Doom · PC · 1993 · Cheat Code
Effect: Gives the player all weapons, full ammunition, all keys, and full armour.
IDKFA — which id Software staff jokingly expanded to "ID Keys, Full Ammo" — was one of the original cheat codes shipped with Doom and quickly became the go-to shortcut for players who wanted to experience combat with the full arsenal from the start. A companion code, IDFA, provides all weapons and ammo but no keys, making IDKFA the more complete variant. Together with IDDQD, these two codes defined the cheat-code culture of 1990s PC gaming and were memorised by a generation of players.