▷Doom Eternal: Ancient Gods - All Codices, Rune Keys & Secret Locations

And there are more collectibles to grab between the Hyperactive Demon Battles. We've listed them all below for you to browse at your own pace. Collectibles are easier to find this time around - if you check the map often, you'll spot small areas you haven't explored. There is always something in these little corners. If you need confirmation, just check the locations (and screenshots) below.

UAC Atlantica Facility Collectibles Guide | How to unlock support runes and which to choose first

Support rune: Defeat the Marauder in a small arena in front of the swamp and the giant tentacle. Go to the ledge with the fire traps, and at the end go down. A cracked wall leads to a secret path.

Codex # 1: After skipping the space above the Marauder Arena, jump into the swamp below (past where you need to double jump and double dash) and land in the water where a Cyber-Mancubus appears. Right under the water there is a hidden alcove with a codex.

Loyalty card: Get out of the water after Cyber-Mancubus to find the level map.

1-Up: Go up the map in the arena with the Baron of Hell. Defeat him and smash the cracked wall in the left corner.

1-Up: First taking the left path, erase the first meeting and swing on the post. You will have to jump on a raised ledge - there is a lower ledge that you can jump on hidden behind a thin waterfall containing a 1-Up.

1-Up: In the test arena on the left where the Doom Hunter appears, dive into the water pool and break the cracked wall below.

Secret meeting # 1: The secret encounter on the left side of the level is found after exiting the Misty Swamp arena with the Spirit. You will find him in a cage, in an upper chamber after several pole vaults.

To open the cage, continue until you reach the main judgment chamber after meeting the tyrant. After that, the demon wall will drop down, giving you access to an optional path in front of the main door. Punch the rim box.

Codex # 1: On the left side you will reach a Tyrant arena with invisible Whiplash enemies. On the right edge there is a water pool that you can dive into. There is a codex and BFG ammo at the end.

Munitions BFG: After reaching the top of the obstacle course on the left trial, there is a cracked door that you can break.

Codex # 2: Beyond the obstacle course, you will reach revolving poles. Jump to the ledge where the elemental pain appears, then jump to the distant tower - from this small tower you can reach the ledge with this codex.

Codex # 3: On the right path you will enter an area where you will have to stay with the Spirit Dog to protect yourself. Once you've completed this section and unlocked the Trial Chamber, head to the swamp. There is a pillar where you can jump on a distant pole where you can connect to a climbing wall.

Secret meeting # 2: From the codex, drop into the deep hole of the upper bridge. It leads to an optional path that will take you down and behind the Secret Encounter Chamber.