This chapter explores the conceptual terrain of socio-legal mobilisation in Latin America, situating local environmental struggles within broader critiques of extractive capitalism and colonial legacies. It argues that resistance to extractivism cannot be understood solely through conventional social movement theories but requires attention to relational and historically embedded processes of meaning-making, territorial defence, and legal transformation. Drawing on recent Latin American scholarship, the chapter critiques static models of political opportunity and instead foregrounds the dynamic ways in which actors frame grievances, mobilise rights discourses, and construct counter-hegemonic legal strategies. The chapter emphasises the importance of interpreting mobilisation as a dialogic and contingent process—shaped by past struggles, cultural practices, and shifting institutional contexts. It introduces the idea of “mobilising from the margins”, where communities develop legal repertoires not only to resist extractive harm but to reimagine legal orders. This theoretical groundwork underpins the subsequent analysis of how Chilean communities engage with law and legitimacy in resisting extractive frontiers.