Key



A key is an item used to open designated locked doors or switches.

Description
E1m2redkey.png There are two types of key: electronic 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 receive 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 vanilla Doom are affected identically by keycards and skull keys. In stock maps, as a cosmetic guideline, a bar of coloured lights surround a locked door when keycards are used, while a column of coloured skulls are used for skull keys. (However, this is occasionally violated, such as in E2M3: Refinery which had keycard pickups but skull doorframes.)

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

Keys first appear in E1M2: Nuclear Plant, and reappear in almost every level except for E3M1: Hell Keep, MAP01: Entryway, and MAP07: Dead Simple.

Enhancements

 * Ultimate Doom and Final Doom introduced "locked" switches, which cannot be activated without a key of the appropriate color. The feature, however, was limited only to buttons that open fast doors permanently. Such switches were already supported in Doom II but the level designers never used them in the game, except as "locked fast open door" without a "switch".


 * Boom 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, a situation sometimes approximated in the original games by placing several locked doors in front of each other (e.g. E2M6: Halls of the Damned). Another notable example of this phenomenon appears in MAP29: For We Are Many of Community Chest 3: the door to the level exit has all three skull key indicators flanking it, and the message, "You need all three keys to open this door," will appear if a player who does not possess all three keys tries to open the door. MAP19: The Citadel has a feature where the exit has three shafts, each with a different key type however in this case only 2 certain shafts of the three need to be opened as opposed to all three. MAP09: Abattoire also has that feature, but only the red keycard shaft needs to be opened. All three keys are still required in this case.


 * Doom 64 introduced a key-activated, or "locked", tripwire in MAP30: The Lair; the player needs to be in possession of the yellow key and pass through the tripwire in order to lower a switch on the wall. If the player does not possess the key the switch will not lower, the Marine will "Mmmph!" and the line "You Need The Yellow Key" will appear on the top of the screen.

Data






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

Doom RPG
Keycards appear in Doom RPG, but skull keys do not.