Key



Keys are used to open designated locked doors. There are two types of key; futuristic keycards, and "skull keys" which resemble glowing monochrome skulls. If the player encounters a locked door and attempts to open it without the correct key, the door will not open (and the player will get a message to that effect). Once a key is obtained, any locked door of the corresponding color on the map can be opened. All keys are lost upon exiting a map.

Multiple keys of a given color may be picked up in the same level; the status bar will display whichever type was last taken. Doors in Doom are affected identically by keycards and skull keys. Boom, however, introduced door types that require the key to be of the right type and not just the right color; such doors are supported in most source ports. Certain source ports also allow the use of locked doors requiring multiple keys.

Final Doom introduced "locked" switches, which cannot be activated without a key of the appropriate color.

In multiplayer deathmatch games, all keys are removed from each map, and players spawn carrying all keys.

Appearance statistics
The IWADs contain the following numbers of keys: Blue keycard

Red keycard Yellow keycard

Blue skull key Red skull key Yellow skull key