredSession;
+            }
+        }
+
         public void Serialize(FastBufferWriter writer, int targetVersion)
         {
             // ============================================================
@@ -45,8 +96,17 @@ namespace Unity.Netcode
             BytePacker.WriteValueBitPacked(writer, NetworkTick);
             if (IsDistributedAuthority)
             {
-                writer.WriteValueSafe(IsRestoredSession);
-                BytePacker.WriteValueBitPacked(writer, CurrentSessionOwner);
+                if (targetVersion >= k_AddCMBServiceConfig)
+                {
+                    ServiceConfig.IsRestoredSession = false;
+                    ServiceConfig.CurrentSessionOwner = CurrentSessionOwner;
+                    writer.WriteNetworkSerializable(ServiceConfig);
+                }
+                else
+                {
+                    writer.WriteValueSafe(IsRestoredSession);
+                    BytePacker.WriteValueBitPacked(writer, CurrentSessionOwner);
+                }
             }
 
             if (targetVersion >= k_VersionAddClientIds)
@@ -122,13 +182,20 @@ namespace Unity.Netcode
             // ============================================================
             // END FORBIDDEN SEGMENT
             // ============================================================
-
+            m_ReceiveMessageVersion = receivedMessageVersion;
             ByteUnpacker.ReadValueBitPacked(reader, out OwnerClientId);
             ByteUnpacker.ReadValueBitPacked(reader, out NetworkTick);
             if (networkManager.DistributedAuthorityMode)
             {
-                reader.ReadValueSafe(out IsRestoredSession);
-                ByteUnpacker.ReadValueBitPacked(reader, out CurrentSessionOwner);
+                if (receivedMessageVersion >= k_AddCMBServiceConfig)
+                {
+                    reader.ReadNetworkSerializable(out ServiceConfig);
+                }
+                else
+                {
+                    reader.ReadValueSafe(out IsRestoredSession);
+                    ByteUnpacker.ReadValueBitPacked(reader, out CurrentSessionOwner);
+                }
             }
 
             if (receivedMessageVersion >= k_VersionAddClientIds)
@@ -157,7 +224,7 @@ namespace Unity.Netcode
 
             if (networkManager.DistributedAuthorityMode)
             {
-                networkManager.SetSessionOwner(CurrentSessionOwner);
+                networkManager.SetSessionOwner(GetSessionOwner());
                 if (networkManager.LocalClient.IsSessionOwner && networkManager.NetworkConfig.EnableSceneManagement)
                 {
                     networkManager.SceneManager.InitializeScenesLoaded();
@@ -233,9 +300,9 @@ namespace Unity.Netcode
                     // Mark the client being connected
                     networkManager.IsConnectedClient = true;
 
-                    networkManager.SceneManager.IsRestoringSession = IsRestoredSession;
+                    networkManager.SceneManager.IsRestoringSession = GetIsSessionRestor();
 
-                    if (!IsRestoredSession)
+                    if (!networkManager.SceneManager.IsRestoringSession)
                     {
                         // Synchronize the service with the initial session owner's loaded scenes and spawned objects
                         networkManager.SceneManager.SynchronizeNetworkObjects(NetworkManager.ServerClientId);

Runtime/Messaging/Messages/ConnectionRequestMessage.cs

@@ -2,16 +2,54 @@ using Unity.Collections;
 
 namespace Unity.Netcode
 {
-    internal struct ConnectionRequestMessage : INetworkMessage
+    /// <summary>
+    /// Only used when connecting to the distributed authority service
+    /// </summary>
+    internal struct ClientConfig : INetworkSerializable
     {
-        public int Version => 0;
-
-        public ulong ConfigHash;
-
-        public bool CMBServiceConnection;
+        /// <summary>
+        /// We start at version 1, where anything less than version 1 on the service side
+        /// is not bypass feature compatible.
+        /// </summary>
+        private const int k_BypassFeatureCompatible = 1;
+        public int Version => k_BypassFeatureCompatible;
         public uint TickRate;
         public bool EnableSceneManagement;
 
+        // Only gets deserialized but should never be used unless testing
+        public int RemoteClientVersion;
+
+        public void NetworkSerialize<T>(BufferSerializer<T> serializer) where T : IReaderWriter
+        {
+            if (serializer.IsWriter)
+            {
+                var writer = serializer.GetFastBufferWriter();
+                BytePacker.WriteValueBitPacked(writer, Version);
+                BytePacker.WriteValueBitPacked(writer, TickRate);
+                writer.WriteValueSafe(EnableSceneManagement);
+            }
+            else
+            {
+                var reader = serializer.GetFastBufferReader();
+                ByteUnpacker.ReadValueBitPacked(reader, out RemoteClientVersion);
+                ByteUnpacker.ReadValueBitPacked(reader, out TickRate);
+                reader.ReadValueSafe(out EnableSceneManagement);
+            }
+        }
+    }
+
+    internal struct ConnectionRequestMessage : INetworkMessage
+    {
+        // This version update is unidirectional (client to service) and version
+        // handling occurs on the service side. This serialized data is never sent
+        // to a host or server.
+        private const int k_SendClientConfigToService = 1;
+        public int Version => k_SendClientConfigToService;
+
+        public ulong ConfigHash;
+        public bool CMBServiceConnection;
+        public ClientConfig ClientConfig;
+
         public byte[] ConnectionData;
 
         public bool ShouldSendConnectionData;
@@ -36,8 +74,7 @@ namespace Unity.Netcode
 
             if (CMBServiceConnection)
             {
-                writer.WriteValueSafe(TickRate);
-                writer.WriteValueSafe(EnableSceneManagement);
+                writer.WriteNetworkSerializable(ClientConfig);
             }
 
             if (ShouldSendConnectionData)

Runtime/Messaging/Messages/NetworkVariableDeltaMessage.cs

@@ -1,5 +1,6 @@
 using System;
 using System.Collections.Generic;
+using System.Runtime.CompilerServices;
 using Unity.Collections;
 
 namespace Unity.Netcode
@@ -10,9 +11,22 @@ namespace Unity.Netcode
     /// serialization. This is due to the generally amorphous nature of network variable
     /// deltas, since they're all driven by custom virtual method overloads.
     /// </summary>
+    /// <remarks>
+    /// Version 1:
+    /// This version -does not- use the "KeepDirty" approach. Instead, the server will forward any state updates
+    /// to the connected clients that are not the sender or the server itself. Each NetworkVariable state update
+    /// included, on a per client basis, is first validated that the client can read the NetworkVariable before
+    /// being added to the m_ForwardUpdates table.
+    /// Version 0:
+    /// The original version uses the "KeepDirty" approach in a client-server network topology where the server
+    /// proxies state updates by "keeping the NetworkVariable(s) dirty" so it will send state updates
+    /// at the end of the frame (but could delay until the next tick).
+    /// </remarks>
     internal struct NetworkVariableDeltaMessage : INetworkMessage
     {
-        public int Version => 0;
+        private const int k_ServerDeltaForwardingAndNetworkDelivery = 1;
+        public int Version => k_ServerDeltaForwardingAndNetworkDelivery;
+
 
         public ulong NetworkObjectId;
         public ushort NetworkBehaviourIndex;
@@ -21,10 +35,62 @@ namespace Unity.Netcode
         public ulong TargetClientId;
         public NetworkBehaviour NetworkBehaviour;
 
+        public NetworkDelivery NetworkDelivery;
+
         private FastBufferReader m_ReceivedNetworkVariableData;
 
+        private bool m_ForwardingMessage;
+
+        private int m_ReceivedMessageVersion;
+
         private const string k_Name = "NetworkVariableDeltaMessage";
 
+        private Dictionary<ulong, List<int>> m_ForwardUpdates;
+
+        private List<int> m_UpdatedNetworkVariables;
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        private void WriteNetworkVariable(ref FastBufferWriter writer, ref NetworkVariableBase networkVariable, bool distributedAuthorityMode, bool ensureNetworkVariableLengthSafety, int nonfragmentedSize, int fragmentedSize)
+        {
+            if (ensureNetworkVariableLengthSafety)
+            {
+                var tempWriter = new FastBufferWriter(nonfragmentedSize, Allocator.Temp, fragmentedSize);
+                networkVariable.WriteDelta(tempWriter);
+                BytePacker.WriteValueBitPacked(writer, tempWriter.Length);
+
+                if (!writer.TryBeginWrite(tempWriter.Length))
+                {
+                    throw new OverflowException($"Not enough space in the buffer to write {nameof(NetworkVariableDeltaMessage)}");
+                }
+
+                tempWriter.CopyTo(writer);
+            }
+            else
+            {
+                // TODO: Determine if we need to remove this with the 6.1 service updates
+                if (distributedAuthorityMode)
+                {
+                    var size_marker = writer.Position;
+                    writer.WriteValueSafe<ushort>(0);
+                    var start_marker = writer.Position;
+                    networkVariable.WriteDelta(writer);
+                    var end_marker = writer.Position;
+                    writer.Seek(size_marker);
+                    var size = end_marker - start_marker;
+                    if (size == 0)
+                    {
+                        UnityEngine.Debug.LogError($"Invalid write size of zero!");
+                    }
+                    writer.WriteValueSafe((ushort)size);
+                    writer.Seek(end_marker);
+                }
+                else
+                {
+                    networkVariable.WriteDelta(writer);
+                }
+            }
+        }
+
         public void Serialize(FastBufferWriter writer, int targetVersion)
         {
             if (!writer.TryBeginWrite(FastBufferWriter.GetWriteSize(NetworkObjectId) + FastBufferWriter.GetWriteSize(NetworkBehaviourIndex)))
@@ -34,10 +100,67 @@ namespace Unity.Netcode
 
             var obj = NetworkBehaviour.NetworkObject;
             var networkManager = obj.NetworkManagerOwner;
+            var typeName = NetworkBehaviour.__getTypeName();
+            var nonFragmentedMessageMaxSize = networkManager.MessageManager.NonFragmentedMessageMaxSize;
+            var fragmentedMessageMaxSize = networkManager.MessageManager.FragmentedMessageMaxSize;
+            var ensureNetworkVariableLengthSafety = networkManager.NetworkConfig.EnsureNetworkVariableLengthSafety;
+            var distributedAuthorityMode = networkManager.DistributedAuthorityMode;
 
             BytePacker.WriteValueBitPacked(writer, NetworkObjectId);
             BytePacker.WriteValueBitPacked(writer, NetworkBehaviourIndex);
-            if (networkManager.DistributedAuthorityMode)
+
+            // If using k_IncludeNetworkDelivery version, then we want to write the network delivery used and if we
+            // are forwarding state updates then serialize any NetworkVariable states specific to this client.
+            if (targetVersion >= k_ServerDeltaForwardingAndNetworkDelivery)
+            {
+                writer.WriteValueSafe(NetworkDelivery);
+                // If we are forwarding the message, then proceed to forward state updates specific to the targeted client
+                if (m_ForwardingMessage)
+                {
+                    // DANGO TODO: Remove distributedAuthorityMode portion when we remove the service specific NetworkVariable stuff
+                    if (distributedAuthorityMode)
+                    {
+                        writer.WriteValueSafe((ushort)NetworkBehaviour.NetworkVariableFields.Count);
+                    }
+
+                    for (int i = 0; i < NetworkBehaviour.NetworkVariableFields.Count; i++)
+                    {
+                        var startingSize = writer.Length;
+                        var networkVariable = NetworkBehaviour.NetworkVariableFields[i];
+                        var shouldWrite = m_ForwardUpdates[TargetClientId].Contains(i);
+
+                        // This var does not belong to the currently iterating delivery group.
+                        if (distributedAuthorityMode)
+                        {
+                            if (!shouldWrite)
+                            {
+                                writer.WriteValueSafe<ushort>(0);
+                            }
+                        }
+                        else if (ensureNetworkVariableLengthSafety)
+                        {
+                            if (!shouldWrite)
+                            {
+                                BytePacker.WriteValueBitPacked(writer, (ushort)0);
+                            }
+                        }
+                        else
+                        {
+                            writer.WriteValueSafe(shouldWrite);
+                        }
+
+                        if (shouldWrite)
+                        {
+                            WriteNetworkVariable(ref writer, ref networkVariable, distributedAuthorityMode, ensureNetworkVariableLengthSafety, nonFragmentedMessageMaxSize, fragmentedMessageMaxSize);
+                            networkManager.NetworkMetrics.TrackNetworkVariableDeltaSent(TargetClientId, obj, networkVariable.Name, typeName, writer.Length - startingSize);
+                        }
+                    }
+                    return;
+                }
+            }
+
+            // DANGO TODO: Remove this when we remove the service specific NetworkVariable stuff
+            if (distributedAuthorityMode)
             {
                 writer.WriteValueSafe((ushort)NetworkBehaviour.NetworkVariableFields.Count);
             }
@@ -46,12 +169,12 @@ namespace Unity.Netcode
             {
                 if (!DeliveryMappedNetworkVariableIndex.Contains(i))
                 {
-                    // This var does not belong to the currently iterating delivery group.
-                    if (networkManager.DistributedAuthorityMode)
+                    // DANGO TODO: Remove distributedAuthorityMode portion when we remove the service specific NetworkVariable stuff
+                    if (distributedAuthorityMode)
                     {
                         writer.WriteValueSafe<ushort>(0);
                     }
-                    else if (networkManager.NetworkConfig.EnsureNetworkVariableLengthSafety)
+                    else if (ensureNetworkVariableLengthSafety)
                     {
                         BytePacker.WriteValueBitPacked(writer, (ushort)0);
                     }
@@ -88,14 +211,15 @@ namespace Unity.Netcode
                     shouldWrite = false;
                 }
 
-                if (networkManager.DistributedAuthorityMode)
+                // DANGO TODO: Remove distributedAuthorityMode portion when we remove the service specific NetworkVariable stuff
+                if (distributedAuthorityMode)
                 {
                     if (!shouldWrite)
                     {
                         writer.WriteValueSafe<ushort>(0);
                     }
                 }
-                else if (networkManager.NetworkConfig.EnsureNetworkVariableLengthSafety)
+                else if (ensureNetworkVariableLengthSafety)
                 {
                     if (!shouldWrite)
                     {
@@ -109,53 +233,22 @@ namespace Unity.Netcode
 
                 if (shouldWrite)
                 {
-                    if (networkManager.NetworkConfig.EnsureNetworkVariableLengthSafety)
-                    {
-                        var tempWriter = new FastBufferWriter(networkManager.MessageManager.NonFragmentedMessageMaxSize, Allocator.Temp, networkManager.MessageManager.FragmentedMessageMaxSize);
-                        NetworkBehaviour.NetworkVariableFields[i].WriteDelta(tempWriter);
-                        BytePacker.WriteValueBitPacked(writer, tempWriter.Length);
-
-                        if (!writer.TryBeginWrite(tempWriter.Length))
-                        {
-                            throw new OverflowException($"Not enough space in the buffer to write {nameof(NetworkVariableDeltaMessage)}");
-                        }
-
-                        tempWriter.CopyTo(writer);
-                    }
-                    else
-                    {
-                        if (networkManager.DistributedAuthorityMode)
-                        {
-                            var size_marker = writer.Position;
-                            writer.WriteValueSafe<ushort>(0);
-                            var start_marker = writer.Position;
-                            networkVariable.WriteDelta(writer);
-                            var end_marker = writer.Position;
-                            writer.Seek(size_marker);
-                            var size = end_marker - start_marker;
-                            writer.WriteValueSafe((ushort)size);
-                            writer.Seek(end_marker);
-                        }
-                        else
-                        {
-                            networkVariable.WriteDelta(writer);
-                        }
-                    }
-                    networkManager.NetworkMetrics.TrackNetworkVariableDeltaSent(
-                        TargetClientId,
-                        obj,
-                        networkVariable.Name,
-                        NetworkBehaviour.__getTypeName(),
-                        writer.Length - startingSize);
+                    WriteNetworkVariable(ref writer, ref networkVariable, distributedAuthorityMode, ensureNetworkVariableLengthSafety, nonFragmentedMessageMaxSize, fragmentedMessageMaxSize);
+                    networkManager.NetworkMetrics.TrackNetworkVariableDeltaSent(TargetClientId, obj, networkVariable.Name, typeName, writer.Length - startingSize);
                 }
             }
         }
 
         public bool Deserialize(FastBufferReader reader, ref NetworkContext context, int receivedMessageVersion)
         {
+            m_ReceivedMessageVersion = receivedMessageVersion;
             ByteUnpacker.ReadValueBitPacked(reader, out NetworkObjectId);
             ByteUnpacker.ReadValueBitPacked(reader, out NetworkBehaviourIndex);
-
+            // If we are using the k_IncludeNetworkDelivery message version, then read the NetworkDelivery used
+            if (receivedMessageVersion >= k_ServerDeltaForwardingAndNetworkDelivery)
+            {
+                reader.ReadValueSafe(out NetworkDelivery);
+            }
             m_ReceivedNetworkVariableData = reader;
 
             return true;
@@ -167,7 +260,12 @@ namespace Unity.Netcode
 
             if (networkManager.SpawnManager.SpawnedObjects.TryGetValue(NetworkObjectId, out NetworkObject networkObject))
             {
+                var distributedAuthorityMode = networkManager.DistributedAuthorityMode;
+                var ensureNetworkVariableLengthSafety = networkManager.NetworkConfig.EnsureNetworkVariableLengthSafety;
                 var networkBehaviour = networkObject.GetNetworkBehaviourAtOrderIndex(NetworkBehaviourIndex);
+                var isServerAndDeltaForwarding = m_ReceivedMessageVersion >= k_ServerDeltaForwardingAndNetworkDelivery && networkManager.IsServer;
+                var markNetworkVariableDirty = m_ReceivedMessageVersion >= k_ServerDeltaForwardingAndNetworkDelivery ? false : networkManager.IsServer;
+                m_UpdatedNetworkVariables = new List<int>();
 
                 if (networkBehaviour == null)
                 {
@@ -178,7 +276,8 @@ namespace Unity.Netcode
                 }
                 else
                 {
-                    if (networkManager.DistributedAuthorityMode)
+                    // DANGO TODO: Remove distributedAuthorityMode portion when we remove the service specific NetworkVariable stuff
+                    if (distributedAuthorityMode)
                     {
                         m_ReceivedNetworkVariableData.ReadValueSafe(out ushort variableCount);
                         if (variableCount != networkBehaviour.NetworkVariableFields.Count)
@@ -187,10 +286,30 @@ namespace Unity.Netcode
                         }
                     }
 
+                    // (For client-server) As opposed to worrying about adding additional processing on the server to send NetworkVariable
+                    // updates at the end of the frame, we now track all NetworkVariable state updates, per client, that need to be forwarded
+                    // to the client. This creates a list of all remaining connected clients that could have updates applied.
+                    if (isServerAndDeltaForwarding)
+                    {
+                        m_ForwardUpdates = new Dictionary<ulong, List<int>>();
+                        foreach (var clientId in networkManager.ConnectedClientsIds)
+                        {
+                            if (clientId == context.SenderId || clientId == networkManager.LocalClientId || !networkObject.Observers.Contains(clientId))
+                            {
+                                continue;
+                            }
+                            m_ForwardUpdates.Add(clientId, new List<int>());
+                        }
+                    }
+
+                    // Update NetworkVariable Fields
                     for (int i = 0; i < networkBehaviour.NetworkVariableFields.Count; i++)
                     {
                         int varSize = 0;
-                        if (networkManager.DistributedAuthorityMode)
+                        var networkVariable = networkBehaviour.NetworkVariableFields[i];
+
+                        // DANGO TODO: Remove distributedAuthorityMode portion when we remove the service specific NetworkVariable stuff
+                        if (distributedAuthorityMode)
                         {
                             m_ReceivedNetworkVariableData.ReadValueSafe(out ushort variableSize);
                             varSize = variableSize;
@@ -200,10 +319,9 @@ namespace Unity.Netcode
                                 continue;
                             }
                         }
-                        else if (networkManager.NetworkConfig.EnsureNetworkVariableLengthSafety)
+                        else if (ensureNetworkVariableLengthSafety)
                         {
                             ByteUnpacker.ReadValueBitPacked(m_ReceivedNetworkVariableData, out varSize);
-
                             if (varSize == 0)
                             {
                                 continue;
@@ -218,8 +336,6 @@ namespace Unity.Netcode
                             }
                         }
 
-                        var networkVariable = networkBehaviour.NetworkVariableFields[i];
-
                         if (networkManager.IsServer && !networkVariable.CanClientWrite(context.SenderId))
                         {
                             // we are choosing not to fire an exception here, because otherwise a malicious client could use this to crash the server
@@ -247,13 +363,58 @@ namespace Unity.Netcode
                                 NetworkLog.LogError($"Client wrote to {typeof(NetworkVariable<>).Name} without permission. No more variables can be read. This is critical. => {nameof(NetworkObjectId)}: {NetworkObjectId} - {nameof(NetworkObject.GetNetworkBehaviourOrderIndex)}(): {networkObject.GetNetworkBehaviourOrderIndex(networkBehaviour)} - VariableIndex: {i}");
                                 NetworkLog.LogError($"[{networkVariable.GetType().Name}]");
                             }
-
                             return;
                         }
                         int readStartPos = m_ReceivedNetworkVariableData.Position;
 
-                        // Read Delta so we also notify any subscribers to a change in the NetworkVariable
-                        networkVariable.ReadDelta(m_ReceivedNetworkVariableData, networkManager.IsServer);
+                        // DANGO TODO: Remove distributedAuthorityMode portion when we remove the service specific NetworkVariable stuff
+                        if (distributedAuthorityMode || ensureNetworkVariableLengthSafety)
+                        {
+                            var remainingBufferSize = m_ReceivedNetworkVariableData.Length - m_ReceivedNetworkVariableData.Position;
+                            if (varSize > (remainingBufferSize))
+                            {
+                                UnityEngine.Debug.LogError($"[{networkBehaviour.name}][Delta State Read Error] Expecting to read {varSize} but only {remainingBufferSize} remains!");
+                                return;
+                            }
+                        }
+
+                        // Added a try catch here to assure any failure will only fail on this one message and not disrupt the stack
+                        try
+                        {
+                            // Read the delta
+                            networkVariable.ReadDelta(m_ReceivedNetworkVariableData, markNetworkVariableDirty);
+
+                            // Add the NetworkVariable field index so we can invoke the PostDeltaRead
+                            m_UpdatedNetworkVariables.Add(i);
+                        }
+                        catch (Exception ex)
+                        {
+                            UnityEngine.Debug.LogException(ex);
+                            return;
+                        }
+
+                        // (For client-server) As opposed to worrying about adding additional processing on the server to send NetworkVariable
+                        // updates at the end of the frame, we now track all NetworkVariable state updates, per client, that need to be forwarded
+                        // to the client. This happens once the server is finished processing all state updates for this message.
+                        if (isServerAndDeltaForwarding)
+                        {
+                            foreach (var forwardEntry in m_ForwardUpdates)
+                            {
+                                // Only track things that the client can read
+                                if (networkVariable.CanClientRead(forwardEntry.Key))
+                                {
+                                    // If the object is about to be shown to the client then don't send an update as it will
+                                    // send a full update when shown.
+                                    if (networkManager.SpawnManager.ObjectsToShowToClient.ContainsKey(forwardEntry.Key) &&
+                                        networkManager.SpawnManager.ObjectsToShowToClient[forwardEntry.Key]
+                                        .Contains(networkObject))
+                                    {
+                                        continue;
+                                    }
+                                    forwardEntry.Value.Add(i);
+                                }
+                            }
+                        }
 
                         networkManager.NetworkMetrics.TrackNetworkVariableDeltaReceived(
                             context.SenderId,
@@ -262,7 +423,8 @@ namespace Unity.Netcode
                             networkBehaviour.__getTypeName(),
                             context.MessageSize);
 
-                        if (networkManager.NetworkConfig.EnsureNetworkVariableLengthSafety || networkManager.DistributedAuthorityMode)
+                        // DANGO TODO: Remove distributedAuthorityMode portion when we remove the service specific NetworkVariable stuff
+                        if (distributedAuthorityMode || ensureNetworkVariableLengthSafety)
                         {
                             if (m_ReceivedNetworkVariableData.Position > (readStartPos + varSize))
                             {
@@ -284,6 +446,40 @@ namespace Unity.Netcode
                             }
                         }
                     }
+
+                    // If we are using the version of this message that includes network delivery, then
+                    // forward this update to all connected clients (other than the sender and the server).
+                    if (isServerAndDeltaForwarding)
+                    {
+                        var message = new NetworkVariableDeltaMessage()
+                        {
+                            NetworkBehaviour = networkBehaviour,
+                            NetworkBehaviourIndex = NetworkBehaviourIndex,
+                            NetworkObjectId = NetworkObjectId,
+                            m_ForwardingMessage = true,
+                            m_ForwardUpdates = m_ForwardUpdates,
+                        };
+
+                        foreach (var forwardEntry in m_ForwardUpdates)
+                        {
+                            // Only forward updates to any client that has visibility to the state updates included in this message
+                            if (forwardEntry.Value.Count > 0)
+                            {
+                                message.TargetClientId = forwardEntry.Key;
+                                networkManager.ConnectionManager.SendMessage(ref message, NetworkDelivery, forwardEntry.Key);
+                            }
+                        }
+                    }
+
+                    // This should be always invoked (client & server) to assure the previous values are set
+                    // !! IMPORTANT ORDER OF OPERATIONS !! (Has to happen after forwarding deltas)
+                    // When a server forwards delta updates to connected clients, it needs to preserve the previous value
+                    // until it is done serializing all valid NetworkVariable field deltas (relative to each client). This
+                    // is invoked after it is done forwarding the deltas.
+                    foreach (var fieldIndex in m_UpdatedNetworkVariables)
+                    {
+                        networkBehaviour.NetworkVariableFields[fieldIndex].PostDeltaRead();
+                    }
                 }
             }
             else

Runtime/NetworkVariable/Collections/NetworkList.cs

@@ -177,6 +177,13 @@ namespace Unity.Netcode
         /// <inheritdoc />
         public override void ReadDelta(FastBufferReader reader, bool keepDirtyDelta)
         {
+            /// This is only invoked by <see cref="NetworkVariableDeltaMessage"/> and the only time
+            /// keepDirtyDelta is set is when it is the server processing. To be able to handle previous
+            /// versions, we use IsServer to keep the dirty states received and the keepDirtyDelta to
+            /// actually mark this as dirty and add it to the list of <see cref="NetworkObject"/>s to
+            /// be updated. With the forwarding of deltas being handled by <see cref="NetworkVariableDeltaMessage"/>,
+            /// once all clients have been forwarded the dirty events, we clear them by invoking <see cref="PostDeltaRead"/>.
+            var isServer = m_NetworkManager.IsServer;
             reader.ReadValueSafe(out ushort deltaCount);
             for (int i = 0; i < deltaCount; i++)
             {
@@ -199,7 +206,7 @@ namespace Unity.Netcode
                                 });
                             }
 
-                            if (keepDirtyDelta)
+                            if (isServer)
                             {
                                 m_DirtyEvents.Add(new NetworkListEvent<T>()
                                 {
@@ -207,7 +214,11 @@ namespace Unity.Netcode
                                     Index = m_List.Length - 1,
                                     Value = m_List[m_List.Length - 1]
                                 });
-                                MarkNetworkObjectDirty();
+                                // Preserve the legacy way of handling this
+                                if (keepDirtyDelta)
+                                {
+                                    MarkNetworkObjectDirty();
+                                }
                             }
                         }
                         break;
@@ -237,7 +248,7 @@ namespace Unity.Netcode
                                 });
                             }
 
-                            if (keepDirtyDelta)
+                            if (isServer)
                             {
                                 m_DirtyEvents.Add(new NetworkListEvent<T>()
                                 {
@@ -245,7 +256,11 @@ namespace Unity.Netcode
                                     Index = index,
                                     Value = m_List[index]
                                 });
-                                MarkNetworkObjectDirty();
+                                // Preserve the legacy way of handling this
+                                if (keepDirtyDelta)
+                                {
+                                    MarkNetworkObjectDirty();
+                                }
                             }
                         }
                         break;
@@ -271,7 +286,7 @@ namespace Unity.Netcode
                                 });
                             }
 
-                            if (keepDirtyDelta)
+                            if (isServer)
                             {
                                 m_DirtyEvents.Add(new NetworkListEvent<T>()
                                 {
@@ -279,7 +294,11 @@ namespace Unity.Netcode
                                     Index = index,
                                     Value = value
                                 });
-                                MarkNetworkObjectDirty();
+                                // Preserve the legacy way of handling this
+                                if (keepDirtyDelta)
+                                {
+                                    MarkNetworkObjectDirty();
+                                }
                             }
                         }
                         break;
@@ -299,7 +318,7 @@ namespace Unity.Netcode
                                 });
                             }
 
-                            if (keepDirtyDelta)
+                            if (isServer)
                             {
                                 m_DirtyEvents.Add(new NetworkListEvent<T>()
                                 {
@@ -307,7 +326,11 @@ namespace Unity.Netcode
                                     Index = index,
                                     Value = value
                                 });
-                                MarkNetworkObjectDirty();
+                                // Preserve the legacy way of handling this
+                                if (keepDirtyDelta)
+                                {
+                                    MarkNetworkObjectDirty();
+                                }
                             }
                         }
                         break;
@@ -335,7 +358,7 @@ namespace Unity.Netcode
                                 });
                             }
 
-                            if (keepDirtyDelta)
+                            if (isServer)
                             {
                                 m_DirtyEvents.Add(new NetworkListEvent<T>()
                                 {
@@ -344,7 +367,11 @@ namespace Unity.Netcode
                                     Value = value,
                                     PreviousValue = previousValue
                                 });
-                                MarkNetworkObjectDirty();
+                                // Preserve the legacy way of handling this
+                                if (keepDirtyDelta)
+                                {
+                                    MarkNetworkObjectDirty();
+                                }
                             }
                         }
                         break;
@@ -361,13 +388,18 @@ namespace Unity.Netcode
                                 });
                             }
 
-                            if (keepDirtyDelta)
+                            if (isServer)
                             {
                                 m_DirtyEvents.Add(new NetworkListEvent<T>()
                                 {
                                     Type = eventType
                                 });
-                                MarkNetworkObjectDirty();
+
+                                // Preserve the legacy way of handling this
+                                if (keepDirtyDelta)
+                                {
+                                    MarkNetworkObjectDirty();
+                                }
                             }
                         }
                         break;
@@ -381,6 +413,18 @@ namespace Unity.Netcode
             }
         }
 
+        /// <inheritdoc />
+        /// <remarks>
+        /// For NetworkList, we just need to reset dirty if a server has read deltas
+        /// </remarks>
+        internal override void PostDeltaRead()
+        {
+            if (m_NetworkManager.IsServer)
+            {
+                ResetDirty();
+            }
+        }
+
         /// <inheritdoc />
         public IEnumerator<T> GetEnumerator()
         {

Runtime/NetworkVariable/NetworkVariable.cs

@@ -41,6 +41,7 @@ namespace Unity.Netcode
             base.OnInitialize();
 
             m_HasPreviousValue = true;
+            NetworkVariableSerialization<T>.Duplicate(m_InternalValue, ref m_InternalOriginalValue);
             NetworkVariableSerialization<T>.Duplicate(m_InternalValue, ref m_PreviousValue);
         }
 
@@ -58,6 +59,7 @@ namespace Unity.Netcode
             : base(readPerm, writePerm)
         {
             m_InternalValue = value;
+            m_InternalOriginalValue = default;
             // Since we start with IsDirty = true, this doesn't need to be duplicated
             // right away. It won't get read until after ResetDirty() is called, and
             // the duplicate will be made there. Avoiding calling
@@ -76,6 +78,7 @@ namespace Unity.Netcode
             if (m_NetworkBehaviour == null || m_NetworkBehaviour != null && !m_NetworkBehaviour.NetworkObject.IsSpawned)
             {
                 m_InternalValue = value;
+                NetworkVariableSerialization<T>.Duplicate(m_InternalValue, ref m_InternalOriginalValue);
                 m_PreviousValue = default;
             }
         }
@@ -86,6 +89,12 @@ namespace Unity.Netcode
         [SerializeField]
         private protected T m_InternalValue;
 
+        // The introduction of standard .NET collections caused an issue with permissions since there is no way to detect changes in the
+        // collection without doing a full comparison. While this approach does consume more memory per collection instance, it is the
+        // lowest risk approach to resolving the issue where a client with no write permissions could make changes to a collection locally
+        // which can cause a myriad of issues. 
+        private protected T m_InternalOriginalValue;
+
         private protected T m_PreviousValue;
 
         private bool m_HasPreviousValue;
@@ -116,6 +125,7 @@ namespace Unity.Netcode
                 {
                     T previousValue = m_InternalValue;
                     m_InternalValue = value;
+                    NetworkVariableSerialization<T>.Duplicate(m_InternalValue, ref m_InternalOriginalValue);
                     SetDirty(true);
                     m_IsDisposed = false;
                     OnValueChanged?.Invoke(previousValue, m_InternalValue);
@@ -136,6 +146,17 @@ namespace Unity.Netcode
         {
             var isDirty = base.IsDirty();
 
+            // A client without permissions invoking this method should only check to assure the current value is equal to the last known current value
+            if (m_NetworkManager && !CanClientWrite(m_NetworkManager.LocalClientId))
+            {
+                // If modifications are detected, then revert back to the last known current value
+                if (!NetworkVariableSerialization<T>.AreEqual(ref m_InternalValue, ref m_InternalOriginalValue))
+                {
+                    NetworkVariableSerialization<T>.Duplicate(m_InternalOriginalValue, ref m_InternalValue);
+                }
+                return false;
+            }
+
             // Compare the previous with the current if not dirty or forcing a check.
             if ((!isDirty || forceCheck) && !NetworkVariableSerialization<T>.AreEqual(ref m_PreviousValue, ref m_InternalValue))
             {
@@ -166,6 +187,7 @@ namespace Unity.Netcode
             }
 
             m_InternalValue = default;
+            m_InternalOriginalValue = default;
             if (m_HasPreviousValue && m_PreviousValue is IDisposable previousValueDisposable)
             {
                 m_HasPreviousValue = false;
@@ -188,6 +210,13 @@ namespace Unity.Netcode
         /// <returns>Whether or not the container is dirty</returns>
         public override bool IsDirty()
         {
+            // If the client does not have write permissions but the internal value is determined to be locally modified and we are applying updates, then we should revert
+            // to the original collection value prior to applying updates (primarily for collections).
+            if (!NetworkUpdaterCheck && m_NetworkManager && !CanClientWrite(m_NetworkManager.LocalClientId) && !NetworkVariableSerialization<T>.AreEqual(ref m_InternalValue, ref m_InternalOriginalValue))
+            {
+                NetworkVariableSerialization<T>.Duplicate(m_InternalOriginalValue, ref m_InternalValue);
+                return true;
+            }
             // For most cases we can use the dirty flag.
             // This doesn't work for cases where we're wrapping more complex types
             // like INetworkSerializable, NativeList, NativeArray, etc.
@@ -199,11 +228,11 @@ namespace Unity.Netcode
                 return true;
             }
 
+            var dirty = !NetworkVariableSerialization<T>.AreEqual(ref m_PreviousValue, ref m_InternalValue);
             // Cache the dirty value so we don't perform this again if we already know we're dirty
             // Unfortunately we can't cache the NOT dirty state, because that might change
             // in between to checks... but the DIRTY state won't change until ResetDirty()
             // is called.
-            var dirty = !NetworkVariableSerialization<T>.AreEqual(ref m_PreviousValue, ref m_InternalValue);
             SetDirty(dirty);
             return dirty;
         }
@@ -221,6 +250,8 @@ namespace Unity.Netcode
             {
                 m_HasPreviousValue = true;
                 NetworkVariableSerialization<T>.Duplicate(m_InternalValue, ref m_PreviousValue);
+                // Once updated, assure the original current value is updated for future comparison purposes
+                NetworkVariableSerialization<T>.Duplicate(m_InternalValue, ref m_InternalOriginalValue);
             }
             base.ResetDirty();
         }
@@ -241,16 +272,20 @@ namespace Unity.Netcode
         /// <param name="keepDirtyDelta">Whether or not the container should keep the dirty delta, or mark the delta as consumed</param>
         public override void ReadDelta(FastBufferReader reader, bool keepDirtyDelta)
         {
-            // In order to get managed collections to properly have a previous and current value, we have to
-            // duplicate the collection at this point before making any modifications to the current.
-            m_HasPreviousValue = true;
-            NetworkVariableSerialization<T>.Duplicate(m_InternalValue, ref m_PreviousValue);
+            // If the client does not have write permissions but the internal value is determined to be locally modified and we are applying updates, then we should revert
+            // to the original collection value prior to applying updates (primarily for collections).
+            if (m_NetworkManager && !CanClientWrite(m_NetworkManager.LocalClientId) && !NetworkVariableSerialization<T>.AreEqual(ref m_InternalOriginalValue, ref m_InternalValue))
+            {
+                NetworkVariableSerialization<T>.Duplicate(m_InternalOriginalValue, ref m_InternalValue);
+            }
+
             NetworkVariableSerialization<T>.ReadDelta(reader, ref m_InternalValue);
 
-            // todo:
             // keepDirtyDelta marks a variable received as dirty and causes the server to send the value to clients
             // In a prefect world, whether a variable was A) modified locally or B) received and needs retransmit
             // would be stored in different fields
+            // LEGACY NOTE: This is only to handle NetworkVariableDeltaMessage Version 0 connections. The updated
+            // NetworkVariableDeltaMessage no longer uses this approach.
             if (keepDirtyDelta)
             {
                 SetDirty(true);
@@ -259,10 +294,43 @@ namespace Unity.Netcode
             OnValueChanged?.Invoke(m_PreviousValue, m_InternalValue);
         }
 
+        /// <summary>
+        /// This should be always invoked (client & server) to assure the previous values are set
+        /// !! IMPORTANT !!
+        /// When a server forwards delta updates to connected clients, it needs to preserve the previous dirty value(s)
+        /// until it is done serializing all valid NetworkVariable field deltas (relative to each client). This is invoked 
+        /// after it is done forwarding the deltas at the end of the <see cref="NetworkVariableDeltaMessage.Handle(ref NetworkContext)"/> method.
+        /// </summary>
+        internal override void PostDeltaRead()
+        {
+            // In order to get managed collections to properly have a previous and current value, we have to
+            // duplicate the collection at this point before making any modifications to the current.
+            m_HasPreviousValue = true;
+            NetworkVariableSerialization<T>.Duplicate(m_InternalValue, ref m_PreviousValue);
+            // Once updated, assure the original current value is updated for future comparison purposes
+            NetworkVariableSerialization<T>.Duplicate(m_InternalValue, ref m_InternalOriginalValue);
+        }
+
         /// <inheritdoc />
         public override void ReadField(FastBufferReader reader)
         {
+            // If the client does not have write permissions but the internal value is determined to be locally modified and we are applying updates, then we should revert
+            // to the original collection value prior to applying updates (primarily for collections).
+            if (m_NetworkManager && !CanClientWrite(m_NetworkManager.LocalClientId) && !NetworkVariableSerialization<T>.AreEqual(ref m_InternalOriginalValue, ref m_InternalValue))
+            {
+                NetworkVariableSerialization<T>.Duplicate(m_InternalOriginalValue, ref m_InternalValue);
+            }
+
             NetworkVariableSerialization<T>.Read(reader, ref m_InternalValue);
+            // In order to get managed collections to properly have a previous and current value, we have to
+            // duplicate the collection at this point before making any modifications to the current.
+            // We duplicate the final value after the read (for ReadField ONLY) so the previous value is at par
+            // with the current value (since this is only invoked when initially synchronizing).
+            m_HasPreviousValue = true;
+            NetworkVariableSerialization<T>.Duplicate(m_InternalValue, ref m_PreviousValue);
+
+            // Once updated, assure the original current value is updated for future comparison purposes
+            NetworkVariableSerialization<T>.Duplicate(m_InternalValue, ref m_InternalOriginalValue);
         }
 
         /// <inheritdoc />
@@ -270,5 +338,20 @@ namespace Unity.Netcode
         {
             NetworkVariableSerialization<T>.Write(writer, ref m_InternalValue);
         }
+
+        internal override void WriteFieldSynchronization(FastBufferWriter writer)
+        {
+            // If we have a pending update, then synchronize the client with the previously known
+            // value since the updated version will be sent on the next tick or next time it is
+            // set to be updated
+            if (base.IsDirty() && m_HasPreviousValue)
+            {
+                NetworkVariableSerialization<T>.Write(writer, ref m_PreviousValue);
+            }
+            else
+            {
+                base.WriteFieldSynchronization(writer);
+            }
+        }
     }
 }

Runtime/NetworkVariable/NetworkVariableBase.cs

@@ -251,6 +251,12 @@ namespace Unity.Netcode
             m_IsDirty = false;
         }
 
+        /// <summary>
+        /// Only used during the NetworkBehaviourUpdater pass and only used for NetworkVariable.
+        /// This is to bypass duplication of the "original internal value" for collections.
+        /// </summary>
+        internal bool NetworkUpdaterCheck;
+
         /// <summary>
         /// Gets Whether or not the container is dirty
         /// </summary>
@@ -341,6 +347,32 @@ namespace Unity.Netcode
         /// <param name="keepDirtyDelta">Whether or not the delta should be kept as dirty or consumed</param>
         public abstract void ReadDelta(FastBufferReader reader, bool keepDirtyDelta);
 
+        /// <summary>
+        /// This should be always invoked (client & server) to assure the previous values are set
+        /// !! IMPORTANT !!
+        /// When a server forwards delta updates to connected clients, it needs to preserve the previous dirty value(s)
+        /// until it is done serializing all valid NetworkVariable field deltas (relative to each client). This is invoked 
+        /// after it is done forwarding the deltas at the end of the <see cref="NetworkVariableDeltaMessage.Handle(ref NetworkContext)"/> method.
+        /// </summary>
+        internal virtual void PostDeltaRead()
+        {
+        }
+
+        /// <summary>
+        /// There are scenarios, specifically with collections, where a client could be synchronizing and
+        /// some NetworkVariables have pending updates. To avoid duplicating entries, this is invoked only
+        /// when sending the full synchronization information.
+        /// </summary>
+        /// <remarks>
+        /// Derrived classes should send the previous value for synchronization so when the updated value
+        /// is sent (after synchronizing the client) it will apply the updates.
+        /// </remarks>
+        /// <param name="writer"></param>
+        internal virtual void WriteFieldSynchronization(FastBufferWriter writer)
+        {
+            WriteField(writer);
+        }
+
         /// <summary>
         /// Virtual <see cref="IDisposable"/> implementation
         /// </summary>

Runtime/SceneManagement/SceneEventData.cs

@@ -320,9 +320,11 @@ namespace Unity.Netcode
         internal void AddSpawnedNetworkObjects()
         {
             m_NetworkObjectsSync.Clear();
+            // If distributed authority mode and sending to the service, then ignore observers
+            var distributedAuthoritySendingToService = m_NetworkManager.DistributedAuthorityMode && TargetClientId == NetworkManager.ServerClientId;
             foreach (var sobj in m_NetworkManager.SpawnManager.SpawnedObjectsList)
             {
-                if (sobj.Observers.Contains(TargetClientId))
+                if (sobj.Observers.Contains(TargetClientId) || distributedAuthoritySendingToService)
                 {
                     m_NetworkObjectsSync.Add(sobj);
                 }
@@ -666,12 +668,14 @@ namespace Unity.Netcode
             // Write our count place holder (must not be packed!)
             writer.WriteValueSafe((ushort)0);
             var distributedAuthority = m_NetworkManager.DistributedAuthorityMode;
+            // If distributed authority mode and sending to the service, then ignore observers
+            var distributedAuthoritySendingToService = distributedAuthority && TargetClientId == NetworkManager.ServerClientId;
 
             foreach (var keyValuePairByGlobalObjectIdHash in m_NetworkManager.SceneManager.ScenePlacedObjects)
             {
                 foreach (var keyValuePairBySceneHandle in keyValuePairByGlobalObjectIdHash.Value)
                 {
-                    if (keyValuePairBySceneHandle.Value.Observers.Contains(TargetClientId))
+                    if (keyValuePairBySceneHandle.Value.Observers.Contains(TargetClientId) || distributedAuthoritySendingToService)
                     {
                         // Serialize the NetworkObject
                         var sceneObject = keyValuePairBySceneHandle.Value.GetMessageSceneObject(TargetClientId, distributedAuthority);

Runtime/Spawning/NetworkSpawnManager.cs

@@ -72,11 +72,22 @@ namespace Unity.Netcode
                     return;
                 }
             }
+
             foreach (var player in m_PlayerObjects)
             {
-                player.Observers.Add(playerObject.OwnerClientId);
-                playerObject.Observers.Add(player.OwnerClientId);
+                // If the player's SpawnWithObservers is not set then do not add the new player object's owner as an observer.
+                if (player.SpawnWithObservers)
+                {
+                    player.Observers.Add(playerObject.OwnerClientId);
+                }
+
+                // If the new player object's SpawnWithObservers is not set then do not add this player as an observer to the new player object.
+                if (playerObject.SpawnWithObservers)
+                {
+                    playerObject.Observers.Add(player.OwnerClientId);
+                }
             }
+
             m_PlayerObjects.Add(playerObject);
             if (!m_PlayerObjectsTable.ContainsKey(playerObject.OwnerClientId))
             {
@@ -423,8 +434,31 @@ namespace Unity.Netcode
             ChangeOwnership(networkObject, NetworkManager.ServerClientId, true);
         }
 
+        private Dictionary<ulong, float> m_LastChangeInOwnership = new Dictionary<ulong, float>();
+        private const int k_MaximumTickOwnershipChangeMultiplier = 6;
+
         internal void ChangeOwnership(NetworkObject networkObject, ulong clientId, bool isAuthorized, bool isRequestApproval = false)
         {
+            // For client-server:
+            // If ownership changes faster than the latency between the client-server and there are NetworkVariables being updated during ownership changes,
+            // then notify the user they could potentially lose state updates if developer logging is enabled.
+            if (!NetworkManager.DistributedAuthorityMode && m_LastChangeInOwnership.ContainsKey(networkObject.NetworkObjectId) && m_LastChangeInOwnership[networkObject.NetworkObjectId] > Time.realtimeSinceStartup)
+            {
+                var hasNetworkVariables = false;
+                for (int i = 0; i < networkObject.ChildNetworkBehaviours.Count; i++)
+                {
+                    hasNetworkVariables = networkObject.ChildNetworkBehaviours[i].NetworkVariableFields.Count > 0;
+                    if (hasNetworkVariables)
+                    {
+                        break;
+                    }
+                }
+                if (hasNetworkVariables && NetworkManager.LogLevel == LogLevel.Developer)
+                {
+                    NetworkLog.LogWarningServer($"[Rapid Ownership Change Detected][Potential Loss in State] Detected a rapid change in ownership that exceeds a frequency less than {k_MaximumTickOwnershipChangeMultiplier}x the current network tick rate! Provide at least {k_MaximumTickOwnershipChangeMultiplier}x the current network tick rate between ownership changes to avoid NetworkVariable state loss.");
+                }
+            }
+
             if (NetworkManager.DistributedAuthorityMode)
             {
                 // If are not authorized and this is not an approved ownership change, then check to see if we can change ownership
@@ -497,15 +531,21 @@ namespace Unity.Netcode
             // Always notify locally on the server when ownership is lost
             networkObject.InvokeBehaviourOnLostOwnership();
 
-            networkObject.MarkVariablesDirty(true);
-            NetworkManager.BehaviourUpdater.AddForUpdate(networkObject);
-
             // Authority adds entries for all client ownership
             UpdateOwnershipTable(networkObject, networkObject.OwnerClientId);
 
             // Always notify locally on the server when a new owner is assigned
             networkObject.InvokeBehaviourOnGainedOwnership();
 
+            if (networkObject.PreviousOwnerId == NetworkManager.LocalClientId)
+            {
+                // Mark any owner read variables as dirty
+                networkObject.MarkOwnerReadVariablesDirty();
+                // Immediately queue any pending deltas and order the message before the
+                // change in ownership message.
+                NetworkManager.BehaviourUpdater.NetworkBehaviourUpdate(true);
+            }
+
             var size = 0;
             if (NetworkManager.DistributedAuthorityMode)
             {
@@ -569,6 +609,17 @@ namespace Unity.Netcode
             /// This gets called specifically *after* sending the ownership message so any additional messages that need to proceed an ownership
             /// change can be sent from NetworkBehaviours that override the <see cref="NetworkBehaviour.OnOwnershipChanged"></see>
             networkObject.InvokeOwnershipChanged(networkObject.PreviousOwnerId, clientId);
+
+            // Keep track of the ownership change frequency to assure a user is not exceeding changes faster than 2x the current Tick Rate.
+            if (!NetworkManager.DistributedAuthorityMode)
+            {
+                if (!m_LastChangeInOwnership.ContainsKey(networkObject.NetworkObjectId))
+                {
+                    m_LastChangeInOwnership.Add(networkObject.NetworkObjectId, 0.0f);
+                }
+                var tickFrequency = 1.0f / NetworkManager.NetworkConfig.TickRate;
+                m_LastChangeInOwnership[networkObject.NetworkObjectId] = Time.realtimeSinceStartup + (tickFrequency * k_MaximumTickOwnershipChangeMultiplier);
+            }
         }
 
         internal bool HasPrefab(NetworkObject.SceneObject sceneObject)
@@ -695,14 +746,14 @@ namespace Unity.Netcode
         /// Gets the right NetworkObject prefab instance to spawn. If a handler is registered or there is an override assigned to the 
         /// passed in globalObjectIdHash value, then that is what will be instantiated, spawned, and returned.
         /// </summary>
-        internal NetworkObject GetNetworkObjectToSpawn(uint globalObjectIdHash, ulong ownerId, Vector3 position = default, Quaternion rotation = default, bool isScenePlaced = false)
+        internal NetworkObject GetNetworkObjectToSpawn(uint globalObjectIdHash, ulong ownerId, Vector3? position, Quaternion? rotation, bool isScenePlaced = false)
         {
             NetworkObject networkObject = null;
             // If the prefab hash has a registered INetworkPrefabInstanceHandler derived class
             if (NetworkManager.PrefabHandler.ContainsHandler(globalObjectIdHash))
             {
                 // Let the handler spawn the NetworkObject
-                networkObject = NetworkManager.PrefabHandler.HandleNetworkPrefabSpawn(globalObjectIdHash, ownerId, position, rotation);
+                networkObject = NetworkManager.PrefabHandler.HandleNetworkPrefabSpawn(globalObjectIdHash, ownerId, position ?? default, rotation ?? default);
                 networkObject.NetworkManagerOwner = NetworkManager;
             }
             else
@@ -752,8 +803,10 @@ namespace Unity.Netcode
                 }
                 else
                 {
-                    // Create prefab instance
+                    // Create prefab instance while applying any pre-assigned position and rotation values
                     networkObject = UnityEngine.Object.Instantiate(networkPrefabReference).GetComponent<NetworkObject>();
+                    networkObject.transform.position = position ?? networkObject.transform.position;
+                    networkObject.transform.rotation = rotation ?? networkObject.transform.rotation;
                     networkObject.NetworkManagerOwner = NetworkManager;
                     networkObject.PrefabGlobalObjectIdHash = globalObjectIdHash;
                 }