Since the 1990s, the law and public administration have been evolving in a context marked by the profound influence of social transformations. Public authorities and services increasingly resort to policy instruments other than the law, meaning that they have an ever-growing palette of potential tools with which to orient citizens’ behaviour. As to public administrations, they no longer find themselves limited to executing their regulatory or social responsibilities; they must also participate in the development and implementation of public policies. In light of these changes, what is the law’s role today? How does the law work in conjunction with the requirements for policy effectiveness? To answer these questions, we have to place the law, its instruments and its institutions back inside the constantly shifting public administration framework, and this context requires a strategy, planning objectives and the use of public resources, all the while remaining faithful to the values of public service.To help achieve this, the course’s initial aims are to present the law’s fundamentals (legal principles, the distribution of competencies, domestic law and international law) and familiarise participants with the diversity of means - both legal and non-legal - at their disposal in terms of public action. Subsequently, the course demonstrates how legal instruments and institutions accommodate the influences of international law, public management, public policies, digitalisation and the latest advances in behavioural sciences. Finally, the course looks at the administration’s supervisory institutions.