God
Press ' to bring up the Console Window. Enter the following cheats turn on either Avatar God Mode (only the player you are controlling is invincible) or Team God Mode.

Avatar God Mode = avatargod
Team God Mode = teamgod

Characters
Press ' to bring up the Console Window. Enter the following codes in to turn on the corresponding cheat.

Big Head Mode = bignoggin
Mega Head Mode = meganoggin
Big chests when breathing = 1-900
Big hands and feet = clodhopper
Stumpy Models = stumpy
2D Models = turnpunchkick

Invisibility
Press ' to bring up the Console Window. Enter the following cheats turn on either Single Invisibility Mode (only the player you are controlling is invisible) or Team Invisibility Mode.

Single Invisibility Mode = theshadowknows
Team Invisibility Mode = teamshadow

NOTE: ''Invisible'' means that the AI characters (terrorists and hostages) cannot see you, however, you can still see the character models.

Inventory
Press ' to bring up the Console Window. Enter ''5fingerdiscount'' to refill your inventory.

Turn of victory conditions
Press ' to bring up the Console Window. Enter ''explore'' to disable the victory conditions of the mission (ie: terrorists killing hostages will not end your mission).