This article discusses how students use online role-play to collaborate and change real school policy. Playing different characters in an online role-play, students explore controversial aspects of Internet filtering and adopt a plan to change their school's policy. Through engaging in collaborative argumentation during their role-play, students identified relevant concerns, problems, and questions that were emailed to several employees of the school and district. Participating in this online role-play led students to recognize how collective action that builds on different, even competing, perspectives can lead to actual change and bolstered their belief in collaborative argument for making change in their peer group, families, workplaces, and communities. In addition to writing for collective action, the students who participated in the role-play often noted how engaged they were in the activity, not only because of the novelty of online discussion but also because of the way it pushed their thinking on issues. Based on the authors' experiences using online role-plays to foster collaborative argument in their teaching, they offer suggestions for using online role-plays. (Contains 1 figure.)