Recently, we have seen a dramatic increase of support for climate assemblies, especially in Europe. Choosing the remit for a climate assembly is one of the most important design factors conveners must decide on. So far, conveners seem to have followed examples of preceding climate assemblies. This has led to a prevailing model of climate assemblies assigned with remits of a broad scope, even though many in the network have expressed their concerns. Some argue, participants do not have enough time to understand and discuss the problems, the proposed measures, and their implications; or that a long list of recommendations increases the likelihood of cherry-picking. Citizens’ assemblies frequently hailed as success stories, such as the Irish assemblies on same sex marriage and abortion have had much more confined scopes. Alternative models of assemblies focussing on more specific issues of sustainability may be an alternative. The question then is: What characterises suitable remits for citizens’ assemblies on sustainability issues that aim for transformative policy and societal impact? We conducted expert surveys followed by moderated group discussions to develop a set of criteria for conveners to consider when choosing the remit for their assembly. Subsequently, we applied the criteria in Germany. Interviewing stakeholders of different climate policy areas resulted in a list of specific climate-related remits.