TI Multiplayer/Mod Compatibility

This page is part of the TI Multiplayer mod.

TI Multiplayer runs the whole game on the host and copies the result to the other players. A mod that adds its own player actions or its own game data must know about this, or its changes only happen on one computer. Such multiplayer-aware mods connect to TI Multiplayer through a small interface (the mod bridge).

For players

Multiplayer-aware mods

Mod	Notes
TI Fleet Manager	All fleet hierarchy commands, recalls, commissioning and reserve operations are carried out by the host. Generated fleet names use the host's game language.
TI Space Nations	Founding nations, unions, settlement, troop transports, the AI and the aliens run on the host. Only the host's settings count.
TI Missile Rework	Missile design actions are carried out by the host.

Rules

• Every player needs the same multiplayer-aware mods in the same versions. This is checked when joining a lobby, when joining a running game and when reconnecting. A difference is refused with Your loaded mods do not match the host's. and a list of what is missing or extra on each side.
• Mods that only change game data (JSON templates, texts, images) are not checked. Make sure everybody installs exactly the same ones - different data leads to desyncs.
• Other code mods (DLL mods without the bridge) are not supported in multiplayer and can cause problems. TI Crew Extended, for example, has no multiplayer support.

DLC

A host who owns a DLC can host the base game for players without it. They see fallback models for DLC ship hulls. A scenario that requires a DLC (for example the Dark Skies scenarios) needs it on every computer - players without it are refused with This campaign requires content you don't have: ….

For mod authors

The bridge is the class TIMultiplayer.Sync.MPModBridge (API version 1). Use it only through reflection - never reference the TIMultiplayer DLL directly, so your mod also runs without it. Load order is not guaranteed: look the type up from the main menu with a short retry (for example every second for 30 seconds).

Member	Use
InSandboxSession, IsHost, IsRemoteClient	Session state. Skip everything your mod changes on its own (daily ticks, repairs after loading, reactions to removed objects) when IsRemoteClient is true - the host does it and sends the result.
RegisterForwardedAction(typeFullName, mode)	Register a player action type that must be sent to the host. Mode 0 = forward only, mode 1 = forward and also run locally. Register on every computer at load. Anything that can create game objects must be forward-only. Action fields must be plain values. Delegates arrive as null on the host.
RegisterOperationPolicy(opTypeFullName, runLocal)	For fleet or hab operations confirmed through the vanilla operation dialog.
RequestBroadcast(ids, reason)	The host pushes changed objects to the clients within about a second.
event MergeApplied(bool fullSave)	Fires on clients after the host's update was applied - refresh your UI here.
RegisterModIdentity(modId, version)	Adds your mod to the join check. Even data-only mods should register through a tiny loader, so mismatches are caught.
ForwardingFaction (since 0.8.0)	The faction whose forwarded command the host is applying right now, otherwise null. While it is set, your mod's actions should refuse to touch another faction's entities. The host itself already drops a forwarded operation whose actor (fleet, hab or army) does not belong to the sender. Look the property up optionally, older versions do not have it.

Further rules: custom game-state types should set their owning faction, and always test with two game instances. TI Fleet Manager, TI Space Nations and TI Missile Rework are working examples of the bridge.

See also

• Mods - community mods
• Modding