Doom 2: Hell On Earth Codes -

Network cheat mode:
Hold [Alt] and type iddtiddtiddtiddt in map mode.

Deathmatch cheat mode:
Type t in the map to enter talk mode. Hold [Alt] and type iddt several times. This will reveal the entire map. Repeat the code to reveal all items. Repeating the code again will return the map to normal.

Permanent turbo:
Start the game with the doom2 -turbo 250 command line to have your player in turbo for the entire game.

Wolfenstein:
Type idclev32 or idclev31 during game play to restart in a totally new level. When you complete one of those levels you will always start on the level suburbs and continue your Doom 2 game.

Cheat mode:
Enter one of the following codes during game play to activate the corresponding cheat function.

Effect	Code
Invincibility	iddqd
All weapons, keys, ammo, and 200% armor	idkfa
Reset ammunition	idfa
Berserker strength	idbeholds
Temporary invincibility	idbeholdv
Temporary invisibility	idbeholdi
Full automap	idbeholda
Anti-radiation suit	idbeholdr
Light amplification visor	idbeholdl
Walk through walls	idclip
Chainsaw	idchoppers
Level select	idclev<level number 01-32>
Toggle full map; full map and objects; normal map	iddt
Display coordinates and heading	idmypos
Change music to indicated level	idmus<level number 01-32>

Hint: Romero's head:
At the final level, type idclip to enable the "Walk through walls" code. Go through the wall with the demon head on it. You will see that the final boss is the head of John Romero, the co-creator of the Doom series.

Hint: Backwards sound:
If you play the challenge made by the final boss backwards, you will hear him say "To win the game you must kill me, John Romero".