Hearts of Iron IV

Hearts of Iron IV is a single-player and multiplayer grand strategy game. The game is set during the period of the Second World War and allows players to take control of any nation in the world. Starting in either 1936 or 1939, the player assumes leadership over political, military, and economic systems, guiding their chosen country through the turbulent years of global conflict. Victory can be pursued through military conquest, alliances, technological dominance, or ideological expansion, with alternate history outcomes possible depending on decisions made.

At its core, the game focuses on the management of armies, navies, and air forces. Players design and organize divisions, command fleets, and assign aircraft to missions ranging from strategic bombing to close air support. Combat takes place across a detailed world map divided into provinces and regions, where supply lines, weather, and terrain influence outcomes. Frontlines and battle plans can be drawn directly on the map, letting players set objectives for their generals and adjust strategy dynamically.

Production and logistics form another essential system. Military factories, dockyards, and civilian industry are allocated to produce weapons, tanks, aircraft, and ships. Players must also manage natural resources such as oil, steel, and aluminum, which are required for modern war machines and can be obtained through trade or conquest. Research unlocks new technologies, doctrines, and equipment, while national focuses provide structured goals that shape both short-term strategy and long-term development.

Diplomacy and ideology are key components of progression. Nations can align themselves with major factions such as the Allies, Axis, or Comintern, or create new alliances. Government systems can shift between democracy, fascism, communism, or neutrality, affecting both domestic policy and foreign relations. Political power is spent on advisors, laws, and decisions that alter the country’s abilities and trajectory.

Occupied territories may resist foreign control, requiring garrisons or political measures to suppress unrest. Intelligence allows for code-breaking, reconnaissance, and covert operations that provide advantages in both diplomacy and warfare. Weather and seasons add further complexity, as winter campaigns or tropical climates can stall offensives or drain supplies.

Multiplayer supports large-scale matches where several players manage different nations simultaneously, working together or competing in a dynamic conflict. The game is designed to allow both cooperative play within factions and adversarial matches.