Rune

Runes are demonic sigils in Doom (2016) and  Doom Eternal which upgrade the Doom marine's intrinsic abilities. There are twelve distinct runes, each of which must be earned by finding its rune stone, a green glowing monolith bearing the runic mark, and defeating the ensuing rune trial, a battle which occurs in a small enclosed space disconnected from other game play areas. The runes are passive permanent upgrades, but only a certain number can be equipped at a given time, based on the Praetor suit's current capabilities. A maximum of three runes can be equipped when the protagonist is at full power.

Multiplayer
Runes are introduced in Update 6.66, replacing hack modules. Runes now last throughout the user's life instead of being single-use items, and they are unlocked via player progression. Their effects are greatly simplified as well, as they are no longer ranked by tiers and some effects from hack modules have been combined together. Up to three loadout slots are provided to the player once unlocked, which are used to select a single rune for each match.

Runes are not available in Clan Arena and Infernal Run.

Doom Eternal
You can now choose the rune that is unlocked when you find a rune's location, allowing these to be earned in any order.

Support Runes
Added in Update 3, Support Runes take up a specialized slot and can be awarded either after clearing a Slayer Gate or finding their hidden locations.

Trivia
The single-player runes of Doom (2016) are loosely based on s and diabolical seals used in, as derived from various medieval s and the well-known 17th century occult book, the . None of the runes exactly match actual known sigils, however.