Updated 17 August, 2017
All commands are typed in in-game chat and begin with a / Commands have access levels and won't work for you if your level is too low.
Note: There are actually commands missing from this list and a few commands are deliberately undocumented. Those commands don't do anything profound. They are there for you to discover in the code as a reward for reading it.
/bounty
See the player kills and current bounty on a player's head.
/gimme peace
All gimme messages will be private messages.
/fix gimme
Force the bot to rescan the list of zombies and animals.
/reset gimmehell
Cancel a gimmehell game in progress.
/gimme reset
Reset gimme counters for everyone so they can play gimme again. The bot does this every 2 hours automatically.
/gimme gimme
All gimme messages will be in public chat.
/gimme off
Disable the gimme game.
/gimme on
Enable the gimme game.
/gimme zombies
Players can win zombies.
/gimme no zombies
Gimme prizes will not include zombies.