The Game Room
Generally all mafia games on SA are to be played in PbP.
To discuss mafia generally, there's the Discussion Thread in Traditional Games.
Play by Post is moderated by AxeManiac, Zoolooman, Louisgod, and others, with Louisgod being the main person who seems to respond to our mafia-related moderation concerns.
Remember: Play by Post is part of SA, and as such, all the Forum Rules, Traditional Games Rules, and Play by Post Rules apply, in addition to the standard mafia rules. Breaking the forum's rules can result in probation or banning. Don't do it!