This article examines the remunicipalisation of Naples’ water service to explain the outcomes of participatory governance experiments inspired by commons theory. Using process tracing and Fung’s Democracy Cube, it analyses how participatory mechanisms were designed, contested and reconfigured within ABC Napoli. Based on interviews, documents and media, the findings show how legal constraints, political tensions, financial fragility and civil society–institution relationships shaped outcomes. Participatory forums evolved from open deliberation to consultative bodies with limited influence, failing to institutionalise civic participation. The study argues that both remunicipalisation and its participatory practices are hyper-local phenomena, shaped by specific contextual configurations rather than by theoretical models.