This article analyses the legal effects and avenues for judicial control over the factual conduct of EU administrative authorities. It posits that the uncertainty that characterises the justiciability of Union’s factual conduct conceals a conceptual obscurity surrounding acts and their effects in EU law. Legal and physical acts are both means for exercising public power. To the extent that all manifestations of public power must adhere to the applicable legal requirements, the EU administration remains judicially accountable where its conduct, irrespective of how it manifests itself, has an impact on the rights and obligations of persons. The article presents an analytical framework that aims to translate the language of legal effects to a language of EU rights and obligations and vice versa. Moreover, it contextualises this inquiry within a broader threefold uncertainty that characterises EU law and illustrates the increasing significance of physical acts in the Union’s multi-layered administrative practice.