User interface

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Revision as of 19:21, 11 June 2016 by Bridger15 (talk | contribs) (Formatted a few things, provided overview of menus and link to new page (hotkeys))
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The user interface of Hearts of Iron IV will be immediately familiar to veterans of Paradox strategy games. The left hand of the screen will be used to manage large national issues, alert tabs will appear at the top of the screen as a warning of things that need attention, and the right hand side of the screen will be devoted to information about troops. The very top border of the screen will include important summary information about the state of the game and the world.

Top Information Bar

Across the top left to center of the main play screen, there is a row of numbers running from left to right.

National unityNational unity
The measure of a nation's war-resolve. A country with low national unity will surrender more quickly than one with high National Unity. National Unity is determined by National Spirit traits that can be assigned to certain countries (France, for example, starts with very low NU), but it can be modified through National Focus choices or recruiting government officials to modify it.
Political powerPolitical power
This is the amount of political capital the nation's leadership has accumulated. Political power can be spent on completing national focus ideas, recruiting military and scientific advisors, changing trade and conscription laws, and some diplomatic actions. Each nation gets 2 points of political power per day, modified by certain traits, individuals, player actions or characteristics.
The number of men available to create and reinforce military units. This is affected by a number of factors, primarily mobilization laws and the number of units under construction.
Three separate numbers, listing the military factories, naval dockyards and civilian factories available for new orders. We will deal with their roles in a future section.
ArmyArmy, NavyNavy and Air experienceAir experience
As units fight or, in the case of armies, exercise, they will gain experience. Army experience can be spent in the unit designer to edit or invent land divisions. Naval and air experience can be spent on modifications for ships and planes, giving them bonuses to speed, firepower, and so on.
The number of convoys or transports that are available. Each trade for strategic resources requires the allocation of a convoy unit. Moving land units across oceans and seas requires an allocation of transports. The number of available transports can be increased by building new convoys in the unit production menu.

World tension

To the upper right of the screen there is a glowing circle with a percentage below it, indicating the world tension. This percentage is the measure of how much tension is in the world. Some diplomatic and military actions, especially for democratic or neutral nations, require the world tension to reach a specific level. World tension is increase by historic events, declarations of war, and other hostile diplomatic actions.

Main Menu Bar

Qwertyui hotkeys.png

The Flag and 7 grey buttons just underneath the top bar provide direct access to the primary menus you'll use to interact with your country. The hotkeys for these menu buttons are noted above. They follow, from left to right, across the top row of your keyboard. The windows they open are detailed below.

National information and development

To the far left of the screen the player nation's flag is shown. Click this flag to open a view of national status. This view shows a portrait of the nation's leader, political support and parties, some active variables and factors for the nation, and three rows of items that political power can be spent on.

Political screen.

You will be prompted to choose a national focus for your country. It takes 70 days to complete a national focus, and it costs one political power point per day. National Focuses are similar to research tech trees in other games, except they are connected with choices your country is making about its direction. It may choose to, for the moment, focus on industrial growth, or, in the case of Germany in most games, push for expanding its borders at the expense of its neighbors. Some National Focus choices are mutually exclusive; the Soviet Union cannot be friends with both China and Japan.

National focus tree of Italy. (Click to enlarge.)

From this menu, you can also spend political power on changing government laws or hiring political, military and industrial advisors. Most changes will cost a minimum of 150 political power, very powerful advisors may cost up to 250.


  • Conscription law: affects how much manpower is available to your country
  • Trade law: affects research speed, factory and construction speed and how many resources are available to be traded
  • Economy law: affects how many factories are dedicated to consumer goods, manpower availability, and military production

You also have space for three political advisors you can hire to give you bonuses

Production and research

You can add a tank designer, ship designer, aircraft designer and material designer to earn bonuses to either production of the relevant weapon system, or affect its combat abilities.

You can also add an industrial concern and a theorist to improve certain types of research.

Military staff

You can add a Chief of Army, Chief of Navy and Chief of Air Force to improve research or combat skills in the relevant field. You may hire up to three other members of your high command.

Political Advisor screen.


The gray button at the top of the screen marked with a beaker opens your research menu. You will have three or four slots available to research particular technologies, but if you pursue specific national focus ideas you may unlock additional research slots.

Research screen.

There are eleven categories of research. Each nation starts with an historically appropriate level of technology and theory, depending on the scenario.

All the research trees (except for doctrines) are marked along an historical timeline. Researching a technology or unit before the historic date will take longer than it would if you researched it at or after the historic date. This penalty may be modified by pursuing certain National Focus ideas.

Infantry: researching better infantry weapons and different types of infantry divisions. This is where you will go to unlock mechanized infantry, paratroopers, marines, mountain troops and so on.

Infantry technology screen.

Support: researching support battalions that you can attach to your divisions. This is where you will find engineers, medics, mechanics, and so on. Tanks: research light, medium and heavy tanks, as well as variant tanks based on the chassis you unlock. Artillery: researching artillery, anti-tank and anti-aircraft weapons.

Land doctrine: Most of the great powers will start with an initial land doctrine. You may change this, but all land doctrine paths are mutually exclusive. The land doctrine you choose will assign major combat bonuses.

Land doctrine screen.

Naval: researching more advanced warships, submarines and convoy/landing craft.

Naval doctrine: Some of the great powers will start with an initial naval doctrine. You may change this, but all naval doctrine paths are mutually exclusive. The naval doctrine you choose will assign major combat bonuses.

Aircraft: researching different types of fighters, attack planes and bombers as well as carrier borne variants.

Air doctrine: Some of the great powers will start with an initial air doctrine. You may change this, but all air doctrine paths are mutually exclusive. The air doctrine you choose will assign major combat bonuses.

Engineering: researching electrical engineering for radars (for detection) and computers (for research and encryption bonuses), as well as researching nuclear and rocket technology

Industry: researching means to improve the efficiency, productivity and resource extraction capabilities of your country.


The gray button with a hand ready to be shaken opens your diplomacy menu. Here you will see a list of nations and a number of filter buttons to narrow down the list.

When you click on a nation you want to interact with, you will see a portrait of the leader, and a little bit of information about what the nation is up to. In the upper right corner of the menu, you will see a couple of tiny flags with arrows indicating the relationship between your two nations. There are a number of actions you can take in the diplomatic menu, provided you meet the requirements. Democracies are especially limited in their abilities to undertake aggressive diplomatic actions unless the world tension meter has climbed to a high enough level.

Hover your mouse over each option for a description of the diplomatic action and what conditions must be met.


The gray button with box and curved exchange arrows opens your trade menu. You will see a number of tabs and columns listing the major resources available, what you require and possible trading partners.

There are six major resources in the game: oil, rubber, aluminum, steel, chromium and tungsten. These are used to help in the construction tanks, battleships, planes and so forth. Each new production line of a major weapon system will require a certain amount of resources. Though you can build these units without the necessary resources, your production will be much slower and less efficient.

File:Trade screen.jpg
Trade screen.

Resources are found in certain locations on the map and are not evenly distributed. You will almost always have to trade for what you need.

To trade for a resource, click on the name of the country and move the slider to determine how much you are trading for. Resources are traded in units of 4. Each trade, unless conducted over land, requires a minimum of 2 convoy vessels plus 1 for every additional 4 units of resource.

Every four units of a resource you import will also cost you a civilian factory, with that productive power going to the nation you are trading with. So, exports will make your industry stronger as you pull factory power from other nations, but a lot of imports will make you weaker. But you will need to import resources to keep your war machine going.


The gray button with the crane opens your construction menu. This is where you will assign tasks to your civilian factories - building infrastructure, new factories, defenses, and so on.

Civilian factories make all the improvements to a territory. The number factories you have available for construction will depend on the size of your nation, how many factories are being dedicated to providing consumer goods for your country (your Economy Law), and how many factories you have “traded” for strategic resources. You can increase your number of civilian factories by building more, but be careful since each province can only support a certain number of productive structures. A maximum of fifteen factories will be devoted to a construction project, and any left over will work on the next item in the queue.

Constructions screen.jpg

There are three categories of structure you can build with civilian factories.

State structures:

  • Infrastructure: Each territory has an infrastructure rating that determines how easy it is to supply units in the territory and how quickly military units can move through.
  • Airfields: Airfields house your military aircraft. The larger the airfield, the more planes it can effectively field.
  • Anti-aircraft: Defends a territory from enemy aircraft, and especially useful to protect industrial areas
  • Radar stations: Help your aircraft detect and intercept enemy air fleets.

Shared structures:

The number of shared structures that can be built is limited by the number of slots available in that State. The number of slots can be increased by researching Industry technologies.

Province buildings:

  • Naval port: Assists in oversea supply limits and ship repair speed
  • Forts: Hardens the defense of units
  • Coastal fort: Hardens the defense against amphibious attacks

Province buildings are built on the smallest territory size in HoI4, the province.


The gray button with the wrench opens your production menu. This is where you assign military factories and dockyards to build equipment, army vehicles, ships and aircraft.

The more factories you dedicate to building a specific item, the more you will produce. Infantry, armor and artillery units you make will then be assigned to the appropriate military divisions, either for new units you are constructing or reinforcement and upgrades for units in the field. Airplanes you produce will be deposited into a reserve pool. Naval units will be automatically placed in a port, though you can assign one if you would rather.

Factory output is dependent on the availability of strategic resources for higher end units, and on the efficiency cap of your industry. New production lines will take time to be perfectly efficient, and if you add factories to a production line, you will lose some of that efficiency. You can raise your factory productivity and efficiency in the Industrial research tree.

Recruit and deploy

The gray button with the tank opens your army planner menu to recruit and deploy units. This is where you decide what types of divisions you want to train. These divisions will be filled by the equipment and vehicles you build in the production menu. You can see what is required to complete a new unit by hovering over the green progress bars.


You start with a few default divisions you can build. You can spend army experience to design new division templates or edit ones that already exist.

The game starts with reinforcement and upgrades given equal weight with the creation of new units. If you would rather focus the energy of new tanks or artillery on fresh units, instead of trickling equipment to the field, you can set your reinforcement priorities on this menu as well.


The gray button with the paper and pen opens your logistics menu. This menu gives you an overall summary of your stockpiled equipment, whatever shortages you might have, as well as a rundown of how many strategic resources you are missing from your production lines.