Start the game with the command-line parameter:

+set ui_console 1 +set cheats 1 +set thereisnomonkey 1

Then during a single-player game, press ~ for the console and type any of the following "Codes":

Code - Effect

listinventory - List Inventory
tele x y z - Teleport to Location x y z
coord - Shows Location
health - Set Current Health
kill - Kills Player

giveweapon weapons/(weapon_name).tik - Gives Player (weapon_name)

Weapon - Names

Colt 45 - colt45
Frag Grenade - m2frag_grenade
Walther P38 - p38
Steilhandgranate - steilhandgranate
M1 Garand - m1_garand
Mauser KAR 98K - kar98
Shotgun - shotgun
Bazooka - bazooka
Panzerschreck - panzerschreck
BAR - bar
StG 44 - mp44
Thompson - thompsonsmg
MP40 - mp40
Springfield '03 Sniper - springfield
KAR98 Sniper - kar98sniper

Start the game with the command-line parameter:

+set ui_console 1 +set cheats 1 +set thereisnomonkey 1

Then during a single-player game, press ~ for the console and type any of the following "Codes":

Code - Effect

dog - God Mode
fullheal - Full Health
wuss - All Weapons and Ammo
noclip - No Clipping
notarget - Show Game Version