There are disagreements on desired roles and impacts of deliberative minipublics in democratic systems. While some are concerned about the use of minipublics as ‘shortcuts’, mini-publics can arguably have ‘deliberative impacts’ by contributing to ‘deliberation-making’ in policy processes. This paper provides a distinction between deliberative, non-deliberative and anti-deliberative impacts of minipublics. Moreover, the paper identifies factors that that need to be taken into account when maximising deliberative impacts, namely i) policymakers’ incentives to engage with mini-publics’ reasoning; ii) the format and the transmission of minipublics’ output; iii) communication and interaction between minipublics and policymakers. The paper points out that different policy-making processes entail different incentive structures, which call for different designs for maximising deliberative impacts. For example, elected representatives typically lack incentives to engage with mini-publics’ reasoning, which can be addressed by designing communication and interaction between mini-publics and representatives. In direct democratic processes, in turn, designing the format and the transmission of minipublics’ outputs is the key to maximising deliberative impacts among mass publics.