This study examines the first two years of a tactical innovation that emerged in 2012 in Egypt, which involved activist groups organizing patrol-type "intervention teams" to combat sexual violence against women in public spaces. Findings reveal that the new tactic took different forms in the two places in which it was deployed, even though the same actors employed it. I argue that the place in which a new tactic emerges shapes the form it takes. When coming up with a new collective action tactic, activists elaborate visions about how to carry out their actions based on their collective identities and taste in tactics. But as they start experimenting with the new tactic on the ground, they learn about the places' material affordances, symbolic valence, and power relations, as well as the constraints and opportunities that they represent. The material properties of places shape activists' possibilities of movement, patterns of communication, field of vision, and capacity to escape repression or reach safe spaces. The configuration of actors in a place shapes the nature of their interactions with others on the ground, possible alliances, and sources of conflict. The symbolic meanings of places shape the resonance of a group’s actions and the degree of resistance that actors face. Place in part determines the ability of activists to develop a tactic in the form that best fits their preferences.