Mafia
This is what the game gets its name from: obviously, it is one of the most important roles and is in almost every game. The members of the Mafia (also known as Villains) usually know each other and can talk to each other at
night. Each
night, they choose a victim from the rest of the players. Sometimes this is a collective decision, while other times, the kill is dictated by a specific player. When
day breaks, the victim is dead, provided there is no interference. The goal for the Mafia is to survive while killing everyone else in town.
A very common variation on this role is to have two (or more) Mafia families, sometimes called factions. Each family operates separately, and are not on the same side; a family only wins when everyone else, including the other family, is dead.