In KSP 1.2.2 there is an extension for GameEvents that allows mods to register their own GameEvents and for any Mod to find and register a callback for said GameEvents. How to use (example): Define your GameEvent as a static in Mod A: public static EventData<Part, ProtoCrewMember> onKerbalFrozen; and Initialize it somewhere early before ModB tries to find and register it. onKerbalFrozen = new EventData<Part, ProtoCrewMember>("onKerbalFrozen"); Find th