Press the TILDE key(~)during game play to bring up the cosole screen then type any of these followed by a carrige return.

To find out other codes, type some letters and then the TAB key. Once TAB is pressed, the cosole will try to finish what you were typing.

GOD (god mode)

IMPULSE 1 or IMPULSE 255 (quad damage)

IMPULSE 9 (all weapons,ammo,and keys)

IMPULSE 11 (gives one rune:type four times to get all four)

REGISTERED 1 (makes the computer think you have the registered version:Thunderbolt available)

CROSSHAIR (add crosshairs on the screen)

NOCLIP (no clipping mode:use D and C to go up and down)

FLY (fly mode:use D and C to go up and down)

NOTARGET (enemis will not target you)

SV_GRAVITY[##] (sets the gravity in the level to ##:from 0 to 850)

MAPE[episode]M[level] (warps you to desired level)

HEALTH[##] (gives ## health:from 0 to 999)

GIVE 2 (gives Shotgun)

GIVE 3 (gives Double barreled shotgun)

GIVE 4 (gives Nailgun)

GIVE 5 (gives Super nailgun)

GIVE 6 (gives Grenade Launcher)

GIVE 7 (gives Missile Launcher)

GIVE 8 (gives Thunderbolt)

GIVE S (gives ## shotgun shells:can be from 0 to 255)

GIVE N (gives ## nails:can be from 0 to 255)

GIVE R (gives ## rockets:can be from 0 to 255)

GIVE C (gives ## battery charges:can be from 0 to 255)