http://blankmediagames.com/

"Town of Salem is a browser-based game that challenges players on their ability to convincingly lie as well as detect when other players are lying. The game ranges from 7 to 15 players. These players are randomly divided into alignments - Town, Mafia, Serial Killers, Arsonists and Neutrals. If you are a Town member (the good guys) you must track down the Mafia and other villains before they kill you. The catch? You don't know who is a Town member and who is a villain. If you are an evil role, such as a Serial Killer, you secretly murder town members in the veil of night and try to avoid getting caught."

This game has a growing community that I hope many of you will become a part of. This is possibly the best Alpha game I have ever played :O

Town of Salem is quite similar to a card game known as "Mafia" that you may have played previously. It is basically an online version of that.