Codex



The codex is the protagonist's mobile database of information on monsters, weapons, items, upgrades, and plot elements in the Doom. It automatically updates with new information as monsters are killed and items are collected, and can be referenced at the player's convenience, taking the place of Doom 3's PDAs and functioning in a manner similar to the scan log in the  series. Some data log messages are acquired from datapads.

Gallery
Some example codex entries are pictured here.