Audio Diaries are the main narrative device of the BioShock series. They were recorded by the citizens of Rapture, either as notes for themselves or as messages for other residents. The Log Recorder is a special Audio Diary in the Player's Apartment in BioShock 2 Multiplayer where the player can access the playable characters' Audio Diaries that they have unlocked. The Log Recorder starts out with one Audio Diary from the ten total playable characters. The rest are unlocked through achievement of higher Ranks.