Units

This article is considered accurate for the current version of the game.

In Hearts of Iron IV, units are the basic instrument through which the player wages war. As such, they are extremely important.

Land

Main article: Land units

Land units in Hearts of Iron IV are represented on the map by divisions. Divisions subdivide into brigades and then into battalions, and can be customized via the Division Planner. There can be a maximum of five brigades in a division and up to five battalions in a brigade. Divisions can also have up to five support companies attached to them. Known division templates at this stage of development include the iconic German panzer divisions, British tank brigades, cavalry divisions and the ubiquitous infantry division. Known brigades include light, medium and heavy tanks, infantry (both foot-mobile and motorised), cavalry, engineers, recon and artillery. Known support companies are: anti-air, anti-tank, artillery, rocket artillery, recon, engineers, field hospitals, logistics, military police, maintenance and signals.

Naval

Main article: Naval units

Naval units are represented by single ships and, unlike land and air units, are produced with shipyards. Naval units are assigned to missions in sea zones and move around sea provinces within their zone. Spotting plays an important role in naval combat. Known ship types include aircraft carriers, battleships, super-heavy battleships, battlecruisers, heavy cruisers, light cruisers, destroyers, and submarines. Like in Hearts of Iron 3, rarer ship types such as pre-dreadnought battleships or coastal defence ships have been abstracted into the previous list of types.

Air

Main article: Air units

Unlike in previous Hearts of Iron games, air units are not represented by Air Wings or Squadrons. Instead, each air unit represents an individual aircraft. Aircraft are deployed into Strategic Regions, and to obtain air superiority opposing air units in a strategic region must be destroyed. Aircraft divide into light, medium, and heavy airframes filling multiple roles, and can be customized with experience.