testland/multiplayer-state-machine-coverage
Use before a multiplayer game goes to platform cert, where broken multiplayer is a common rejection. Builds a coverage matrix for connect, authority handoff, disconnect, reconnect and host migration under latency, loss and reordering for Unity Netcode, Unreal and Mirror, with a go/no-go gate.
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engine-states.mdreferences/
Networked engine state and ownership tables - reference
Per-engine connection-state and authority-state enumerations for multiplayer-state-machine-coverage Steps 1-2. The matrix is fixed by each framework - you cannot add or remove states, only choose which to cover.
Connection states
Unity Netcode for GameObjects (per the v2.11 manual):
| State | Trigger | Observability |
|---|---|---|
Disconnected | Initial / after disconnect | NetworkManager.IsConnectedClient == false |
Connecting | NetworkManager.StartClient() invoked | Between request and approval |
Connected (Approved) | Server accepts client | OnClientConnectedCallback |
Connected (Pending Spawn) | Approved but player object not yet spawned | Wait for OnNetworkSpawn |
Connected (Spawned) | NetworkObject.IsSpawned == true | Gameplay-ready |
Disconnecting | Shutdown() / link loss | OnClientDisconnectCallback fires next |
Host | Same process is both server + client | NetworkManager.IsHost |
Unreal Engine replication (per the Networking Overview):
| State | Trigger | Observability |
|---|---|---|
NM_Standalone | Single-player | World->GetNetMode() |
NM_DedicatedServer | "Separate machine with no local players" | IsRunningDedicatedServer() |
NM_ListenServer | "Host machine where the server operator also plays locally" | IsRunningListenServer() |
NM_Client | Connected as remote client | World->IsClient() |
Login | AGameModeBase::PreLogin → Login → PostLogin | Override PostLogin |
Travel (seamless / hard) | ServerTravel to new map | PlayerController->bIsClientReplicationPausedForFrame |
Logout | Logout() callback | Override on GameModeBase |
Mirror Networking (per the Mirror docs on NetworkBehaviour):
| State | Trigger | Observability |
|---|---|---|
OnStartServer | "called on server when a game object spawns on the server" | NetworkBehaviour override |
OnStartClient | "called on clients when the game object spawns on the client" | NetworkBehaviour override |
OnStartLocalPlayer | Local player only, after OnStartClient | NetworkBehaviour override |
OnStartAuthority / OnStopAuthority | "Called when ownership changes" | NetworkBehaviour override |
OnStopServer / OnStopClient | "Cleanup when objects are destroyed" | NetworkBehaviour override |
Ownership / authority states
| Engine | Authority states |
|---|---|
| Unity NGO | OwnerClientId (per NetworkObject); IsOwner, IsServer, IsHost flags |
| Unreal | ROLE_Authority (server), ROLE_AutonomousProxy (owning client), ROLE_SimulatedProxy (other clients), ROLE_None |
| Mirror | isServer, isClient, isLocalPlayer, isOwned per Mirror NetworkBehaviour docs - isOwned "Returns true on the client if this client has authority over this game object" |