Type any of these cheats at the console for their effects.
(note: to access the console press the tilde key during play
Weapons and Ammo cheats:
give all
give shotgun
give shells
give sshotgun
give machinegun
give bullets
give grenade launcher
give grenades
give rocket launcher
give rockets
For health type: give health
For invincibility type: god
For no clipping type: no clip