Doom: The Dark Ages: Slayer Key Locations & Interactive Tracking Guide

The classic Doom keycard system returns in Doom: The Dark Ages in the form of Slayer Keys — coloured items that unlock the Night Sentinel fortress gates and the fleshy doors of Hell.

There are 13 Slayer Keys across 11 chapters, in four distinct physical forms: stone pin-tumbler keys (Blue and Yellow, found in Sentinel territories), the spiky Purple Secret Key (engraved with a purple rune, always optional), facility-style Keycards (Blue and Yellow, found in Sentinel installations), and demonic Skulls (late-game chapters).

All 13 are plotted with precise locations across the chapter maps on MapMaster's interactive Doom Dark Ages maps.

How Slayer Keys Work

Once a Slayer Key is in inventory, locked doors of the matching colour open automatically on approach — no button press is required. Collected keys are displayed at the top of the HUD and persist until the chapter ends.

Keys do not carry over between chapters — any key not used before the chapter concludes is lost. Use the corresponding gate before progressing past the chapter's Point of No Return.

Keys not yet collected appear as coloured holograms in the world — a floating, glowing outline visible before pickup that makes uncollected keys easier to spot mid-combat.

Once a key is within the Slayer's line of sight (even through a wall), it also registers as a Key Icon on the AutoMap. Corresponding gates appear as Red Gate Icons before the key is found; they turn Green once the key is in inventory.

The Purple Secret Key: Most Commonly Missed

The Purple Secret Key is the key type that most consistently sends players back to Chapter Replay. Unlike Blue and Yellow Keys — some of which are story-mandatory — Purple Keys are always optional, always hidden off the main path, and always gate the richest Secret Areas in their chapters, including Collectible Toys, Rubies, Wraithstones, and Weapon Skins.

Purple Keys appear in Chapter 1: Village of Khalim, Chapter 6: Siege – Part 1, Chapter 7: Siege – Part 2, Chapter 9: Ancestral Forge, Chapter 10: The Forsaken Plains, Chapter 12: Sentinel Command Station, Chapter 17: Temple of Lomarith, and Chapter 22: Reckoning.

Slayer Keys by Chapter

• Chapter 1 — Blue Key (church altar), Purple Key (cliff top after third Demonic Portal)
• Chapter 7: Siege – Part 2 — Purple Key (Jump Pad balcony)
• Chapter 8: Abyssal Forest — Yellow Key (behind gate at end of western tunnel, opens the Yellow Forest Gate)
• Chapter 9: Ancestral Forge — Purple Key (behind Weak Wall)
• Chapter 10: The Forsaken Plains — Purple Key (caged area, drop through hole on top floor)
• Chapter 12: Sentinel Command Station — Yellow Key (story-mandatory, on a corpse next to an upper-level console), Purple Key (Hidden Room, defeat the Encounter to lower the barrier)
• Chapter 17: Temple of Lomarith — Purple Key (back of the shipwreck's upper-level gate)
• Chapter 20: Resurrection — Yellow Key (wooden platform edge after clearing Encounter), Blue Key (ground after wall climb)
• Chapter 22: Reckoning — Blue Skull Key (pedestal after wall climb), Purple Key (ground after elevator)

The Sentinel Trail Tip

If a locked gate is visible but the key cannot be found, look for Sentinel Trail Markings — white paint applied to rocks and walls by the game's developers to indicate optional platforming paths.

These markings reliably lead toward Slayer Key locations that sit off the standard combat route, most commonly the Purple Secret Keys hidden on elevated terrain or behind breakable surfaces.