This is United States Marine Corps Doctrinal Publication MCDP 1 Warfighting April 2018, which describes the philosophy which distinguishes the U.S. Marine Corps. The thoughts contained here are not merely guidance for action in combat but a way of thinking. This publication provides the authoritative basis for how we fight and how we prepare to fight. This book contains no specific techniques or procedures for conduct. Rather, it provides broad guidance in the form of concepts and values. It requires judgment in application. Warfighting is not meant as a reference manual; it is designed to be read from cover to cover. Its four chapters have a natural progression. Chapter 1 describes our understanding of the characteristics, problems, and demands of war. Chapter 2 derives a theory about war from that understanding. This theory in turn provides the foundation for how we prepare for war and how we wage war, chapters 3 and 4, respectively.