Game Theory studies the behavior of decision makers ("players") whose decisions affect each other. As in one-person decision theory, the analysis is from a rational viewpoint. Game theory has important applications and connections to many disciplines, mainly economics, and also evolutionary biology, computer science, the foundations of mathematics, statistics, finance, psychology, political science, law, and philosophy.

The game theory group in the Department of Mathematics of the Hebrew University of Jerusalem has been a worldwide leader in the area since the 1960s, shaping the conceptual and mathematical foundations of the field.

Faculty members in Game Theory & Mathematical Economics:

- Robert J. Aumann (emeritus): Game theory, Mathematical economics.
- Sergiu Hart (emeritus): Game theory, Mathematical economics, Rationality.
- Abraham Neyman (emeritus): Game theory, Mathematical economics.
- Bezalel Peleg (emeritus): Game theory, Mathematical economics.