 Following  Lewis’s (1969)  introduction of coordination games into the philosophical literature, the philosopher Margaret  Gilbert (1989)  argued, as against Lewis, that game theory is the wrong kind of analytical technology for thinking about human conventions because, among other problems, it is too ‘individualistic’, whereas conventions are essentially social phenomena. More directly, her claim was that conventions are not merely the products of decisions of many individual people, as might be suggested by a theorist who modeled a convention as an equilibrium of an n-person game in which each player was a single person. Similar concerns about allegedly individualistic foundations of game theory have been echoed by another philosopher, Martin  Hollis (1998)  and economists Robert Sugden  (1993,  2000,  2003)  and Michael  Bacharach (2006).  In particular, it motivated Bacharach to propose a theory of team reasoning, which was completed by Sugden, along with Nathalie Gold, after Bacharach’s death. This theory constitutes a key part of the background context for appreciating the value of a major recent extension to game theory, Wynn  Stirling’s (2012)  theory of conditional games. 