 Whereas Lewis allowed the “audience” to consist of more than one person, it is more common to consider sender-receiver games played between two people, so that there is only a single receiver (or, in Lewisian terms, a single member of the  audience).[11]  For simplicity, in the following we will consider a two-player, sender-receiver game with two states of the world \(\{S_1, S_2\}\), two signals \(\{\sigma_1, \sigma_2\}\), and two responses \(\{r_1, r_2\}\). (We shall see later why larger sender-receiver games are increasingly difficult to analyse.)