The Warhammer 40,000 Codex books contain the complete rules for playing various armies in Warhammer 40,000. They also contain in-depth painting guides, army lists, and much more. Please note as of August 2020, all codex books have their own individual entry on BGG. You may use the customizing version option if you wish to have it show up in your collection and not worry about moving logged plays. Creating custom versions in your collection and selecting custom representative images