This special issue of the Swiss Journal of Sociocultural Anthropology focuses on assembly practices as a tool for collective decision-making within human groups that claim multiple forms of political autonomy from States. The aim of this dossier is to ethnograph decision-making processes in various social spaces, both in a post-colonial indigenous context (Amazonia, Andes, North America) and in a Western European social movement (Spain). The description of these meetings reveals a multiplicity of strategies that people invent and implement in order to decide together, form a political union and try to build a society on terms that are distinct from those that characterize the state model. In doing so, these ethnographies invite us to reconsider the conceptual tools of anthropology for thinking about the political.