The EU has become increasingly involved in enforcing European Union (EU) law, including directly vis-à-vis private actors. (Multilevel implementation) research has so far neglected the question of what role it is necessary for the EU to play in this direct enforcement of EU law in order to promote the implementation of EU policies. Given the purpose of this collection of works to discuss innovative approaches in multilevel implementation, this contribution unravels three of the EU's direct enforcement strategies. It provides original data in relation to proliferating EU entities with direct enforcement powers and to EU enforcement networks, as well as discussing the EU's growing influence over national direct enforcement via EU hard, soft and case law. It outlines the problem-solving potential of such enforcement strategies and signals the challenges that they bring along. The aim is to urge and facilitate further research on the EU's (direct) enforcement strategies, their legitimacy, effectiveness and operation.