To activate a cheat, press the tilde key [~] and enter its corresponding code at the system command console.

allammo	Ammo, guns
amphibious	Breathe Underwater
god	Invincible
fly	Fly mode
walk	Walk mode
ghost	Walk through walls
playersonly	Stop Time
invisible 1	Be invisible
invisible 0	Be visible
killall	Kill all monsters of a type
killpawns	Kill all monsters
say	Send message to other players
slomo	Gamespeed. Normal is 1.0
switchcooplevel	Select Coop level
switchlevel	Change levels
summon	Get monster of a certain class