ABSTRACT
When game theorists refer to a game’s ‘solution’, or a ‘solution concept’, they have in mind how rational people might play the game. A ‘rational solution’ corresponds to a set of strategies (one for each player) that the players of the game have no (rational) reason to regret choosing. It is in this sense that a game’s ‘solution’ is often used interchangeably with the term ‘equilibrium’. The most important solution concept in game theory is the Nash equilibrium. We shall see later how Nash’s most influential ‘solution’ is based on the idea that, in equilibrium, players’ strategies must be best replies to one another.
