A multiplayer game is a game having several players, who may be independent opponents or teams. Games with many independent players are difficult to analyze formally using game theory as the players may form and switch coalitions. The term "game" in this context may mean either a true game played for entertainment, or a competitive activity describable in principle by mathematical game theory.
John Nash proved that games with several players have a stable solution provided that coalitions between players are disallowed. Nash won the Nobel prize for economics for this important result which extended von Neumann's theory of zero-sum games. Nash's stable solution is known as the Nash equilibrium.
If cooperation between players is allowed, then the game becomes more complex; many concepts have been developed to analyze such games. While these have had some partial success in the fields of economics, politics and conflict, no good general theory has yet been developed.
In quantum game theory, it has been found that the introduction of quantum information into multiplayer games allows a new type of equilibrium strategy not found in traditional games. The entanglement of players's choices can have the effect of a contract by preventing players from profiting from what is known as betrayal.
Examples of multiplayer games for entertainment include:
- Party games – a social game played with a number of people, little equipment, and simple rules (e.g. Charades)
- Card games – played with a deck of cards. (e.g. Contract Bridge)
- Board games – played on a gameboard with set rules (e.g. Monopoly)
- Multiplayer online games – played over the Internet
- Massively multiplayer online role-playing games – a notable subset of online games
- Multiplayer video games – played on a game system or network
Examples of serious multiplayer games are:
- Simulation – where something (e.g. a company or a micronation) is simulated for education or study
- Oxford English Dictionary. Oxford University Press. 2008.
Designed for or involving more than two (esp. many) players or participants
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- Laszlo Mero; Anna C. Gosi-Greguss; David Kramer (1998). Moral calculations: game theory, logic, and human frailty. New York: Copernicus. ISBN 0-387-98419-4.
- Simon C. Benjamin & Patrick M. Hayden (13 August 2001). "Multiplayer quantum games". Physical Review A. 64 (3): 030301. doi:10.1103/PhysRevA.64.030301.
- R. Wayne Schmittberger (1992). New Rules for Classic Games. New York: Wiley. ISBN 0-471-53621-0.