Mafia
Mafia is a game in which there is the Mafia (Aces; usually three or so), Detective (King), and Nurse/Doctor/Angel (Queen). Other random cards are the towns people.
The cards are dealt out randomly, and everyone looks at their own card, but not at anyones else. Then everyone goes to sleep.
The moderator (or God) wakes up the Mafia member(s), and the Mafia gets to kill somebody. They goes back to sleep
Next, the Detective wakes up. He is allowed to get information about one person that round (i.e., whether or not a player is in the Mafia). The information is usually communicated with some sort of hand signal so nobody but the detective knows anything. The detective then goes back to sleep.
Finally the Nurse/Doctor wakes up and gets to save somebody. If that person saves the person the mafia attempted to kill, that person does not die. A lot of the time however, the nurse/doctor is a selfish... person... and saves themselves so it can be rare to get saved. The nurse/doctor goes back to sleep
Ten everyone wakes up. That night's events are described by the moderator who usually dramatizes them. The person who was killed is then out. If the person was protected by the Doctor, nothing happens.
Each round, following the deaths in the night, the townspeople (everyone) gets to decide on who to lynch mob to death, because they are suspected of being in the Mafia (the Doctor's protection is no longer in effect here). The detective, who may know who is in the Mafia, must not reveal his identity to the Mafia, yet must also try not to by lynched. The Doctor must also try to stay alive, and the Mafia, who are on their own side, must try to get the townspeople to kill themselves.
This repeats until either all the townspeople or Mafia are dead.