Research on the tactical repertoires of social movements argues that new tactics emerge as a reaction to defeat or in response to the broad historical, political, and cultural changes associated with protest cycles. This paper complements this work by examining the characteristics of protest events that are associated with tactical innovation. Using novel network analytic measures and data on over 23,000 protest events that took place in the United States between 1960 and 1995, results show that tactical innovation occurs at events that span dissimilar movements (spillover) and at events staged by more isolated or peripheral social movements (isolation). Specifically, protest events that span different movements tend to utilize novel recombinations of tactics while events with more peripheral movement claims are more likely to deploy new protest tactics. We bring together sociological work on social movement dynamics, innovation, and field theoretic approaches to develop a new theorization of the relationship between the tools and content of activism.