game theory 
(also games theory)
noun [mass noun]
The branch of mathematics concerned with the analysis of strategies for dealing with competitive situations where the outcome of a participant’s choice of action depends critically on the actions of other participants. Game theory has been applied to contexts in war, business, and biology. Compare with decision theory.However, I concentrate on how it might be rational for you alone to choose: game theory concentrates how we might each choose in a jointly sustainable way....
- His early works range over number theory, statistics, combinatorics, game theory, as well as his principal interest of commutative algebra.
- He was always full of mathematical ideas, not only on game theory, but in geometry and topology as well.