Chapter 3 highlights several instances of State practice where the reciprocity paradigm continues to influence belligerent reprisals. Its bearing emerges from those formalizations of the mechanism that stress the purpose of restoring the balance in rights and obligations unduly disturbed by a breach of the laws of armed conflict. The chapter will first retrace this interest in several positions expressed by States before, during, and in the aftermath of the Geneva Diplomatic Conference that led to the adoption of the 1977 Additional Protocols to the 1949 Geneva Conventions. It will then focus on the provisions of military manuals, with a particular focus on US practice and the latest Department of Defense Law of War Manual. Finally, it will provide an extensive and, under many respects, unprecedented analysis of the Italian case-law on World War II atrocities: this judicial practice, which has been revived only recently, has brought to the fore several elements that are strongly associated with reciprocity. The chapter will thus highlight notable examples in which the reciprocity paradigm contributes to defining the purpose and function of belligerent reprisals.