PARTIAL SAVE: writes ONLY the 'Multiplayer' field of TitlePublicConfigurationModel; all other v1/v2 fields stay untouched. Realtime multiplayer (WebRTC peer-to-peer) - the engine is only the signaling server: it creates rooms, relays WebRTC offer/answer/ICE between room members and optionally relays lobby chat; game traffic then flows directly between players' browsers and never touches the server. The section is ABSENT by default, which means multiplayer is DISABLED: add it (SystemState.Enabled = true) to turn the Multiplayer module on. DefaultTopology: Mesh (everyone connects to everyone, 2-4 players) or Host (star: every player connects to the host, which runs the authoritative game simulation - required by host-authoritative games such as VoxelCraft). MaxPlayersPerRoom is a hard cap (default 8). MemberTimeoutMs is also how long a silent host keeps the host role before another member may take it over. IceServers are PUBLIC: list only STUN servers there; short-lived TURN credentials are issued by the engine to room members on create/join.