In this chapter, I ask whether there are commonalities of how various upper levels attempt and often succeed in ensuring legislative implementation at the lower levels and what this means for the complex situation in which domestic legislators find themselves in today’s multi-level settings. I explain the selection of three variants of normative levels that can play the role of upper levels: 1) federal law in a federal country, 2) EU law and 3) public international law and I sketch the argument that all three of these upper levels – through a variety of conceptual manifestations – strive to ensure the effectivity of their legal sources at the lower level. Based on this premise, I then present four groups of mechanisms and instruments that these upper levels employ in order to increase the chances that lower level legislators comply. For each group of approaches, I identify the most common concerns from the perspective of the lower level. The chapter concludes with some reflections on this state of affairs and its relationship with the current backlash against international and regional law.