With that definition of “state”, you actually mean “a helluva variables”, or some fewer variables that, at load stage, other systems can query to set up relevant actors when BeginPlay event is raised (i.e. your save system stores scene state to specifiy designed AI pawns to execute specific BTs). A complete snapshot, like those in some emulators sounds more like you’re trying to achieve. I don’t know any other way to get it done besides Ninjin’s answer.