Type the following codes in during gameplay:
iddqd-god mode
idkfa-gives all keys, weapons, and ammo
idfa-gives all weapons and ammo (Doom 2 only)
iddt-toggle map mode (use when looking at map)
idclevxy-change level to episode x, level y (Doom),
or, in Doom 2, warp to level
xy(01-32)
idclip-toggles no clipping mode (Doom
2 only)
idspispopd-toggles no clipping mode (Doom only)
idbeholdi-invisiblity sphere
idbeholds-berserk pack
idbeholdv-invulnerability sphere
idbeholdr-radiation suit
idbeholda-full map
idbeholdl-light amplification visor
idmusxx-change music to that in level xx (Doom 2 only)
Network Cheat: Hold ALT and type IDDT 4 times while in map mode.