Instanced minigames, pmod room (was that before construction?)
What kind of minigames?
afaik the 'common' example I read about was the fight pits, but it could be that way for any instanced minigame (pc, barb assault)
Then again we can't really go back and time and see how they did it. and we all know that if you do it right you can just use the height*4 trick to get new instances