Doom2 Cheats
IDDQD - Degreelessness mode (the god code)
IDCLIP - No clipping mode (you walk through walls)
IDFA - All weapons, full ammo, and 200% armor
IDKFA - All weapons, full ammo, 200% armor, and all the keys
IDDT - You must first be viewing the map then type it, 1st time-full map, 2nd time-shows all the guys
IDCHOPPERS - Prints "Doesn't suck" on the screen, then gives you the chainsaw
IDCLEV#@ - Warps you to episode (#), level (@)
IDMYPOS - Displays your exact cordinates in Hex format
IDBEHOLS# - Replace (#) with one of the fallowing letters (all tremperary)
    R - Radiation protection suit
    I - Invisiblity (speckly, same as those mosters
    V - Invulnerability
    A - Full map
    L - Lights up the level
    S - Berserker mode (fun)
IDMUS#@ - Changes the music to the that from episode (#), level (@)
During multiplayer co-op games
T[ALT]IDDT - Press T to get to the map screen, then hold down [ALT] and type IDDT several times (you can see where your enemies are)


Doom Cheats
IDDQD - Degreelessness mode (the god code) 
IDSPISPOPD - No clipping mode (you walk through walls) 
IDFA - All weapons, full ammo, and 200% armor 
IDKFA - All weapons, full ammo, 200% armor, and all the keys 
IDDT - You must first be viewing the map then type it, 1st time-full map, 2nd time-shows all the guys 
IDCHOPPERS - Prints "Doesn't suck" on the screen, then gives you the chainsaw 
IDCLEV#@ - Warps you to episode (#), level (@) 
IDMYPOS - Displays your exact cordinates in Hex format
IDBEHOLS# - Replace (#) with one of the fallowing letters (all tremperary)
    R - Radiation protection suit 
    I - Invisiblity (speckly, same as those mosters 
    V - Invulnerability 
    A - Full map
    L - Lights up the level
    S - Berserker mode (fun)
IDMUS#@ - Changes the music to the that from episode (#), level (@)