The concept of the “Specificity of Sport” is invoked in European Union law and lex sportiva to justify sport-specific rules or to modify the application of general legal rules. Nevertheless, its conceptual scope and legal effects have not been clearly articulated. This ambiguity has facilitated broad reliance on the concept to justify sporting restrictions or even to claim that sport falls outside the scope of general legal rules. Accordingly, the question arises as to the elements constituting this concept and its legal implications. Employing a descriptive-analytical method and a comparative examination of the two aforementioned legal systems, this study analyses the constituent elements of the Specificity of Sport and their legal effects. The findings indicate that this specificity is constituted by internal elements, including uncertainty of outcome and competitive balance, organisational structure, the pyramidal structure of sport, temporal constraints, the special status of athletes, and the position of supporters, as well as external elements, namely the social and cultural functions of sport. Under European Union law, these elements play a role in assessing the legitimacy of sporting rules; whereas in lex sportiva, they also affect contract law, procedural law, and competition law. The study concludes that the Specificity of Sport does not provide a basis for immunity from general legal rules; rather, it constitutes a criterion for their proportionate application. Only through identifying its constituent elements can the concept be applied as a legal standard.