Press ~ during game play to display the console window. Type login developer to enable cheat mode. Note: The character "#" will be displayed instead of the letters in "developer". Then, activate the following cheats by entering the corresponding codes:
CHEAT FUNCTION - CHEAT CODE Flight mode - fly 1 All weapons with unlimited ammo - unammo God mode - god 1
Note: This procedure requires editing a game file; creating a backup copy of the file before proceeding is recommended. With a text editor, edit the "weapons.god" file in the game folder. The ammunition count and other settings can now be altered. Edit the "armour.god" file in the same folder to get better armor.