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@@ -55,6 +55,38 @@ The main toolkit module [`RWTHVRToolkit`](https://git-ce.rwth-aachen.de/vr-vis/V
 
 ### GamePlay Framework
 
+The gameplay framework currently consists of the following extensions:
+
+1. `RWTHVRGameMode`
+2. `RWTHVRPlayerState`
+3. `BP_VirtualRealityPawn`
+
+**1. `RWTHVRGameMode`**
+
+The `RWTHVRGameMode` blueprint is based on the `RWTHVRGameModeBase` C++ class, which in turn inherits from [`AGameModeBase`](https://docs.unrealengine.com/5.3/en-US/API/Runtime/Engine/GameFramework/AGameModeBase/).
+
+It controls the flow of the application and handles new players and the corresponding default classes. **It is important to notice that it only exists on the server, not on any clients!**
+The `RWTHVRGameMode` blueprint sets the following defaults:
+
+- Default Pawn: `BP_VirtualRealityPawn`
+- Default Player State: `RWTHVRPlayerState`
+
+Additionally, it overrides the `InitNewPlayer` function to check for specific join options in the Join-Session string that new clients send to the server on initial connection. This happens when nDisplay nodes join a server. We need to identify those here to spawn a dummy spectator pawn for all the secondary nodes, and only a regular default pawn for the primary nDisplay node. 
+
+In case a primary/secondary node is identified by the connection string, the Game Mode sets the corresponding player type on the new player's `RWTHVRPlayerState`.
+
+In the `PostLogin` override, the player type is then queried and the correct pawn spawned and possessed. 
+
+**2. `RWTHVRPlayerState`**
+
+The `RWTHVRPlayerState` is a simple extension of [`APlayerState`](https://docs.unrealengine.com/5.3/en-US/API/Runtime/Engine/GameFramework/APlayerState/). It extends the basic class by adding support for a replicated PlayerType variable, which stores the corresponding player's (hardware) type, and can be one of the following: `nDisplayPrimary`, `nDisplaySecondary`, `Desktop`, `HMD`.
+
+For now, it is set to the first two in case the GameMode notices a corresponding connection string for the connecting client, or in the Pawn in case of standalone mode or the latter two types.
+
+**3. `BP_VirtualRealityPawn`**
+
+As the Pawn is more involved, it gets its own [Pawn](#Pawn) section below.
+
 ### Pawn
 
 ### Replication