Rapture was a city that attracted the world's best and the brightest, or at least people who had come under the spell of Andrew Ryan's economic philosophy. There was a vast assortment of people who came to Rapture: from artists to scientists, from engineers to athletes. Rapture's society collapsed into civil war after Atlas' planned attack on the Kashmir Restaurant, and normal citizens were caught up in the struggle for control of the city and its ADAM. In BioShock 2 Multiplayer, these citizens are playable characters.
The color of each playable character's outfit will change during team-based matches, depending on what team they are on. Characters on the player's team will appear blue, while characters on the enemy team will appear red.
Although the multiplayer begins on New Year's Eve, some of the audio diaries from the playable characters reveal that they only began splicing during the civil war. Blanche only began using ADAM after the theaters were forced to close, Naledi began using it when the Bathyspheres were put into lockdown, and Buck started using it when his wife disappeared. Despite this, all characters show severe deformities from the get-go.
The cartoon versions of the playable characters appear in the training videos for the multiplayer Plasmids, except for Mlle Blanche de Glace.
The playable multiplayer characters will say specific lines of dialog when performing various tasks during multiplayer games, like when killing another player. There are several different lines they can say while performing the same task, which are picked at random. However the line the player that controls the character hears, may not be the same as what other players hear.