This report studies the impact of deliberative mini-publics (DMPs) on climate action and democratic governance. It presents a novel analytical framework for understanding impact, which integrates components of the RETOOL Analytical Framework (Brawley-Cheshworth et al., 2025) and the Knowledge Network on Climate Assemblies (KNOCA) Impact Evaluation Framework (Demski et al., 2024). This framework is used to carry out a systematic review of 121 articles on climate change and energy transition focused DMPs, which highlights gaps in research on the impact of DMPs on justice and accountability, as well on the impact of DMPs on expertise/ resources and thinking. The framework is also used to guide case studies of DMPs in Belgium, Sweden, and Ireland. These case studies were chosen to allow for exploration of a range of national contexts and innovations in DMP practice and are informed by semi-structured interviews and primary analysis of DMP recommendations. They explore not only the impact of the DMPs, but also the extent to which the DMPs were institutionalised or embedded into national climate governance and contributed to governance innovation. Takeaways for academics and policymakers on how to understand and enhance the impact of DMPs are presented in the final section. They emphasise the need for strong political coupling and commitment, effective and innovative communication, and careful consideration of the purpose of DMPs within democratic climate governance.