Traitor

Mafia

The Traitor knows the identity of the mobsters. He tries to lynch Townies. At the end of any day, the mafia may recruit the Traitor. At that time, he becomes a Mobster. As a Traitor, he is found innocent by the Cop. As a Mobster, he is found guilty. He may NOT communicate with the Mafia while he is still a Traitor.

Alternate rule 1: The Traitor does not know who the Mafia are.

Alternate rule 2: The Mafia does not know who the Traitor is.

I recommend using one or both of the alternate rules.