You could just build no-rendered walls around the area you want them to stay in, then event the wall to kill anyone that touches it.
The problem with this is if the area is too big, you end up using quite a few bricks, which will eventually make people lag.
look for the oxygen mod!
A playertype that dies in water
Quote: look for the oxygen mod!Quote: A playertype that dies in water
Player_NoSwimming.zip