This chapter examines the basic functioning of selective law enforcement and utilizes various typologies and perspectives to confront its hybrid character head on. How exactly should we understand the interactions between legal and extra-legal components? The selective enforcement of law challenges some of the core assumptions of the mainstream approaches to institutional interactions. The discussion concludes that the informal component of selective law enforcement essentially enjoys a parasitic relation to its ‘host’ institution, which makes it dependent upon both the host's strengths and its weaknesses. The chapter also lays out the mechanics of selective law enforcement as a mechanism to enforce informal rules. This approach has wide reaching implications, not least concerning rule promulgation and deterrence. Using this argument, the chapter also posits that the political and legal issues of a given case can be understood as two different rule propositions. The ambiguity of the practice stems from the overlap and conscious entanglement of these rules. By putting this ambiguity to use, manipulators can play upon both political and legal discourses opportunistically to distort and deflect criticism.