Codex Entries are challenges featured in the singleplayer and multiplayer of Battlefield 1. Upon completion, Codex entries will display real life historical entries related to World War I. Some challenges include killing enemies with specific weapons or vehicles, play missions a certain way, etc. There are a total of 225 Codex Entries featured in Battlefield 1 with 198 available at launch and 27 added with the release of the Winter Update and the They Shall Not Pass expansion.