While playing a game, press ~ to display the console window. Then, enter one of the following codes to activate the corresponding cheat function. Note: Not all codes work in all versions of the game.
Result
Cheat Code
Invincibility free lives
All guns and maximum ammunition giveall();
Toggle enemy God mode aigodmode [0 or 1]
Toggle protectee God mode aiprotectprotectee [0 or 1]
Toggle God mode god [0 or 1]
Toggle enemy AI cannot hear you aidisableears [0 or 1]
Toggle enemy AI cannot see you aidisableeyes [0 or 1]
Toggle flight mode and no clipping noclip [0 or 1]