2k Games has posted an online FAQ detailing what we should expect from the multiplayer mode in Bioshock 2. Citing limited time available for development and the absence of net-code in the first game, Bioshock 2 will have limited multiplayer support.
Multiplayer in Bioshock 2 will not have support for dedicated servers or LAN matches. Also, players will not be able to kick anyone out of a match. The gamer servers will use a matchmaking system that will aim at matching a player’s skill and online ranking. Speaking of which, Bioshock 2 will have a multiplayer online leaderboard that will record scores from public matches. Players will have an option of a private session with up to nine others players; however scores from this type of session will not be uploaded to the leaderboard. The ranked matches will support of up to five players simultaneously.