Game theory is the field of applied mathematics that models interactions between multiple agents as "games" of strategy between "players". It is a scientific method of describing, predicting, and evaluating choices (or "actions"), often with the view of maximising utility outcomes (or "payoffs") for one or more players.

Game theory has applications in the natural, formal and social sciences, including biology, computer science, economics, law, logic, political science, systems science, and philosophy. Subfields of game theory include algorithmic game theory, behavioral game theory, combinatorial game theory, evolutionary game theory, and quantum game theory.

In 1994, the Nobel Prize in economics was awarded to the mathematician John Nash, the philosopher John Harsanyi, and the economist Reinhard Selten for their pioneering work in game theory. Since then, game theorists who were warded the Nobel include Thomas Schelling and Robert Aumann (2005), Leonid Hurwicz, Eric Maskin, and Roger Myerson (2007), Alvin E. Roth and Lloyd S. Shapley (2012), Jean Tirole (2014), and Paul Milgrom and Robert B. Wilson (2020).