Below are the collectibles that can be found during The Blood Swamps campaign in Doom Eternal: The Ancient Gods Part 1. You will need to collect the codex pages to earn the Required Reading trophy and the Support Runes for the Lucky Charm Bracelet trophy. Locating all the secret encounters will reward you with the Hypersonic trophy!
Destroy the the Father’s Life Sphere
Support Rune
Work your way through the Blood Swamps until you reach the giant tentacle. Climb up to the elevated section of ground and head down the stairs. Take a left up another section of stairs then head to the end of the walkway and drop down to the ground below. Melee the breakable wall in the building and head inside until you spot the rune.
Codex: Book of the Seraphs Part V
When you come to a giant wooden sealed door, you’ll need to make your way to the top right section of the wall by using the jump bar near the spinning fire chains.
Jump across the gap to the top of the wall across the way then drop down into the water. Pick up the hazmat suit and dive into the water. Turn around to find a little hole containing the codex.
Extra Life
After using a green skull to open the sealed doors as part of the story, turn around and drop down to the ground below. The extra life will be located behind a breakable door to the right.
Extra Life
From the life sphere, follow the path to the western trial. When you reach the ravine, look down to find a cave behind a small waterfall draining into the ravine underneath the path your suppose to take. Jump to the cave to find the extra life.
Extra Life
This extra life can be found on the way to the western trial in the water. To release the water, you will need to break the wall underneath the skull.
Codex: Book of the Seraphs Part VI
As you progress towards the western trial, you’ll come to a foggy area with a lot of enemies in the water near the remains of a giant skeleton. By the base of its neck, there will be deep water you can dive into. Search for the underwater cave then follow it to the end. When you emerge from the other side, follow the path to reach a gap.
Secret Encounter
Facing the door to the western trial, head to the back left side of the courtyard and climb up a small set of stairs. Take a right then drop down below to a platform across the gap. Follow the path forward coming to a ledge. Smash through the wall ahead and melee the giant metal cube to unseal the secret encounter below.
Codex: Book of the Seraphs Part VIII
Just before reaching the top of the tower for the western trial, you’ll reach an open area with 2 spinning yellow spin bars. Use the 2 bars to reach a climb wall to the right of the far bar. Climb to the top of the wall then jump across the gap to reach the codex.
Codex: Book of the Seraphs Part VII
As you head towards the eastern trial, you’ll come across a spirit wolf leading you to an alter site where you’ll have to fight off a wave of enemies. This codex can be found on a ledge overlooking the ritual site of the second wolf.
Secret Encounter
This encounter can be found behind a gate in the third area that the spirit wolf leads you to. To reach it, head to the gate leading to the tower of the trial then press forward west of the gate. Follow the path around to a marsh area. You’ll need to jump to the second rock column sticking out of the marsh with an exploding egg.
From there, jump straight ahead east to use a spin bar to reach a climb wall. Follow the path to reach a giant metal cube that you will need to use to unseal the way to the encounter.