Bukkit

We have set up the arena for 'Ultimate survival games' and it seems to work well except for the fact that we can't be damaged. Do you know what the problem could be? Is there a command somewhere that needs adjusting?

You could try allowing PvP in your Multiverse world (If you use Multiverse), if you have a region in the survival games, use flag /region flag pvp RegionName allow. And if those don't work, you could enable pvp from the server properties file, although then the whole server would have pvp enabled unless you make regions with WorldGuard.

Same issue, I start a game, players cannot take damage and world guard is configured properly.

@DrHeadoff: Go

Same here. Did you find a solution? Thanks!