Variants of Mafia Rules
Blind Mafia
A group in Hungary plays that the mafia must choose who to kill with their eyes closed-- as best we can tell, the moderator calls out the names of each player in turn, and each mafia member raises his hand when he hears the name of the civilian he wishes to kill. A majority of the mafia must choose the same civilian. If no majority is attained, the moderator, after coming to the end of the list of names, announces that noone was killed during the night. The mafia know who each other are, because they are allowed to see each other during the first night. However, because nighttime communication between them is forbidden, they must somehow communicate by secret signals during the day.
We use a different gameplay variant which we also call "Blind Mafia", as explained briefly on the PDF rules sheet:
Sometimes it is a really bad idea to have mafia members know each other, such as in the case of Multiple Lives. In that case, if a mafia dies and becomes a Civilian in his second life, he can just point at all the remaining mafia!
Mafia members never gets to know each other. Instead, the moderator must wake every player in turn, knowing which character they are, or alternatively call the Mafia characters by role. In our deck, that means to call the Godfather (clubs K), the Godmother (clubs Q), etc. When your card is named, you have 3 choices: kill someone (point at a player), "no kill" (there will be no mafia-related death that night) or "pass" to a lower ranking mafia member. The highest ranking mafia player alive decides for the group. Thus if the Godfather is alive and decides "no kill", then all other mafia members can try anything they want, it will have no effect.
If one's kill does not go through (someone else dies), it is a good way to know a higher ranking mafia is alive. Similarly for lower-ranking mafia if one "passes" and someone dies.
Mafia is not immune to mafia death. If the godfather passes to the queen and the queen points at the godfather, too bad!
Because of this vulnerability and the fact that mafia is not a voting block during daytime, we put more "bad guys" in the deck if mafia is blind.Source:
http://www.princeton.edu/~mafia/vgp4.htm