In Chapter 9, we will Extensive form gamesintroduce the model of extensive form games that will allow us to study games where players can play their actions sequentially or repeatedly. Section 9.1 will present the basic structures of the model, followed by some examples. Section 9.2 will discuss how an extensive form game can be represented as a strategic form game and Sect. 9.3 will present two alternative representations for the strategies of players in an extensive form game and a result that shows when these two representations, known as mixed and behavior strategies, are equivalent.