# How Do You Find Dominant Strategy in Game Theory?

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Diego Sanchez

Game theory is a fascinating branch of mathematics that deals with analyzing the behavior of individuals and organizations in strategic situations. One of the key concepts in game theory is the dominant strategy, which refers to the best course of action for a player regardless of what their opponents do.

Finding the dominant strategy in a game can be a challenging task, but it is essential for making informed decisions and maximizing your chances of success. In this tutorial, we will explore how to find dominant strategies in game theory.

## What is Game Theory?

Game theory is a mathematical framework that studies decision-making in competitive situations where the outcome depends on the choices made by multiple players. It was developed by mathematicians such as John von Neumann and Oskar Morgenstern in the 1940s and has since become an important tool in fields such as economics, political science, and psychology.

In game theory, players are assumed to be rational and self-interested, meaning they will always act to maximize their own utility or payoff. A game typically consists of three elements: players, strategies, and payoffs.

A player is an individual or organization that makes decisions in the game. A strategy is a set of actions that a player can take, while a payoff represents the outcome or reward associated with each possible combination of strategies chosen by all players.

## What is Dominant Strategy?

In game theory, a dominant strategy is one that provides the best outcome for a player regardless of what their opponents do. In other words, it is always preferable to choose a dominant strategy because it guarantees the highest possible payoff no matter what happens.

For example, consider a simple game where two players can choose between two strategies: A or B. The payoffs for each combination are shown in the following table:

• If both players choose A: Player 1 gets 1 and Player 2 gets 2
• If both players choose B: Player 1 gets 3 and Player 2 gets 1
• If one player chooses A and the other chooses B: Player 1 gets 0 and Player 2 gets 0

In this game, the dominant strategy for both players is to choose strategy B. This is because no matter what the other player does, choosing B always yields a higher payoff than choosing A.

## How to Find Dominant Strategy?

Finding dominant strategies can be a complex task, especially in games with many players and strategies. However, there are some general techniques that can help simplify the process.

One approach is to use a process called iterative elimination of dominated strategies. This involves systematically eliminating any strategies that are strictly dominated, meaning they always yield a lower payoff than another strategy regardless of what the other players do.

For example, consider a game where two players can choose between three strategies: X, Y, or Z. The payoffs for each combination are shown in the following table:

• If both players choose X: Player 1 gets 3 and Player 2 gets -1
• If both players choose Y: Player 1 gets -1 and Player 2 gets -3
• If both players choose Z: Player 1 gets -2 and Player 2 gets -2

To find the dominant strategies in this game, we start by comparing each pair of strategies for each player. We can see that strategy X dominates strategy Z for Player 1 because it yields a higher payoff no matter what the other player does. Similarly, strategy Y dominates strategy Z for Player 2.

After eliminating these dominated strategies, we are left with a simplified game where both players have only two strategies to choose from: X or Y. We can then compare these strategies to find the dominant strategy for each player.

In this case, we can see that there is no dominant strategy for either player because the payoffs are equal for both X and Y. Therefore, the players must make a strategic choice based on other factors such as their beliefs about what the other player will do.

## Conclusion

Finding dominant strategies is an important tool in game theory that can help you make informed decisions and maximize your chances of success in strategic situations. By using techniques such as iterative elimination of dominated strategies, you can simplify complex games and identify the best course of action for each player.

Remember that game theory assumes rational and self-interested players, so it is essential to consider factors such as trust, reputation, and communication when applying these concepts to real-world situations. With practice and experience, you can become a master of game theory and gain a deeper understanding of human behavior in competitive environments.