How Do You Find the ESS Game Theory?


Martha Robinson

Do you want to learn about ESS Game Theory? Evolutionary stable strategy (ESS) is a concept in game theory that refers to a strategy that, once adopted, cannot be displaced by any other competing strategy.

In simpler terms, an ESS is a strategy that is so successful that it becomes the dominant strategy in a given population. But how do we find such strategies? Let’s explore some ways to do so.

Define the Game

The first step in finding an ESS is to define the game being played. This involves understanding the rules of the game and identifying the players involved. Once you have a clear understanding of the game being played, you can start analyzing different strategies and their outcomes.

Assess Possible Strategies

To find an ESS, it’s important to assess all possible strategies available to players. This includes considering both pure strategies (where players choose one option) and mixed strategies (where players randomize their choices).

Pure Strategies

Let’s consider a simple example of rock-paper-scissors. The pure strategies in this game are rock, paper, and scissors.

Each strategy has its own strengths and weaknesses against other strategies. For example, rock beats scissors but loses to paper.

Mixed Strategies

In games with more complex outcomes or multiple rounds of play, mixed strategies become more important. Mixed strategies involve choosing a probability distribution over different pure strategies. For example, in poker, a player may choose to bluff with a certain probability or play conservatively with another probability.

Identify Payoffs

The next step in finding an ESS is to identify payoffs for each player based on their chosen strategy. Payoffs represent the benefits or gains that each player receives from playing a particular strategy.

Apply Evolutionary Dynamics

Once you have identified possible strategies and payoffs, you can apply evolutionary dynamics to determine which strategies are most likely to become dominant. Evolutionary dynamics involve simulating the game being played repeatedly with different players and tracking the success of different strategies over time.


In summary, finding an ESS involves defining the game being played, assessing possible strategies (both pure and mixed), identifying payoffs, and applying evolutionary dynamics. By following these steps, you can identify the most successful strategy or combination of strategies that will become the ESS in a given population.