Hearts of Iron 4 Even on Easy Game is Really Hard

This guide is intended as a beginner's tour of the interface and mechanics in Hearts of Iron IV. For more detailed information on the mechanics, including some of the detailed math behind some of the computer's calculations, follow the links to the articles dedicated specifically to those concepts.

Before Clicking the Game Play Button [edit | edit source]

It may be a good idea to become familiar with the information displayed, the various button and tab names, and the functions of those buttons and tabs before clicking the game Play button.

The Launcher for Hoi4. Items 1 through 7 are as follows: 1) game version and checksum 2) video display button 3) clear user directory button 4) game play button 5) create account button 6) downloadable content (DLC) tab 7) mods tab. Note that the DLC tab is currently open.

Game version - Observe that the graphic shows game version 1.11.12 and checksum 22d5. Saved games are set to the game version and checksum that are currently playing. If the saved game version and checksum do not match the game version and checksum, then the saved game will not work. Be aware that the game is normally on automatic updates and once By Blood Alone (version 1.12) is released, then version 1.11.12 saved games will not work unless the game is rolled back to the matching version. This rollback procedure can be found on the Paradox Forums. Note that this procedure requires a game code for each owned game branch and that a Paradox Interactive account is needed to view those codes for input into Steam.
Video display button - Clicking the gear icon opens the video display menu. This menu has 3 dropdown menus; Display Mode, Resolution, and Refresh Rate. The Display Mode allows three choices: Fullscreen, Windowed, and Borderless. Fullscreen is recommended because Windowed and Borderless modes on some systems have been known to cause launch issues such as blackscreens and failure to launch the game (reference Troubleshooting the game). The Resolution allows a multitude of choices such as 1600x1024, 1680x1050, etc. Matching the game's resolution to the monitor's native resolution usually gives the optimum viewing experience. The Refresh Rate should also be set to match the monitor, if possible. The 60 Hz selection is recommended because it is quite common and the 50 Hz selection has been known to cause launch issues such as blackscreens and failure to launch the game.

This graphic has a vertical arrow pointing to the video display button represented by the gear icon. Clicking the "gear icon" will open the video display menu (see horizontal arrow) revealing 3 dropdown menus; one menu each for Display Mode, Resolution, and Refresh Rate. Clicking on each small, inverted, green triangle will open a menu for choosing your video preference. The graphic shows that Fullscreen, 1920x1080, and 60 Hz have been selected.
Clear user directory button - Clicking on this button will clear your HOI4 user directory. Only click on this button if you are experiencing game crashes. Reference the Tooltip in the graphic.

A graphic with arrows pointing to the "Clear user directory" button and its associated Tooltip.
Game Play button - Click the game Play button after choosing the video settings, DLC, and mods.
Create Account button - Click this button to create a Paradox Interactive account. It is recommended that you create an account as it will give you access to technical support in the event that the game becomes problematic. A Paradox Interactive account is also needed to log into the Paradox Plaza website to access the codes for previous branches of each game that is owned. This is due to the enactment of the General Data Protection Regulation (GDPR). Other benefits include access to bug reports, game suggestions, etc.
DLC tab - Clicking on the DLC tab will reveal all of the downloadable content purchased for this game. Clicking an item will place a green check mark next to the item indicating that it has been selected for inclusion in the game. No check mark indicates that the item was not selected for the game. The graphic shows that all purchased items (Anniversary Pack, Historical German Portraits, Poland: United and Ready, Rocket Launcher Unit Pack) have been selected. Note also that such DLC as Together For Victory, Death or Dishonor, and Waking the Tiger are not shown in the graphic as this user did not purchase those items.
Mods tab - Clicking on the Mods tab will show a pulldown menu capable of revealing all of the mods that have been downloaded for the game. Clicking an item will place a green check mark next to the item indicating that it has been selected for inclusion in the game. No check mark indicates that the item was not selected for the game. The graphic shows that the mods "Coloured Buttons" and "More Division Icons" have been selected. Mods can be downloaded from the Steam Workshop. Be aware that some mods will deactivate the ability to get achievements during gameplay and that some mods are not updated for the latest version of the game which can lead to a system crash. Reading the author's information about their mod will usually indicate if the mod is compatible with achievements and what version of HOI4 that their mod has been updated to.

A graphic with an arrow pointing to the "Mods" tab. The "Coloured Buttons" and "More Division Icons" mods have been selected.

Troubleshooting the game [edit | edit source]

Try the solutions listed below if the game fails to launch, freezes, crashes to desktop (CTD), or "blackscreens". The most common causes and solutions are listed first. Contact technical support or visit the forums for additional help. A Paradox Interactive account is required to contact technical support.

Some anti-virus programs will automatically block executable files: try adding hoi4.exe and steam.exe to the anti-virus exception list.

Outdated graphics card drivers: try downloading and installing the latest drivers for the graphics card.

Incompatible OS settings: try Windows compatibility settings by navigating to the hoi4.exe file (typical file path C:\Program Files (x86)\Steam\SteamApps\common\Hearts of Iron IV), right clicking on the hoi4.exe file, clicking on Properties, clicking on the Compatibility tab, and experimenting with the different settings.

Incompatible graphics card settings: try running the game on Fullscreen instead of Windowed mode. From the game launch screen, click the gear icon to open the video display menu. This menu has 3 dropdown menus; Display Mode, Resolution, and Refresh Rate. The Display Mode allows three choices: Fullscreen, Windowed, and Borderless. Choose the Fullscreen option.

Incompatible graphics card settings: try manually editing the settings.txt file by first navigating to the settings.txt file (typical file path C:\Users\Documents\Paradox Interactive\Hearts of Iron IV\settings.txt). Then open the settings.txt file and manually change the text to read as follows: fullScreen=yes and borderless=no. Caution: Only change the fullScreen and borderless text settings. Do not change or erase the other settings unless you backup your file and know what you are doing.

Corrupt user files: Try clearing the user directory. From the game screen, click on the "Clear user directory" button. Then exit the game and relaunch it.

Corrupt game files: Try a clean reinstallation of the game.
- Move your important game files to a backup folder.
- Go to Steam and select the Hearts of Iron IV game from the Steam Library, then right click and select Uninstall...
- Navigate to C:\Program Files (x86)\Steam\SteamApps\common and manually delete the Hearts of Iron IV folder.
- Navigate to C:\User\Documents\Paradox Interactive and manually delete the Hearts of Iron IV folder.
- Go to Steam and select the Hearts of Iron IV game from the Steam Library, then click Install. Do not launch the game yet! Stay on Steam!
- While still on Steam right click the Hearts of Iron IV game, select Properties, click on the LOCAL FILES tab, then click on the VERIFY INTEGRITY OF GAME FILES button. This will validate the game files just installed. An "All files successfully validated" message should be seen.
- Start the game with no mods active.
- Test the game

Starting the game [edit | edit source]

Single player offers the one-player game of Hearts of Iron IV. All other countries will be controlled by the computer. The Single Player menu allows for playing the Tutorial or to start a new game as well as to load a previous saved game.

Playing the Tutorial gives a quick run-down of the game and is therefore highly recommended. The Tutorial game may be continued as if it was a standard playthrough after finishing it.

Multiplayer enables Hearts of Iron IV players to play online with other people. Up to 32 players may play (both competitive and cooperative multiplayer) in one game of Hearts of Iron IV at the same time. The host of the game is able to start a fresh game or load a previous session that was not completed.

Options allows for the customization of sound, appearance and gameplay details of Hearts of Iron IV. This includes adjustment of monitor resolution and user preferences for graphics and sound. The first tab includes very important "game settings."

Once through basic setup, the player may choose a scenario and a nation to play for the duration of that play session.

The world in 1936 [edit | edit source]

The 1936 scenario begins on January 1, 1936. The 1936 scenario is the one most likely to lead to alternate versions of World War II, since it starts with fewer alliances or wars to start. 1936 is the place to begin in order to play through the organization and planning of an economy before the war starts. This scenario is about laying the groundwork for the armed forces and war plans, opening with a focus on production, research and diplomacy.

Choosing a nation [edit | edit source]

Each scenario displays a menu with the seven major powers ( France, the United States, the United Kingdom, the German Reich, Italy, Japan, and the Soviet Union) as well as any countries with enabled DLC updates. No matter which is selected, a map of the world is then displayed to allow for change in the choice. The player may select whatever country they wish, but one should be aware that countries like Bhutan may not be best suited as the first nation to play as. We recommend any nation you believe you know the most about, or what will be the most fun!

Game settings [edit | edit source]

In the lower right corner of the map before starting the game are the game settings. Here the player can toggle ironman and historical focus on or off and use the difficulty settings to make the game harder or easier for the player and also boost the relative power of one or more of the more important nations (this makes them stronger, but not smarter). There is also an icon for showing if steam achievements can be earned in the game or not, they require ironman mode and regular or higher difficulty. When finished press the play button in the lower right hand corner to start the game.

Difficulty settings [edit | edit source]

Main article: Difficulty

Players have the option to define a general difficulty which will apply modifiers globally to themselves and/or the AI. In addition, a player may also apply different modifiers to the seven major countries, thereby buffing/debuffing only one entity and the front it plays in.

The interface [edit | edit source]

Main article: User interface

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 [edit | edit source]

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

Political power: This is the amount of political capital the nation's leadership has accumulated. Political power can be spent on completing national focus ideas, appointing ministers (political advisors, designers, theorists, and military staff), taking decisions, changing trade laws, economy laws, conscription laws, and some diplomatic actions. Each country gains +2 ^[1] points of political power per day which can be modified by Nation Leader traits, Political Advisors, Stability, National Spirits, National Focus selection, Political Events, Political Decisions, or player actions.

Stability: The measure of the people's support for its government. A country with low stability suffers penalties to factory and dockyard output, political power gain, and consumer goods while experiencing an increase to occupied territory resistance gain. The average stability is 50%. A nation with 50% stability does not gain nor lose anything. Stability above 50%^[2] yields positive modifiers related to factory and dockyard output, political power, and consumer goods while stability below 50%^[2] yields negative modifiers in those categories.

War support: The measure of the people's support for war. War support directly affects mobilization speed, Command Power gain, and attack and defense on core territory. Fascist and aggressive nations generally have more initial war support, but they can eventually be surpassed by democracies fighting a defensive war. Countries gain a positive war support buff for being in a defensive war and a negative buff when being in an offensive war. War support is also affected by world tension, Pride of the Fleet, enemy bombing, allied interception, enemy convoy raiding, heroes being killed in action, and operative propaganda. Nations with low war support tend to surrender quicker.

Manpower: The number of men available to create and reinforce military units. This is based on the territories under the nation's control (core and occupied giving different manpower yields) and affected by a number of factors, primarily conscription laws, National Spirits and the number of "units under construction", also known as units under recruitment.

Factories: 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.

Fuel: Fuel is generated by the nation's excess oil. Each nation has a maximum capacity for fuel which can be increased by building silos and infrastrucure. Fuel generation is affected by oil available (domestic and traded), research, and economy laws.

Logistics Fulfillment: Logistics Capacity (Fulfillment) represents how satisfied your supply lines are. If your country lacks the trains, trucks, or convoy ships for transferring all supply needs, then your units will get reduced supply which can result in supply penalties.

Convoys: The number of convoys, also known as transports, that are available. Each trade for overseas strategic resources requires the allocation of convoy units. 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.

Command power: Command power represents the ability of the government to bypass the chain of command and directly influence the military. Command power is used for various military operations and promotion of generals. It is capped at 200^[3], however, the growth and cap can be increased by Doctrines and National Spirits. Command power is limited to promotion of Field Marshals unless you have the Waking the Tiger DLC.

Army, Navy and Air 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 division templates or modify tank and tank variant equipment. Air experience can be spent on modifications for planes, giving them bonuses to speed, firepower, and so on. Naval experience can be spent on modifications for ships, or, with the Man the Guns DLC, to be spent in the ship designer to create new ship patterns or upgrade old ones.; All three sorts of experience can be spent to gain research speed boosts, at a rate of 100 XP for a 100% research speed bonus for land, air and naval doctrines, respectively. Naval XP may be used to get a 50-150% research speed bonus for certain naval modules.

Nuclear weapons: When nuclear weapons are researched, an icon with a number will appear in the top information bar showing the amount of nuclear bombs a country has available.

World tension: To the upper right of the screen there is a globe with a percentage below it, indicating the level of world tension. This percentage is the measure of how close the world is to world war. Some diplomatic and military actions, especially for democratic or neutral nations, require world tension to reach a specific level. World tension is increased by historical events, declarations of war, and other hostile diplomatic actions. The globe can be selected and the Player can access a list of events affecting world tension and a list of ongoing wars.

Primary map modes [edit | edit source]

Land Map Mode - Comprises the following three levels of detail and is the mode that will be seen during the majority of game play. Also known as Default Map Mode.

Nations represent the land borders of countries. Interactions with nations occurs within the scope of diplomacy. Nations have names.

A nation is comprised of states. Factories, infrastructure, and most other improvements built using Civilian Factories are done at State level. Each state is limited in how many improvements it can have. States also have names.

Within each state are provinces. Interaction with provinces is largely done via land units and a set of constructions that generally aid those units - i.e., forts and naval bases. Provinces do not have names unless they are worth a special amount of victory points and their details are visible in the bottom section of the state overview screen.

There are three other map modes that players use and whose definitions of Region or Area largely ignore national borders and potentially encompass multiple states.

Naval Map Mode - Sea regions of which up to three adjacent ones can be selected when giving orders to naval fleets. Totally independent of the land map mode. Sea regions all have names.

Air Map Mode - Overlays the land and sea map modes. Air bases are assigned operational concern over a given Strategic Region and air wings are given missions. The air base will then have its planes perform their missions within the strategic region. Strategic regions also have names.

Supply Map Mode - In the new update, The supply is now reworked to be built around rail systems. There are also supply hubs and a color map to show if it can support your troops on that state.

All three of these regions use blue/green/yellow/red border highlighting to indicate neutral/good/moderate/bad conditions in the region relative to either supremacy (land/sea) or sufficiency (supply).

World tension [edit | edit source]

Main Menu Bar [edit | edit source]

The Flag and 9 icon buttons (10 with La Résistance ) to the immediate right of the Flag provide direct access to the primary menus for interaction with your country. The hotkeys for these menu buttons are noted below. They follow, from left to right, across the top row of the keyboard.

Qwertyui hotkeys.png

Hotkey	Q	Shift+Q	Shift+W	W	E	R	T	Y	U	I	Shift+E
Opens	Government	Decisions	Intelligence agency	Research	Diplomacy	Trade	Construction	Production	Recruit & Deploy	Logistics	Officer Corps

National information and development [edit | edit source]

To the far left of the screen is the national flag. Click on this flag to open a view of national status. This includes a portrait of the national leader, political system and level of support for each of the four ideologies, the National spirits that currently apply, and three rows of items that can be changed by spending political power. The view includes buttons for managing occupied territories, exiled governments and subjects.

The player will be prompted to choose a national focus for the country if none is active. It normally takes 70 days to complete a national focus, and it costs one political power point per day. National focuses form a tree, like the technology tree, but rather than unlocking technology they are about the country's choice of direction. One may choose to, for the moment, focus on industrial or technological growth, or orient the country's diplomacy towards certain other countries, forming research pacts, starting factions, gaining claims, or threatening war. Some National Focus choices are mutually exclusive; for example, the German Reich cannot be friends with both China and Japan.

This menu also allows political power to be spent in order to change government laws or hire political, military and industrial advisors. These are summarized under the term ideas. Most changes will cost a minimum of 150 political power, and very powerful advisers may cost up to 250, with extremely powerful laws and advisers costing up to 300 political power and sometimes even more than that.

Laws & Government

Conscription law: Affects how much manpower is available to the country for military service, factory output, dockyard output, construction speed, and training time
Trade law: Affects resources to market, factory output, dockyard output, construction speed, and research time
Economy law: Affects how many factories are dedicated to consumer goods, manpower availability, civilian and military factory construction speed, and conversion speed for factories

Up to three political advisors can be hired to give the country bonuses in different fields.

Research & Production

There are multiple design companies that can be added, such as a tank designer, ship designer, aircraft designer, material designer and industrial concern, to earn reductions and bonuses for the relevant field. These bonuses can include any combination of a reduction in research time, an increase in equipment production, or an increase in equipment combat abilities.

It is also possible to add a theorist to reduce doctrine experience costs, to reduce costs for rocket research or nuclear research, or to increase max speed by 10% for armor equipment.

Military staff

As military staff, a Chief of Army, a Chief of Navy and a Chief of Air Force can be hired to improve combat stats in the relevant field. Up to three other members of the high command may be hired.

Decisions [edit | edit source]

The gray button at the top of the screen marked with a gavel opens the Events and Decisions menu. Decisions allow a nation to do special projects such as switching ideology, conducting border wars, banning political parties, censoring the press, excavating for resources, etc. These decisions typically cost anywhere from 25 to 150 political power. Decisions are a middle ground between focus trees and events (allows additional modding and mechanics).

Intelligence Agency [edit | edit source]

The gray button at the top of the screen marked with an eye opens the Intelligence Agency menu. Establishing an Intelligence Agency allows a nation to recruit operatives (spies), expand intelligence capabilities, and conduct intelligence operations (espionage missions).

Research [edit | edit source]

The gray button at the top of the screen marked with a beaker opens the research menu. There will be two to four slots available to research particular technologies, but pursuing specific national focus ideas may unlock additional research slots.

Each nation starts with a historically appropriate level of technology and theory depending on the scenario. All the research trees are marked along a historical timeline. Researching a technology or unit before the historic date will take more days than if it had been researched at, or after, the historic date. This penalty may be modified by pursuing certain National Focus ideas.

There are eight categories of research. Note: Doctrines are no longer part of the research tree with the release of patch 1.11.0 Barbarossa.

Infantry: research better infantry weapons and equipment and unlock specialized types of infantry divisions. This is where mobile infantry (motorized infantry and mechanized infantry), paratroopers, marines, mountain troops, trucks, motorized rocket artillery (MRA), amphibious vehicles (requires Man the Guns DLC), and armored cars (requires La Résistance DLC) will be unlocked.

Infantry technology screen - outdated (doctrines removed from research and added to officer corps with patch 1.11.0 Barbarossa).

Support Companies: research support equipment and improve support companies that can be attached to divisions. This is also where engineers, recon, military police (MP), maintenance, field hospitals, logistics, and signal companies can be unlocked. Train engines and railway guns can be unlocked with the No Step Back DLC.

Armor: research that unlocks and improves light (LARM), medium (MARM), heavy (HARM), super heavy (SHARM), and modern battle tanks (MBT), as well as their variants: tank destroyer (TD), self-propelled artillery/gun (SPART or SPG), and self-propelled anti-air (SPAA). With the No Step Back DLC, the panel consists of various tank chassis technologies as well as individual module technologies ranging from armor plate to engines.

Artillery: research that unlocks and improves all types of artillery including anti-tank (AT), anti-air (AA), and rocket artillery (RART). With the No Step Back DLC, the panel consists of various tank gun module technologies ranging from small cannons to advanced high velocity cannons to auto loaders.

Naval: research that unlocks and improves ships: destroyer (DD), light cruiser (CL), heavy cruiser (CA), battlecruiser (BC), battleship (BB), superheavy battleship (SHBB or BBB), carrier (CV), submarine (SS), or transports for naval invasions. With the Man the Guns DLC, the panel consists of Destroyer (DD), Cruiser (CL,CA), Heavy Ship (BB,BC), Carrier (CV) and Submarine (SS) hull technologies as well as individual module technologies, ranging from guns to special equipment, to special naval training.

Air: research that unlocks and improves aircraft: fighter (FTR), heavy fighter (HFTR), close air support (CAS), naval bomber (NAV), tactical bomber (TAC), and strategic bomber including carrier borne variants and jet propelled versions.

Engineering: research electrical engineering to improve or unlock radio (for reinforce rate bonuses and signal companies), radars (for detection bonuses), and computers (for encryption and decryption bonuses), research atomic energy to unlock nuclear reactors and nuclear bombs, and research experimental rockets to unlock and improve rocket engines (for rocket interceptors and guided missiles) and jet engines (for jet aircraft).

Industry: research that improves military factories and dockyards (for output, production efficiency and retention, military equipment conversion speed (requires Death or Dishonor DLC), factory bomb vulnerability and repair speed), construction speed (for faster building), resource extraction (for natural resource gains), and synthetic refineries (for fuel and rubber resource gains).

Diplomacy [edit | edit source]

The gray button with a hand ready to be shaken opens the diplomacy menu. This menu presents a list of nations and a number of filter buttons to narrow down the list.

Interacting with nations through diplomacy.

Filtering can be performed by:

World region
- Africa
- Asia
- Europe
- Middle East
- North America
- Oceania
- South America
Ideology
- Communist
- Democracy
- Fascist
- Non-Aligned (Neutral)
Major Countries
Factions
- Allies
- Axis
- Comintern

After clicking on a nation to interact with, there will be a portrait of its leader, and a little bit of information about what the nation is up to. In the upper right corner of the menu, there will be a couple of tiny flags with arrows indicating the relationship between the two nations.

There are a number of actions that can be taken in the diplomatic menu, provided the requirements are met. 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 the mouse over each option for a description of the diplomatic action and what conditions must be met.

Trade [edit | edit source]

The gray button with box and curved exchange arrows opens the trade menu. There will be a number of tabs and sortable columns listing the major resources available, what is required such as quantity of convoys, and possible trading partners. These possible trading partners can be further filtered by world region, neighbors, or subjects (puppets).

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

Resources are found in certain locations on the map and are not evenly distributed. Almost always it will be necessary to trade for what is needed.

To trade for a resource, click on the name of the country and move the slider to determine how much is being trading for. Resources are typically traded in units of 8. Each trade, unless conducted over land, requires a minimum of 1 convoy vessel plus additional convoys depending on naval distance and total quantity of resources.

Every eight units of a resource imported will also cost a civilian factory, with that productive power going to the nation that is being traded with. Therefore, exports will make a country's industry stronger as civilian factory "power" is pulled from other nations, but a lot of imports will make a country weaker due to the loss of civilian factory "power". However, it may be necessary to import resources to keep the war machine running at optimal efficiency. Tip: trading with puppets gains considerably more than 8 resources per civilian factory traded.

Constructions [edit | edit source]

The gray button with the excavator opens the construction menu. This is where tasks will be assigned to the civilian factories - building infrastructure, new factories, defenses, and so on.

Civilian factories make all the improvements to a State. The number of factories available for construction will depend on the size of the nation, how many factories are being dedicated to providing consumer goods for the country (the Economy Law), and how many factories that are "traded" for strategic resources. The number of civilian factories can be increased by building more, but be careful since each province can only support a certain number of factories. 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.

There are three categories of structure that can be built with civilian factories.

State structures: [edit | edit source]

These constructions improve the state without using up one of the shared building slots. Instead, each type of improvement here has its own level and maximum.

Shared structures: [edit | edit source]

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: [edit | edit source]

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

Production [edit | edit source]

The gray button with the wrench opens the production menu. This is where military factories and dockyards are assigned to build equipment, army vehicles, aircraft and ships. The more factories dedicated to building a specific item, the more will be produced. Infantry, armor and artillery units made will then be assigned to the appropriate military divisions, either for new units being constructed or reinforcement and upgrades for units in the field. Excess equipment is left in the national stockpile. Airplanes produced will be deposited into a reserve pool. Naval units will be automatically placed in the highest level naval base, though one can assign a port or fleet if that would be preferable (recommended for the Soviet Union so they don't end up with all new ships stuck in the Black Sea).

Factory output is dependent on the availability of strategic resources for higher end units, and on the efficiency cap of the nation's industry. New production lines will take time to be perfectly efficient, and if factories are added to a production line, some efficiency will be lost. Factory productivity and efficiency can be improved in the Industrial research tree.

Recruit and deploy [edit | edit source]

The gray button with the tank opens the army planner menu to recruit and deploy units. This is where it is decided what types of divisions are to be trained. These divisions will be filled by the equipment and vehicles built in the production menu. What is required to complete a new unit is shown by hovering over the green progress bars.

The country starts with a few default divisions that can be built. Army experience can be spent 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 it is preferable focus the energy of new tanks or artillery on fresh units, instead of trickling equipment to the field, reinforcement priorities can be set on this screen as well.

Logistics [edit | edit source]

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

Logistics screen [edit | edit source]

The logistics screen provides the general overview of the nation's equipment and resource situation. The center of the screen consists of the equipment, and only shows equipment that is being produced, stockpiled, or used in the nation. The following provides a description of all of the various parts of the screen.

Average production efficiency, which has a above the column, shows the average production efficiency of all the lines of production producing that type of equipment. The yellow bar inside the area represents the average production efficiency for each equipment type.
Equipment type, which says 'Equipment Type' above the column, provides the name and a picture of the equipment that is either being produced, stockpiled, or used in the nation.
Amount produced, which has a wrench being held by a hand above the column, shows how much of that particular equipment is being produced per day.
Status is the green bar next to the amount produced showing how much of the equipment need is being produced. There is also a slider button that lays on the left if the nation is running a surplus of that equipment each day, and on the right if the nation is running a deficit of that equipment each day.
Need, with a hand at the top of the column, is how much of that equipment the nation needs each day.
Balance is the surplus or deficit being ran each day by the country, represented by a scale at the top of the column. If the nation is running a surplus, it will say +Amount , but if it is running a deficit, -Amount .
Stored is the stockpile of the nation. It will be in green with the stockpiled amount if the nation has extra of that equipment, and will show red with the amount missing from the nation, such as the amount needed to reinforce, equip new units, or, for convoys, how much is needed for current trade.
Resources shows the resources that the production line is currently using to produce that equipment. If none of that equipment is being produced, it will not show the resources.

The bottom of the screen includes extra information.

Military factories has a green bar indicating the percentage of the nation's military factories that are currently in use.
Naval dockyards , like military factories to the left of it, shows the percentage of the country's naval dockyards that are in use.
The six icons to the right hand corner show oil, rubber, steel, aluminum, tungsten, and chromium. Next to each icon will be either a green number showing the nation's surplus of that resource, or a red negative number showing that nation's deficit of the resource.

Stockpile screen [edit | edit source]

The stockpile screen is accessed by clicking on any of the equipment on the logistics screen. The graph in the center of the screen shows the change in the stockpile over the previous 30 days, 12 months, or 7 years, each of which have a corresponding button above the graph. The change is represent by a red line, and the X-axis of the graph is the time variable, while the Y-axis is the stockpile variable. Below that is a mini overview of the equipment, which shows the variants of that equipment (i.e. Basic Infantry Equipment vs. Weapons I) and the amount stored of each variant and weekly production of each variant.

Officer Corps [edit | edit source]

The gray button at the top of the screen marked with a hat opens the Officer Corps menu. This menu gives an overall summary of your command power allocation and allows management of military leadership in addition to unlocking military spirits, military doctrines, and preferred tactics.

Controlling the army [edit | edit source]

Main article: Warfare

The player can move their units by selecting them with the left mouse button and then clicking their destination with the right mouse button. If one draws a box around a group of units using left click and drag, all units inside the box can be commanded. One can move troops across the ocean to friendly territory, by sending the units to a province with a naval port and then shift-clicking on a destination port. For an overview of all divisions, including indications of their combat status, click on the Army View icon under the date or press hotkey "o". Right-click on a division's info bar to pan over to it or hold down shift and left click on multiple units to select them all.

Troops are more effective when they are grouped into armies under a commander's command and given plans to execute.

Creating command groups/armies [edit | edit source]

Main article: Commander

The player can create armies of units by selecting a group of them and then clicking on the silhouetted portrait or green plus sign that one will see at the bottom of the screen. Then, go to the selected unit profile in the upper left and click on the silhouetted portrait. This will open up the list of generals to be assigned to armies. There are two types of military leaders – generals and field marshals, both of whom can normally only effectively command 24 units; but some up to 32. Commanders may also have attributes that give them bonuses in certain types of combat situations. If one promotes a general to field marshal, they lose their attributes (except "old guard") as field marshals have different attributes.

Experience and giving orders [edit | edit source]

Countries will gain army experience mostly through combat, but one can start a trickle of early experience by having soldiers "exercise". To do this, select the army group and, in the unit profile in the upper left of the screen, click the exercise button in the upper right of the menu. Be aware that this results in higher equipment attrition, which may not be desirable as a country with limited industrial capacity.

One can spend experience to promote generals and allowing them to lead more troops, or to create and edit new division types in the unit production menu.

An army group can be commanded like any other group of units and simply giving a right-click move order to a destination. However, they will fight better if they are given "battle plans" – a general order that is coordinated along a front, either to advance or defend.

When the player selects an army group, they will see a row of general orders appear at the bottom of their screen. Each of these has rollover text that explains in detail how to use this instruction. This guide will focus on the most important ones.

Naval invasion: Use this for amphibious attacks on enemy territory. (One can move into friendly territory this way, but it is more efficient to simply use port to port movement as described above.)

When one selects naval invasion, one will be asked to left-click on an origin point. This is where the army will gather for the assault. Right click on the enemy province one wants to invade. Note that one will need to have some naval intelligence of every sea lane they will be crossing, so one will have to have warships patrolling or hold naval superiority in those sea areas.

All plans take time, and amphibious invasions take a lot of time to plan. Once the weeks (or months) of preparation are ready, the grey arrow above the army group will turn a faded green. Press that arrow to activate the plan.

Land operations: To make a battle plan for offensive land operations, one must first define one's defensive front – this is the point from which the army group will begin their operations. Select the defensive front button and, on the map, draw a line to indicate where an army group will start. (In many cases, this will be a national border or the current line dividing enemy armies). Then, click the offensive front button (a line with an arrow) and draw the front to where the armies should advance.

The army group units will begin to organize themselves along their defensive front. When they are in place and one is ready to begin, press the green arrow and the units will begin to execute the plan.

One can research doctrines and hire advisors that will reduce the time for a military plan to be prepared or add bonuses to units that are operating with a plan.

Controlling the navy [edit | edit source]

Ships will be automatically grouped into fleets at ports as they are constructed. If one does not like the way fleets are organized, one can drag-and-drop silhouettes of ships from one fleet to another.

Assign commanders to your fleets by clicking on the silhouetted portrait and choosing from available naval commanders. You may recruit new admirals for the fleets. Like generals, admirals may have skills that are assets in particular battle situations or while commanding certain types of vessels. Admirals normally have a maximum amount of 10 fleets to lead.

If a fleet is selected, a row of different orders will appear above it. These range from simple patrol missions to convoy escort duty. Choose a mission for the fleet (submarines, for example, are best used to interrupt convoys), and then right-click on up to three contiguous sea zones, i.e., sea zones that touch each other. This fleet will then carry out that mission over these areas. One can remove these orders by returning the fleet to port and assigning a new mission.

So long as a fleet is operating in a sea zone, enough intelligence should be gathered about that zone to both route supply overseas through that region or to order an amphibious assault across that space, but if the enemy is active in the region, naval superiority is also required.

Controlling the air force [edit | edit source]

Main article: Air warfare

Unlike other units, airplanes that are constructed are sent to a reserves hangar. One can mobilize them by clicking on an air base, then creating an air wing using the button to the upper right of the resultant menu (it has a plus sign). The larger the airfield, the more planes it can efficiently use.

Like naval units, air units operate over regions and are given specific missions relevant to the type of aircraft. Fighters can do air superiority or interception, strategic bombers can target industry or infrastructure, tactical bombers can do close support of land attacks, and so on. To assign an air wing to a region and a mission, click on an air field. This will open the air information map mode.

Left click on an air wing and then right click on the region where it should operate. One can decide what mission it will perform. Planes have limited range depending on their type (strategic bombers have a much greater range than interceptors) and design (dependent on technology researched or experience spent to edit their abilities).

Supply [edit | edit source]

Armies in the field will require supplies to remain in fighting shape. An army out of supply can take no offensive actions at all, including simple movement, even if unopposed. Supply is determined on a territorial basis (i.e., potentially larger than a single State) where each territory is able to support a specific number of troops. However, the final value of this supply to an actual unit is modified by the infrastructure of the State the unit is stationed within. If a territory can support 10 units easily, but if the army is in a province with very low or damaged infrastructure, a supply bottleneck will develop, so not every unit in that army will get what it needs.

Supplies coming over land are also provided by adjacent territories - which forms a supply line back to the capital or an alternate territory if the capital territory is not in one's control. This is why it is particularly important to maintain and defend contiguous States between home and the front lines.

When land paths are unavailable supplies will be transported via sea. Overseas supply is done through convoys and sea ports. Larger ports can funnel more supply across the ocean, though this will also require more convoy ships. For overseas convoys to be most effective, one will need to assign some of one's naval vessels to Escort duty in the regions that they will cross.

The player can check the supply lines and capacities by clicking on the Supply map mode in the menu to the lower right of the main screen.

Special weapons [edit | edit source]

If all three nuclear technologies (Atomic Research , Nuclear Reactor , Nuclear Bombs ) have been unlocked and at least one nuclear reactor has been built, then you will slowly acquire nuclear bombs. To deliver a nuclear bomb the player must use a strategic bomber and have at least 75% air superiority over the strategic air region of the target province. Select the province one wants to attack and press the nuclear strike icon in the lower left of the province information menu. A nuclear bomb will destroy most of the infrastructure and industry of the target and will damage any units in that area.

If one researches both Experimental Rockets and Rocket Engines and also builds a rocket site , then Basic Guided Missiles may be launched at distant States to damage their infrastructure. The main advantage of guided missiles is that they cost zero production and zero resources and do not tie up any military factories. Instead, guided missiles are automatically produced at each rocket launch site at the rate of one every 24 hours. Rocket sites have a maximum capacity of 100 guided missiles which means that the launch site will be totally filled at the end of 101 days assuming no missiles have been launched. Further research into Improved Rocket Engines and Advanced Rocket Engines allows rocket sites to manufacture and launch Improved Guided Missiles and Advanced Guided Missiles respectively. At present it is not possible to launch nuclear bombs using rockets.

Capitulation and winning the war [edit | edit source]

Once a country has lost owned territory above a certain threshold that depends on its war support, it will capitulate. All divisions they own in their core or occupied territory will be disbanded and their core territory will be instantly occupied by the aggressor, but they carry on as a government-in-exile and keep control of their colonies (non-core provinces) - for example, the Netherlands keeps control of the Dutch East Indies. Partisans in occupied territory will continue to be a problem as long as the country's fellow faction members carry on the war - after all, they can still hope for liberation.

If more than one country is fighting on the losing side of the war, the entire faction will surrender when the last major country in it surrenders (you can see which countries are considered majors on the world diplomacy screen). When this happens, the game will pause and a peace conference will begin. The peace conference proceeds in stages based on the war effort expended by the victorious powers. So, for example, if the Allies defeat Germany and the United States achieved the most in the war followed by the United Kingdom, the United States will have the first chance to make demands on the Germans, followed by the United Kingdom. Then, the next most significant victor(s) will make their demands.

This continues until all the victors are satisfied with the peace, all available demands have been made or no nation can afford to make additional demands on the defeated powers.

War demands have a cost, and this cost is deducted from the war score of the victorious nation. Some demands, like making a nation a puppet, require having that as a war goal unless the rules of the nation allow puppeting without a war goal.

Tips to getting started [edit | edit source]

As the player is learning Hearts of Iron IV, remember these important steps as one formulates their plans for world domination.

One will start the game with a few production lines of weapons already active. The most important of these will be one's infantry equipment, so, until more military factories have been built, put most of one's energy here.
When your country is training new divisions, have multiple lines of infantry going at once. If you don't, you will fall behind in army size.
Plan out National focuses early in the game. For instance Germany will want to move quickly along the paths that give it claims on Austria and Czechoslovakia. The USA will need to get itself out of the Great Depression. France has to watch its political stability. Have a long term goal in mind. Keep in mind you don't have to research all the National Focuses one after another. Sometimes it is best to wait a bit for the opportune moment, especially with research boosting focuses.
Each nation has access to extra research slots if they activate specific national focuses. These are easily identified by the beaker icons on the names (though some focuses with that icon give research bonuses instead - read the tooltips for details). The sooner these are unlocked, the better the army will fight.
When researching, try not to rush too far ahead since there are significant penalties to pursuing technology too early in the timeline. However, if one researches computing in the electrical engineering track, one can reduce their total research time by a significant margin.
If a powerful navy is not central to one's war plans, one can usually ignore this aspect of the war and research tree. However, convoys are always useful for trade and supply, so have whatever dockyards owned should focus on that.
If one is at peace, armies should exercise so they can train until they reach regular status and earn experience. Adding an extra regiment, line battalion, or support company to an existing division design is an easy way to beef up one's forces – unless one doesn't have the equipment on hand to reinforce what one has.
In wartime, it is often better to let the new equipment fall into the hands of new units instead of reinforcing and upgrading old ones. Adjust the reinforcement and upgrading of troops with an eye to what one needs now – more active units in the field now or a stronger punch in a few months time.
Democracies should change their economic ideas as soon as they can in order to free up civilian factories that are otherwise dedicated to producing civilian goods.
Don't forget to rest armies after they have reached their objectives. A few days of inaction will help with organization, reinforcement and supply.

Advanced Tips [edit | edit source]

Remember infrastructure and fortifications. Should one be attacked, a line of land forts and a battle plan for a defensive hold along a strategic line (like mountains or a river) could give the player time to hold off an invasion as they wait for help from allies and/or their own reinforcements.
If you lack a resource, but produce it locally (i.e. steel is produced, but not enough of it), try to avoid trading for it unless absolutely necessary. You can research excavation under the industry tab, which will increase the amount of your produced resources by 10% for each tier, up to 50% bonus if all tiers of excavation are researched. This will free up your civilian factories from trade and allow you to construct more buildings.
When there is a lack of material, remember to check what is being produced. It won't do to have too many different recruits going at once (i.e both motorized and infantry) if what the factories are producing is going toward upgrades. An example would be to trim away motorized infantry for a while and focus on just regular infantry. If one lowers the production of motorized and focus that on upgrading an existing unit, the free factories can be moved to infantry equipment and by extension allow for the production of more units.
When Manpower is low, remember to change your conscription law and try attaching Field Hospitals as support companies or disbanding units you don't need, including air wings and ships. If you must maintain a large front and can't afford to reduce the number of divisions you have, you can consider making them smaller. Quite often you can afford to remove one infantry battalion from your default divisions and they will perform almost the same. Keep in mind that the Total Mobilization (Economy Law) gives you -3% recruitable population and generally isn't worth having, unless you can spare the manpower. The Mobile Warfare and Mass Assault Land Doctrines, as well as the Nationalist branch of the general National Focus tech tree give bonuses to your manpower pool. If you have concerns about your manpower in the long run, consider creating high-tech divisions with advanced equipment. Higher production cost is generally linked with manpower preservation - an infantry division will lose a lot more manpower than a mechanized division. Mountaineers and Marines will save you a little bit of manpower, compared to regular infantry, if deployed properly in their respective fields, due to their combat bonuses in mountains/hills and river crossings/naval invasions, as well as their slightly higher breakthrough stat, and they only cost more Infantry Weapons and training time to produce.
Doctrines should be picked carefully and with consideration. It is possible to switch from one doctrine to another, should the need arise, but it takes a long time to research them and you will lose the old doctrine. The good part about doctrines is, that they don't require production and the bonuses come into play as soon as you research them. There are about 10 separate researches in Land Doctrines, 12 in Air, and 15 in Naval. The base cost is 200 days for Land Doctrines/Air Doctrines and 250 days for Naval Doctrines, so it will take considerable time to replace a fully researched doctrine. Use caution should you decide to make drastic changes.
Remember to update, research and produce the next tier of equipment for units you find lacking in quality. Sometimes an upgraded version of a unit has a lot more hidden bonuses than one might expect.
Different Factions have different disadvantages and advantages when it comes to securing resources. The Allies begin with the majority of Rubber production, and anyone going to war with them will have serious troubles with securing rubber without a plan to attack Allied South-east Asia, or without a lot of Refineries. Rubber is needed for all aircraft, as well as motorized/motorized artillery and mechanized. Most of the world's Chromium can be found in the Soviet Union, Turkey, South Africa, France, Cuba and Yugoslavia. Chromium is needed for ships and heavy tanks, as well as modern tanks. The only ships that don't require Chromium are Destroyers I-III, Light Cruisers I-III, Heavy Cruisers I-III, Submarines I-III. If you want to maintain a fleet of capital or modern ships, you will need to secure those places for yourself, or as allies. Aluminium can be found in France, the United States, Hungary, the Soviet Union, and Yugoslavia. Aluminium is needed for all aircraft, as well as support equipment. When planning your strategy you have to plan to either skip mass production of units requiring resources you don't have, or to plan to steal those resources from the enemy to secure your production or deny the enemy production of a particular equipment type. If you are playing as a minor nation, you might want to consider which side to join, if any, depending on the resources you will need to power your economy.
Naval and Air combat seem confusing at first, but with a bit of research and understanding, turn out to be simpler than Land combat. Look up an in-depth guide if you have problems with Air or Naval battles and/or strategy. Have fun

↑ Defines NPolitics BASE_POLITICAL_POWER_INCREASE = 2
↑ ^2.0 ^2.1 from game file \Hearts of Iron IV\common\modifiers\00_static_modifiers.txt
↑ Defines NCountry BASE_MAX_COMMAND_POWER = 200

[1] Defines NPolitics BASE_POLITICAL_POWER_INCREASE = 2

[stability-2] 2.0 ^2.1 from game file \Hearts of Iron IV\common\modifiers\00_static_modifiers.txt

[3] Defines NCountry BASE_MAX_COMMAND_POWER = 200