Practices of citizen deliberation have become increasingly popular across Western democracies over the past couple of decades. These may take a wide range of forms, each serving different purposes and interests, and producing different outcomes. Mini-publics are among the most common and widely used deliberative democratic innovations: they can be defined as “independent and facilitated group discussions among a (near) random sample of citizens who take evidence from experts and interested parties” (Smith and Setälä 2019: 300). Different types of mini-publics coexist and imply variation in terms of the number of participants, the number of meetings, the planned output and material costs.The main objective of this methods brief is to give a short explanation of what mini-publics effectively are, and to identify the challenges and opportunities they entail. While they should not be conceived as the solution to all policy problems and there are no ‘one-size-fits-all’ models of mini-publics, they offer innovative ways to investigate complex issues and how these are understood by citizens. The methods brief introduces a multi-level mini-public experiment (what we dub ‘the REGROUP model’), in which participants in citizens’ juries have the opportunity to formulate policy recommendations on knowledge communication, disinformation, the role of experts in policy-making and political trust at the domestic and European levels.