This chapter introduces the relationship between law and governance. Laws and legal institutions are important in structures for governance, where governance is seen as the sum of the many ways that individuals and institutions, public and private, manage their common affairs. The description of the concept of governance used is thus not equal to governance through government, but instead reflects a system where legal institutions are seen as one part of a structural nest with multiple mechanisms, measures, and actions. International law is also increasingly characterized by a general demand for openness, transparency, fairness, and mechanisms for accountability, all part of such governance systems. Environmental governance theories propose strategies, structures, institutions, and actions that respond to different aspects of complexity and uncertainty in the environment. In this way, the theories on resilience in social-ecological systems offer a transdisciplinary perspective on effective environmental governance, where law should have a prominent role.