DOOM Eternal

There are a total of 10 new Codex to be found;
Level 1 - The World Spear - 2 Codex
Level 2 - Reclaimed Earth - 4 Codex
Level 3 - Immora - 4 Codex

The Codex are located on your path as you progress through a level, so you shouldn't really miss them. They can either be located as a '?' on the map, or if you found the AutoMap in the level (again, really not hard to locate as it's on your path as you progress), the Codex symbol will appear on the map.

Once you've found the final Codex the achievement will unlock. You can replay chapters if you do happen to miss a few.

Hope this helps! I know some people prefer video guides, but honestly, they are not hard to locate at all.

EDIT:

Video Guides by 360GamesTV, full credit goes to them. Videos include all extra lives and codex locations.

World Spear - Reclaimed Earth - Immora -

Hi All

There are 16 collectables for the hammer upgrades and codex to find. The hammer requires you to complete two gore nests in each level. There are 10 codex pages all together, our video covers all their locations, timestamps below:


TIMESTAMPS:

- 0:00​ - Intro
- 0:33​ - The Steppes - Codex
- 0:56​ - The Steppes - Hammer Upgrade
- 1:44​ - The Steppes - Hammer Upgrade
- 2:32​ - The Steppes - Codex
- 2:51​ - Reclaimed Earth - Codex
- 3:16​ - Reclaimed Earth - Hammer Upgrade
- 4:07​ - Reclaimed Earth - Hammer Upgrade
- 4:56​ - Reclaimed Earth - Codex
- 5:23​ - Reclaimed Earth - Codex
- 5:54​ - Reclaimed Earth - Codex
- 6:18​ - Immora Codex
- 6:44​ - Immora - Hammer Upgrade
- 7:48​ - Immora - Hammer Upgrade
- 8:41​ - Immora - Codex
- 8:59​ - Immora -Codex
- 9:32​ - Immora - Codex