Two related questions:
Can you create new NPCs during play? My understanding is that you can’t and that the NPCs must exist before the game starts, even if they’re inactive. But I’m not certain.
Can you change an NPC’s properties during play? Could you have a “blank” NPC whose properties are set on activation? If you can, is this limited to just descriptions? Or can you change more complex things like NPC dialogue, scheduling, etc?