Climate assemblies are intended to lead to real change that addresses the climate emergency. As such, it is critical to establish an understanding of the types of impact and legacy that can arise from them, and to be able to plan for and evaluate their outcomes. Drawing on a rapid evidence review and interviews with experts on climate deliberation, the paper presents a framework for exploring the impact and legacy of climate assemblies that distinguishes timescale, objectives and strategy, areas of influence and types of outcome.