This publication focuses on the Marine Corps philosophy of command and control, planning, operations, and emerging concepts and capabilities for commanders and staff officers who are responsible for planning and executing offensive air support operations. Offensive air support doctrine first began within the Marine Corps in 1935 when the Tentative Landing Operations Manual was published and has developed over the past 65 years into today’s (MCTP) 3-20D, Offensive Air Support. This doctrine does not discuss the specifics of unit-level tactics and procedures. It provides insight as to how Marine aviation is used to shape the deep, close, and rear battlespace as an integrated combat arm of the MAGTF.