Ankur Moitra teaches this lecture from MIT's 18.200, Principles of Discrete Applied Mathematics, on the game theory of zero-sum games. He defines the payoff matrix that represents a two-player zero-sum game and works through examples, starting with matching pennies before moving to a more complicated game with a larger strategy space. The lecture builds toward Nash equilibrium, explaining what it means for neither player to have an incentive to deviate from their strategy given the other's choice. Moitra develops the ideas on the board with worked examples rather than slides, connecting the abstract matrix formulation to concrete strategic reasoning. At 74 minutes, it functions as a self-contained introduction to a core topic in combinatorial game theory, assuming only the linear algebra and probability background typical of an undergraduate discrete math course.