White Flag (mechanic)
The White Flag mechanic is a variation where if there is only one member of the Mafia alive, they surrender. Thus, the last two scum alive cannot bus each other, but must protect each other from being eliminated.
Theoretically, White Flag makes it considerably more likely for Town to win, as they only have to get (usually) two out of three scum to die. In practice, the White Flag Gambit has kept scum win rates high as Towns have tried to hunt for the last two players by association.
White Flag is also the name of an Open Setup that uses this mechanic.
The White Flag mechanic was first suggested by mith (paired with a similar condition for Town being reduced to 1/3 of their number, which was later used in Black Flag Nightless), and independently suggested by zoraster for use in Mini 1030.