Students increasingly have access to information that can be posted by anyone without being vetted, and it becomes vital to support students in evaluating claims through debate and critical thinking. To address this issue, this paper designs and evaluates a light-weight but effective protocol for supporting debate in a classroom activity with university students. It evaluated participants’ beliefs on controversial topics (e.g., homeopathy) before and after briefly learning about critical thinking tools, posting arguments, and critically evaluating the arguments of peers. The findings suggest that this intervention led to a statistically significant belief change, and that this change was in the direction of the position best supported by evidence. Consequently, this work in progress presents a constructive approach to scaffold debates in the classroom and beyond.