Game theory in political science and international relations is primarily concerned with understanding how individuals and groups interact strategically in order to achieve their goals.

Nash equilibrium, Prisoner's dilemma, and Tragedy of the commons are all fundamental concepts in game theory that are used to analyze strategic interactions between individuals and groups.

In a Nash equilibrium, each player's strategy is a best response to the strategies of the other players, meaning that no player can improve their outcome by changing their strategy while the other players keep their strategies unchanged.

The Prisoner's dilemma is a game in which two players cooperate to achieve a mutually beneficial outcome, but are tempted to defect and gain a short-term advantage, even though this leads to a worse outcome for both players in the long run.

The Tragedy of the commons is a situation in which individuals overuse a common resource, such as a pasture or a fishery, leading to its depletion and a worse outcome for all individuals involved.

Game theory can be used to analyze a wide range of political phenomena, including elections, bargaining and negotiation, conflict and cooperation, and many others.

In game theory, voters are typically modeled as rational actors who vote based on their preferences, taking into account the strategies of the other voters and the likely outcomes of the election.

In a bargaining situation, the Nash equilibrium is the outcome that maximizes the joint payoff of the two players, taking into account the strategies of the other players and the likely outcomes of the negotiation.

In a conflict situation, the Nash equilibrium is the outcome that minimizes the losses of both players, taking into account the strategies of the other players and the likely outcomes of the conflict.

Game theory has been used to explain a variety of real-world phenomena, including the Cold War, the Vietnam War, the Israeli-Palestinian conflict, and many others.

One limitation of game theory is that it assumes that players are rational actors, which may not always be the case in real-world situations.

Another limitation of game theory is that it often ignores the role of institutions in shaping strategic interactions between players.

Despite its limitations, game theory remains a valuable tool for analyzing strategic interactions in political science and international relations because it provides a framework for understanding how individuals and groups interact strategically, can be used to predict the outcomes of strategic interactions, and can be used to design policies that promote cooperation and reduce conflict.

One of the most important insights from game theory is that strategic interactions can lead to outcomes that are different from what the players intended, that are Pareto efficient, and that are Nash equilibria.

Game theory has been used to study a wide range of topics in political science and international relations, including voting behavior, bargaining and negotiation, conflict and cooperation, and many others.