Doom Eternal keys

A number of keys are found in Doom Eternal and its expansions.

Slayer Keys
One Slayer Key is found in every level that includes a Slayer Gate; they are usually placed near the gate's location and are the only way to open the gate. Slayer Keys are large and have a cross-shaped blade, and bear the Doom Slayer's mark; they also give off a purple aura before being picked up.

Slayer Keys are hidden when using cheat codes.

Empyrean Keys
An Empyrean Key is awarded for opening a Slayer Gate and completing the combat encounter behind it. If all six keys are collected, they can be used to lower a containment field in the Fortress of Doom and retrieve the Unmaykr weapon locked behind it. Empyrean Keys loosely resemble.

Keycards
Keycards are used in a number of levels and come in blue, red and yellow varieties, mirroring the colors used in previous Doom games.
 * In Hell on Earth, a yellow keycard is required to open the passage to the subway.
 * A red key card is found in the Doom Hunter Base.
 * In the opening cutscene for Mars Core, the Doom Slayer encounters a door requiring a red keycard; seeing it on a lanyard around a scientist's neck, he grabs the card and pulls it (and the scientist) towards a nearby reader.
 * The UAC Atlantica Facility includes doors sealed with blue and red keycards.

Cultist key
The cultist key is found in the Cultist Base and is used to open multiple doors in that facility. It resembles a yellow crucifix.

Gore keys
Yellow, red and blue gore keys are found in the Super Gore Nest level. As well as being used to open various Hellgrowth doors, the three keys must be stabbed into receptacles at the top of the gore nest to open a passage leading to its heart. The gore keys resemble fleshy spikes with colored eyes.