The notions of primacy and direct effect, as well as the relationship between them, influence the fundamental dynamics of the European Union legal order. Two recent judgments of the European Court of Justice, Mangold and Kücükdeveci, trigger uncertainty regarding the theoretical model underlying the effects of EU law and the circumstances in which EU law can create obligations for individuals. They constitute new landmarks for the identification of the edges of EU law. It is submitted that the Court’s novel approach, allowing for the EU principle of equality to place new obligations on individuals, is founded upon the notion of direct effect. Although the Court does not clearly elucidate why it develops the horizontal direct effect of the principle of equality, it will be suggested that the reach of this case law may be limited to specific areas of EU secondary law (such as anti-discrimination law) actually giving effect to a general principle of EU law.