The following cheats are for 1 player games only. To use them, start a normal game on any episode with any difficulty but the highest, and type them in. You will not see the letters on the screen so if it doesn't work try again. Letter case doesn't matter.

Dukematch Cheats? Contrary to popular belief (of newbies), there is no way to become invincible, invisible, super strong, or otherwise in a Dukematch. There is, however, one cheat that can be exploited in a Dukematch game. First, start duke with the "/r" option or manually turn on record in the options menu once you start. Once you start the game and are playing, hit the coop view, default is "k". You will be able to see through your opponent(s) eyes! This will allow you to see where he is, how much health and armor he has, what weapon, how much ammo, etc.! This is most useful right after a kill since you can find/kill him before he powers up. After a match, you can start a 1 player game of duke and watch the demo from a 3rd person perspective or through the eyes of either player(hit the coop view to change). Its good to see your mistakes and find ways to improve. This is cheating and not appreciated by most players, so try not to use it. Don't even try to use it in a small level like "Stadium" or an open user level like "Army.map". It is useless there.