Army Doctrine Reference Publication (ADRP) 3-37 Change 1 provides guidance on protection and the protection warfighting function. It also provides the guiding protection principles for commanders and staffs who are responsible for planning and executing protection in support of unified land operations. ADRP 3-37 corresponds with the Army operations doctrine introduced in ADP 3-0 and the protection principles in ADP 3-37. The principal audience for ADRP 3-37 is commanders and staffs. Commanders and staffs of Army headquarters serving as joint task force or multinational headquarters should also refer to applicable joint or multinational doctrine concerning the range of military operations and joint or multinational forces. Trainers and educators throughout the Army will also use this manual. ADRP 3-37 outlines how protection is synchronized and integrated to preserve combat power, populations, partners, essential equipment, resources, and critical infrastructure from the effects of threats and hazards. The protection warfighting function enables commanders to preserve force combat power by integrating protection capabilities within operations. It explains how protection can be achieved and applied through the combination and integration of reinforcement and complementary capabilities. Commanders, staffs, and subordinates ensure that their decisions and actions comply with applicable U.S., international and, in some cases, host nation laws and regulations. All commanders ensure that Soldiers operate according to the law of war and the rules of engagement (see FM 27-10). ADRP 3-37 uses joint terms where applicable. For joint and Army definitions shown in the text, the term is italicized and the number of the proponent publication follows the definition. Terms for which ADRP 3-37 is the proponent publication (the authority) are marked with an asterisk (*) in the glossary; their definitions are boldfaced in the text. These terms and their definitions will be in the next revision of ADRP 1-02. Note. For the purposes of this publication, the terms threat and range of threats include enemies and adversaries. ADRP 3-37 applies to the Active Army, Army National Guard, Army National Guard of the United States, and U.S. Army Reserve unless otherwise stated. The proponent and preparing agency for ADRP 3-37 is Headquarters, U.S. Army Maneuver Support Center of Excellence.