Press ~ to display the console during the game and then enter one of the following codes to activate the corresponding cheat function:
God mode: god
All spells: allammo
No clipping mode: ghost
Fly mode: fly
Walk mode: walk
Enable invisibility: invisible 1
Disable invisibility: invisible 0
Third person view: behindview 1
Normal view: behindview 0
Toggle time on and off: playersonly
Kill all monsters: killpawns
Kill indicated classes: killall [class]
Summon indicated class: summon [class]
Select new coop level: switchcooplevel [level]
Level select: switchlevel [level]
Set game speed: slomo [0.0-1.0]
Sends message to other players: say [message]