Hearts of Iron IV: Man the Guns is an expansion for the strategic wargame that focuses on naval warfare during World War II. This version enhances gameplay with features like convoy attacks and carrier battles, emphasizing the importance of naval innovation. Players can engage in historical battles, employing tactical maneuvers and advanced technology to dominate the seas.

Additionally, the expansion introduces alternate history paths for major democracies, providing players with the opportunity to explore different outcomes based on their decisions. This added layer of strategy allows for greater freedom in gameplay, enabling nations to act independently before the pressures of war lead to inevitable conflict.