Game theory is a study of strategic decision making. More formally, it is "the study of mathematical models of conflict and cooperation between intelligent rational decision-makers." (It is distinct from combinatorial game theory, which has its own tag.)

Game theory is a study of strategic decision making. More formally, it is the study of mathematical models of conflict and cooperation between intelligent rational decision-makers.

N.B. Combinatorial-game-theory () is distinct, being concerned with finite games of skill with no chance and full information.

See Wikipedia entry about Game Theory.