Since the first chapter of Doom: The Dark Ages, secret keys have been a part of the game, providing access to hidden locations and valuable loot. With eight chapters and one secret key per chapter, collecting them all is crucial to maximising your resources and discovering everything the game has to offer.
But finding these keys can be a distraction from demon slaying, particularly when some are hidden behind puzzles or offshoot paths. To assist with the streamlining of your search, we’ve put together this guide to all the established Secret Key locations for Doom: The Dark Ages so that you can keep your focus on the battle.
Secret Key Locations by Chapter
Chapter 1: Village of Khalim
The initial Secret Key is in the beginning chapter and is not too hard to locate. While you go through the main quest line, you will sooner or later end up on a mountain trail.
Follow the path along the turn and up the slope, and you will have the key there awaiting you by the indicated place on the map. This key is hard to miss if you’re sticking to the story objectives, making it a great introduction to the mechanic.
Chapter 6: Siege Part 1
The Secret Key in Chapter 6 is found during the first part of the Siege sequence. You can find it in an open area, and the best part about this ordeal is that you aren’t required to solve any puzzle or explore beyond reaching the spot marked on your map.
But this doesn’t discern the fact that you won’t have to look hard for the key, as you can easily rush past it and miss out on the item.
Chapter 7: Siege Part 2
Chapter 7’s key is harder to find and entails a tiny environmental puzzle. While making your way up to the second floor as part of the main questline, be sure to look for a destructible wall beside an open balcony. Break through it to find a secret passage.
Make your way along this hidden path to where there is a jump booster that will propel you to a ledge over the gap. There, you will discover the Secret Key. This key provides entry to a hidden reservoir of rubies, making the extra effort worthwhile.
Chapter 9: Ancestral Forge
In Chapter 9, the Secret Key is back to being easily accessible. Like in previous chapters, just go to the marked location on your map. The key is sitting in plain view on the floor, with no obstacles or puzzles hindering access.
It is one of the quickest keys to grab and is ideal for those wanting to keep things moving in the campaign.
Chapter 10: The Forsaken Plains
Secret Key in Chapter 10 is one of the first things you’ll spot in this mission, but it’s not immediately accessible. Near the beginning of the level, you’ll see the key locked behind a gated doorway.
Use the Shield Recall ability to scale the building on the left side of the area. After you’re on the rooftop, look for a big hole in the ground close by. Fall through this gap to come inside the locked room, where you’ll find access to the Secret Key. The Shield Recall ability is not only a combat action, it’s a helpful navigation tool, particularly on missions featuring vertical puzzles such as this one.
Chapter 12: Sentinel Command
Chapter 12’s Secret, held in the Sentinel Command, involves some environmental puzzling and foe dispatching.Make your way around the large command room via the thin paths constructed into the walls. Search for a ventilation shaft that you can climb, found beyond the Life Sigil.
After crawling, you’ll find yourself in a room with the Secret Key—but there’s a guardian in the way. Clear all the enemies in the room. With the area cleared, the key is now available. This section rewards quick movement and effective crowd control. Use weapons or upgrades that handle groups well.
Chapter 17: Temple of Lomarith
Proceed to the final area of the chapter, where your objective is to unlock and enter the temple. Nearby, you’ll notice a massive ship docked at one of the map’s corners. Climb aboard the ship and defeat the enemies stationed there.
Once the enemies are defeated, a door at the back of the ship will automatically open, revealing the Secret Key. This is a simple combat puzzle. Carry heavy weapons to handle the mini-arena-type combat on the ship.
Chapter 22: Reckoning
Follow the main campaign progression until you reach the elevator leading to Ahzak’s ship’s boarding deck. Once you reach the top and the elevator opens, turn back instead of proceeding.
The Secret Key is just at the back of the gate through which you had entered when ascending. Getting this final key tends to open up extra endgame secrets, so you don’t want to miss out on it during the excitement of the last mission.
