Altaïr Ibn-La'Ahad's Codex

The Codex documents are documents left behind by Altair, containing cryptic messages. In Assassin's Creed II, Ezio takes the Codex papers to Leonardo da Vinci, who interprets them, and creates weapons using guidelines encrypted on the Codexes. In order to complete Assassin's Creed II, the player must collect all 30 Codexes. If the player doesn't have all of the Codexes once they are ready for Memory Block 14, all of the Codexes will appear on that player's map.