Two gunfighters slam out of a decrepit saloon and stalk toward their posts at either end of the street. Facing each other, they prepare to draw their six-shooters. Abruptly, a third gunfighter steps out. Game theory typically deals with the consequences of players' actions, given the rules of the game.
Researchers seek to determine the optimal outcome in a particular situation.
In a truel, each of the participants fires bullets at the others to try to eliminate them and survive. Game theorists are interested in the nature and timing of each player's actions against his or her opponents. Truels can arise in a variety of real-life situations, ranging from fierce rivalry among animals living in close proximity to competition among the major television networks. In the December 1997 Mathematics Magazine , D. Marc Kilgour of Wilfrid Laurier University in Waterloo, Ontario, and Steven J. Brams of New York University provide a detailed look at truels, highlighting how small changes in the rules can lead to startlingly different, sometimes counterintuitive outcomes. Here's a typical decision problem involving a truel.