The first Pacific book covers the US Marine Corps. The land and sea fighting troops of the US Naval Department; though not part of the US Navy; were closely associated with them. They were at the forefront of much of the fighting in the Pacific; bearing the brunt of many of the Japanese attacks early in the war; but eventually leading the fight during the liberation of the Pacific Islands from the clutches of Imperial Japan.

Gung-Ho also includes rules and two missions for performing Amphibious Assaults; Island Landing and Atoll Landing. The Island Landing Mission has your Marines landing on an Island without a coral reef or a lagoon; where the landing craft and amphibious vehicles come straight onto the beach. In the Atoll Landing Mission the Marines must negotiate a coral reef; then a shallow lagoon; before they hit the beach. The Amphibious Assault rules include rules for the reef; lagoon; and for getting your troops ashore; be they in Landing Craft; Amphibious LVT(4) Amtrac or DUKW trucks.