As I mentioned before you can be a character that has a role but you could get a role that isn't who your character. For instance I picked Luigi for my character but I could get any role.I could be a Mafia member,Bomb-omb,one of the hammer bros, a townie role,or just a normal townie.
Oh so you have played this before.If I recall correctly Vudu started with the real life Mafia game.