So Long Sucker

So Long Sucker is a board game of negotiation and economic strategy invented in 1950 by the mathematicians Mel Hausner, John Nash, Lloyd Shapley and Martin Shubik, all of whom were associated with game theory research at the time. It is played by four people, each of whom starts the game holding seven chips in their own distinct color. The object of the game is to end up holding all of the chips in play, which a player can only do by persuading opponents to hand over their chips through negotiation, promises and temporary alliances. The game's defining feature, and the source of its name, is that every agreement players make during the game is explicitly non-binding: a player is always free to break a deal the moment it becomes convenient, and in practice winning the game generally requires doing exactly that at some point. A typical game lasts about an hour, and because the win condition is about who is still holding chips rather than who is most liked at the table, the design has been studied as an early, playable illustration of coalition formation and betrayal in game theory. Notably, the game's rules allow a player to win even after every one of their own starting chips has left their hands, since victory is judged by the final state of play rather than by unbroken possession.