This eighth edition of The Marine Officer’s Guide continues in the tradition of its predecessors. As Colonel Robert D. Heinl, Jr., one of its originators noted, the Guide aims “to assist new officers to learn the ropes as quickly as they can, to digest for all readers the continuing changes which have beset the Defense Establishment, and to help the entire officer corps keep professionally up to date.” To that end, this newly revised edition has been reorganized the into three parts. After the largely intact introductory chapter, Part I addresses the Marine Corps as a military service, an institution, and, yes, in some degree, a bureaucracy. This part touches upon the Corps’ storied history; places the service in the nation’s defense and naval establishments, the treatments of which are completely updated; describes its mission, organization, and infrastructure; and reveals inter alia its culture, the sum total of its beliefs and ways of thinking, working, and behaving. This part also includes a refined and expanded discussion of the Marine Corps’ fundamental organizing construct, the Marine air-ground task force (MAGTF), with new illustrations providing greater detail on the components of each element of the MAGTF. Additionally, Part I contains a current and detailed discussion of the Marine Corps’ basing infrastructure, which now falls under the command of the new Marine Corps Installations Command (MCICOM). Part II turns to topics related to becoming and being an effective officer of Marines. Most important here are discussions of leadership and the profession of arms, but the updated and expanded chapters on such mundane but essential topics as unit and individual administration, pay and allowances, and military justice are also worth the effort. Finally, Part III provides useful information on personal, family, and social matters, incorporating the very latest information on pay, entitlements, and health benefits. In sum, this new edition is current and applicable to today’s Corps.