Drafterman recently described mafia as a game of social deduction with an informed minority and an uninformed majority. Survivor involves just as much deduction, with one twist: there are no factions, at least not ones that can ultimately share the win. There is one winner. One Survivor. Every round there is a challenge that will make one person (or multiple people depending if we can get enough players to have tribes) safe, everyone else is eligible to be voted out at tribal council. During the game, players will PM one another and form alliances to keep themselves safe and see their enemies go home. When two players are left, the last set of people voted out, the jury, will vote for who they believed outwitted, outplayed. and outlasted the best to become the Sole Survivor!
I'm aiming for 12 people, but more or less can work.