This last example points to an important difference between Nash equilibria and ESS. Nash equilibria are defined on ''strategy sets'' (a specification of a strategy for each player), while ESS are defined in terms of strategies themselves. The equilibria defined by ESS must always be [[Symmetric equilibrium|symmetric]], and thus have fewer equilibrium points. | This last example points to an important difference between Nash equilibria and ESS. Nash equilibria are defined on ''strategy sets'' (a specification of a strategy for each player), while ESS are defined in terms of strategies themselves. The equilibria defined by ESS must always be [[Symmetric equilibrium|symmetric]], and thus have fewer equilibrium points. |