Charles Tilly has introduced to historical and sociological discourse the concept of the repertoire of collective action. The concept is rooted in the observation that “any given population tends to have a fairly limited and well-established set of means for action on shared interests. . . .” (Tilly 1977: 39) The repertoire of collective action, like its theatrical counterpart, implies a group of actors who choose among a restricted number of performances with which they are familiar. Their options are circumscribed both by prior experience and by the material, organizational, and conceptual resources they find readily at hand (Tilly and Tilly 1981: 19). Tilly also likens the repertoire of collective action to a game that involves a set of basic rules around which a considerable degree of extemporization is not only permitted but required. The result is a “paradoxical combination of ritual and flexibility” (Tilly 1977: 22; Tilly 1986b: 33, 37) in which neither element must be allowed to displace the other, lest the performance lose either its creative edge or its ready communicability.