It's a the most popular type of forum game you'll find here.
The basic layout is that there are a number of players (normally 6-8) that post that they will play on a sign-up thread, as well as a host player. The host player then creates characters for the players to become (normally 2 characters per player) and sends them to the player via PM. The player then creates new profiles for these characters, where the usernames are the actual names of the characters.
Now for every game, naturally there are mafia. The mafia can be any group, witches, werewolves, assassins, or just plain mafia thugs. For a game of 12 characters there are normally 4 mafia characters, and for a game of 16 characters there are normally 6 mafia characters. These mafia characters all agree on one person to kill during the night phase via PM, and sometimes they have special powers as well. The goal of the mafia players is to kill enough innocents so that the mafia is in the majority.
There are also innocents in every game. These innocents may or may not have powers depending on the host's discretion, and for a game of 12 characters there are normally 8 innocents, and for a game of 16 characters there are normally 10 characters. The innocents need a majority vote every day phase in the thread to lynch one character in the hopes that player is mafia. The goal of the innocents is to kill all mafia players, while at the same time remaining in the majority.
Due to people logging on at different times, each day phase can last for several days, and the night phase normally a little shorter than the day phase. Because of this, each mafia game can actually last several weeks before it's over.
