Add the “+set developer 1 +set sv_cheats 1” command line parameter. Press ~ during game play to bring down the console window.

• Spawn item: give (item)
• Full health: give health
• Save game: savegame
• Load saved game: loadgame
• Get all items: give all
• Ammunition: give ammo
• Invincibility: god
• Ignored by enemy: notarget
• No clipping: noclip
• Fly mode: ufo
• Teleport to a specific map node jumptonode
• Play indicated map: map (map name)
• Suicide: kill