This introduction chapter presents overview of key concepts covered in subsequent chapters of this book. The book examines the regulatory balance between inclusion and exclusion in competitive sport. It analyses a range of legal and non-legal cases concerning sex, gender, disability and race to identify when sporting exclusion is justifiable for the protection of the essence, and when it is unjustifiable and incompatible with equality legislation. The essence of sporting activity is concerned with challenging one's physical and non-physical differences by creating conditions which separate winners and losers on the basis of these differences. The core of competitive sport is ultimately about being the best athlete, however, it is a contested realm where positive and negative values continually conflict and contrast with each other. The compatibility of sport rules and actions with legal rules will be critiqued such as sports rules which restrict the fundamental freedoms of individuals but that are considered necessary for the greater good of sport.