Here is what you could do...I think it would work: Keep it public. Build within your house a "safe area". Like a place within double walls where poison fields and stuff cant reach you on the first floor and keep a friended or co-owned character in there. Make a series of teleporters on the first floor that one has to follow before they can even reach the second floor or whichever one the tourney is being held on. (like surround each teleporter by walls or a bar tile and maybe make its three tiles long so you have to take a couple tiles to step on the next teleporter in the sequence.) That way the person in the safe spot can keep banning the BC members as they try to navigate the teleporter maze.