Responding to environmental change requires a better understanding of how institutions—the rules and norms that structure human interactions—enable society to adapt to impacts of such change. By drawing on the Adaptive Capacity Wheel framework and empirical cases of coastal resource management decentralisation in the context of the Peam Krasaop Wildlife Sanctuary (Cambodia), Tam Giang Lagoon (Viet Nam) and the state of South Australia (Australia), this study examines how institutions support adaptive capacity. The characteristics of institutions analysed both facilitated and constrained adaptive capacity, depending on the enabling and disabling conditions at play. Despite the constraints, institutions have, to a certain extent, enabled actors to: organise themselves; learn and improve resource management; mobilise leadership, resources and authority; and, make progress towards improved governance. These illustrate the creation and mobilisation of adaptive capacity, which resulted in positive outcomes in responding to environmental change. In some of the cases studied, reinforcing enabling conditions of adaptive capacity will require creating livelihood alternatives, alleviating poverty, reducing inequality, and building human and social capital.