Essential Hearts of Iron 4 Tips

By Jack Trumbull 25 Nov 2019 2

Hearts of Iron 4 can be unapologetic ally brutal to new wargamers with the sheer amount of systems involved, and especially after several DLCs and patches. Whether it’s figuring out how to structure your forces or what plan of action to take as an Allied state facing imminent doom in 1936, it can be quite a challenge.

Luckily for you, that's where we come in! Now you have a handy guide to aid you in navigating the choppy waters of the second war to end all wars. Make sure you're up to speed with all the latest changes as of the Man the Guns DLC.


Before we talk about the grand strategies that will fuel your world dominating/liberating campaign, it’s important to talk about the cogs in your war-machine. The level of control you have over the makeup of individual divisions and ships can be daunting, but as long as you follow the rules laid out to you, you will be conquering away in no time.

The Army

Arguably the most important part of an HOI4 military, most of the game’s combat mechanics revolve around divisions slugging it out with their evil counterparts on the opposing side. The most distinguishing feature between any two divisions is their makeup in the Division Designer. Here, you can add and subtract different types of battalions from a division, altering its combat stats and overall performance.

Hearts of Iron 4 Tips Army 1

One of the most important considerations to take into account when designing a division is combat width. Each division will take up an amount of space on the battlefield, and having more divisions on a side in a fight will lead to reduced effectiveness, or will block reinforcements from joining the fight altogether. Most battlefields will have “combat width” of 80, meaning that optimal division sizes should be either 20 or 40, if you’re looking to min-max as much as possible (Note: if a province is attacked from multiple directions simultaneously, each new province will add 40 to the total allowed combat width, which means more units will be able to fight at once). Generally, frontline battalions will have a width of 2, the most common exceptions being dedicated anti-air and anti-tank battalions. These both cost 1 width as they’re not considered 'frontline' fighters. Artillery is the other main outlier, costing a heavy 3 width. If you’re approaching your comfortable limit, consider adding a support artillery company rather than an artillery battalion. These 'support' companies don’t bring as much firepower as their larger counterparts, but they add nothing to the total combat width of a division.

On the subject of support companies, two that are almost necessary to include are the engineer company and the recon company. The engineer company increases the amount a division can entrench itself, meaning that given enough time, a single division with an engineering team can become a major problem for an attacking force. Through research, the engineering team will also increase the general attack and defense of the division, particularly in rough terrain, i.e. urban environments, across rivers, forts, etc. The recon company provides simpler benefits: speed and reconnaissance. A division with a recon team will move 10% faster across every terrain type, meaning they can reach the fight faster. This is incredibly important for any division that can expect to fight, but particularly so for divisions that use vehicles. When your division does get into a fight, reconnaissance determines which tactic a side will pick in battle. The higher the reconnaissance value one side has in the fight, the higher the chance their general will pick a favorable or countering pick to the opposing force’s choice.

Hearts of Iron 4 Tips Army 2

There are other considerations to take into account when forming a division, such as what your enemies’ divisions look like, and where you will be fighting them. For example, a division meant to fight tanks in European plains is going to suffer heavily if fighting infantry in African jungles. As such, here are some general tips to keep in mind when building divisions:

  • The more battalions a division has, the more supplies it will need, so “heavier” divisions will frequently suffer attrition in bad terrain. Try using smaller divisions, or adding logistics companies to reduce the negative effects of the environment.
  • All divisions that use trucks, half-tracks, or tanks should invest in a maintenance company. These companies will increase the reliability of the vehicles, meaning less are lost to attrition, and they will also capture a percentage of enemy equipment for you to use.
  • Anti-air companies/ battalions increase your air superiority in a province, but they will only target close air support aircraft, not aircraft with strategic bombing missions (presumably, they fly too high for the anti-air guns to shoot them down).
  • Standard “leg infantry” divisions are the most reliable and cost effective divisions you could hope for. You can build an infantry division to 20 width, add the necessary support companies, and then copy the template so you can alter it to fit your specific needs. Most of your divisions should be infantry divisions.
  • Motorized divisions are faster than mechanized divisions until the third halftrack becomes available, keep this in mind when looking for speed.
  • A division only travels as fast as its slowest part, so it may be wise to pair up a single super heavy tank battalion with an infantry division, as they move at the same speed.
  • A single anti-tank company with the most up-to-date guns can allow most divisions to pierce enemy armor.
  • Infantry has naturally higher organization than tank battalions and support gun battalions. As such, for campaigns that see units being in repeated battles, divisions with a higher ratio of infantry will be able to stay in the front lines longer.

For more information on divisions, I recommend checking out the Hearts of Iron 4 wiki page on the Division Designer & land combat stats.

Editor's Note: Grand (Strategy) Master T.J. Hafer also wrote a Division build guide for us that you can check out, although it's a tad outdated at the moment - part of the reason we decided to launch a new, more comprehensive tips guide for the game.

The Navy

The naval mechanics had a major overhaul recently, so don’t feel alone if you’re confused about what’s new. Ships used to have a similar improvement structure to armored land vehicles and aircraft (which we’ll cover after this section) where a specific ship would be researched, then could be improved by spending experience points. Now hull types rather than whole ships can be researched, as well as the individual modules for ships. Every ship has an amount of slots that can be filled by these modules, but the catch is that ships will take longer to be built with advanced modules and higher amounts of modules overall. There are also restrictions on what ship types can equip certain modules. It doesn’t make much sense to put an aircraft hangar on a submarine, even though you really want to!

There are 5 main types of ship hulls: destroyer, cruiser, heavy, carrier, and submarine. There is a 6th hull type, the super heavy hull, but that only exists as an alteration of the 1936 heavy ship. These ships can vary widely in their roles based on what modules are placed on them, so we’ll go into a breakdown of the general capabilities of specific hull types.

Hearts of Iron 4 Tips Navy 1

Destroyers are light and fast ships that are some of the quickest to produce. They can be outfitted with some modest main guns, but the 2 main uses of destroyers are as torpedo boats and submarine hunters. Due to their speed, a large amount of destroyers can swarm enemy heavy ships and deal heavy damage with torpedoes. These fleets are relatively easy to build due to the short build time of destroyers, and everything but torpedoes can be stripped off the ship to make the build time even quicker, though this will render them ineffective in any other situation. Destroyers can also be outfitted with sonar and depth charges, which is the one way surface vessels can attack submarines. Curiously, due to naval battle AI, submarines will flee almost any battle with depth charge-equipped destroyers, being that the destroyers can actually hurt them. This means that as of the current patch (1.6.2), destroyers may actually function better as convoy raiders than submarines, because destroyers will not automatically flee the second a small enemy force appears (Note: thanks to Rimmy for pointing this out in his HOI4 video!). This will hopefully not be true forever, but keep this in mind for the near future.

Cruisers are the most versatile of the hull types, with the ability to fill almost any role needed. Cruisers can be outfitted with heavy guns and armor, classifying them as heavy cruisers that can perform reasonably well as capital ships. Alternatively, they can have lighter guns mounted with a stronger engine, and they can pursue marauding destroyer packs, or they can have several anti-air batteries bolted to the deck as a means of creating a floating “no-fly zone.” But even though cruisers can cover many different bases, they don’t excel as much as the ship types that are meant to perform in those roles. Cruisers take longer to build than destroyers and aren’t quite as fast, and the heaviest cruiser will most likely lose a prolonged engagement with an enemy battleship. Even so, they can be a multi-tool for any situation, and can be refitted to change their role in the seas.

Heavy ships are the undisputed kings of the sea in the first several years of the game. They have access to the thickest armor and the largest guns out of all ship types, but they are generally slower than other ships, and take longer to build as well. The big guns on battleships are excellent at killing cruisers and other capital ships, but they are less accurate against destroyers. Battleships can trade some of their extra module space for smaller guns specifically meant to target lesser ships, but this lessens the effectiveness of the battleship in its primary role, which is to fight the enemy’s capital ships. Battleships also take a very long time to build compared to smaller ships, meaning that ships you begin construction on will likely be equipped with subpar tech by the time they launch. However, an old battleship is still a battleship, and can be very useful when working with a capable fleet.

Hearts of Iron 4 tips Navy 2

Carriers are very straightforward as far as ships go: their sole purpose is to launch aircraft that will assist in combat. Aircraft are very effective against enemy fleets in large numbers, but a fleet with solid anti-air cover can severely inhibit a carrier’s ability to do its job. Outside of fighting specific anti-carrier fleets, carriers are arguably the strongest ship type in the game for the ability to project air power not only in battle, but in the sea region the carrier is operating in, or even the neighboring land province. Much like battleships, carriers do take a long time to build, but this battleships and some cruisers can make up for this time by performing carrier conversions that slap a flight deck onto these ships after removing the guns. They do not have the same aircraft capacity full carriers do, but they can be sufficient as support carriers. Carriers are vitally important to fleets in HOI4: if you don’t want to build any of your own, you should still plan to specifically target and kill enemy carriers.

Speaking of killing enemy carriers, Submarines excel at hunting down enemy capital ships and shipping. They are also very, very cheap compared to other ships, so a fleet of submarines can quickly be assembled to threaten unprotected enemy ships. However, due to the strange AI behavior mentioned in the destroyer section, submarines are currently cowards, and will flee from battle the second a destroyer appears.  As such, the usefulness of submarines is limited, but a large amount of submarines spread out on shipping lanes will still have an impact on enemy resources and troops.

General tips on building up a navy:

  • Submarines, destroyers, light cruisers, and eventually bombers can lay mines in naval regions if they have minelaying modules. It may be beneficial to build cheap ships that just have minelaying / minesweeping capabilities so you can quickly build up defenses or clear them out as the need arises.
  • Don’t be afraid to launch a ship then immediately send it to be refit with newer technology, the benefit of the newer tech can be worth the wait.
  • Air superiority will impact the effectiveness of naval missions, so provide air cover for your fleets when possible.
  • Build your fleet to counter the enemy fleet. If the enemy is focusing on building mainly capital ships, invest in torpedo technology. If the enemy likes swarms of smaller ships, build ships with many light guns that are more effective against those ships.
  • Research engines early, being faster than the enemy fleet will give your ships a huge advantage.
  • The bigger the ship, the more fuel it consumes. Ships with more advanced engines will use more fuel, so keep that in mind when your fuel is running dry.

The Air Force

The air power part of the combat trifecta is undoubtedly the most abstract, and has less moving parts than either of the other two dimensions. However, it is airpower that can be the determining factor in land or sea battles, so it is important to detail. Aircraft are split into 2 main trees, which I’ll refer to as the “light” and “heavy” trees.

The “light” tree has close air supports (CAS), fighters, and naval bombers. These aircraft are generally more agile and faster than the aircraft in the other tree, but have less heavy armaments and have shorter ranges than the heavy aircraft. These aircraft also have carrier variants that are generally slightly slower than their land-based counterparts, along with further reduced range. Light aircraft are meant to be deployed at the tactical level, or attached to an army so they follow them along the front as support.

Hearts of Iron 4 Tips Air

The “heavy” aircraft consist of the heavy fighter, the tactical bomber, and the strategic bomber. These aircrafts have longer range and stronger armaments than the “light” aircraft, but consume more manpower, and are not as good at targeting specific units. “Heavy” aircraft, due to their range and their intended targets are generally better at the strategic level.

All aircraft can have variants that be upgraded in 4 categories: reliability, range, attack, and engine. Generally when creating a variant of an aircraft, it is beneficial to upgrade the category that the aircraft already is dominant in, in order to increase their strengths. For example, a fighter’s strength comes from its high agility, which both helps them to attempt attacks on enemy aircraft and avoid attacks from the enemy. Upgrading the agility of fighters would give them even more of an advantage over the enemy. However, the other categories do not need to be neglected for the “preferred” category, but every point sunk into an upgrade makes the next one more costly in experience points, so spend carefully!

General air composition tips:

  • Heavy fighters perform better in larger provinces due to their increased range, while regular fighters perform better in smaller regions.
  • Upgrading reliability on aircraft is always a smart move as this will decrease the amount of aircraft lost to accidents.
  • The strategic bomber is relatively expensive compared to the tactical bomber. It may be wise to build more of the less effective tactical bombers for strategic bombing in order to have enough aircraft bombing the enemy’s factories.
  • Heavy fighters are more expensive than regular fighters, but heavy fighters count more towards air supremacy for your side. Consider investing in a more agile heavy fighter to make more use of this effect.
  • If you have multiple air bases in an air region, investing in longer-ranged aircraft is less important so you can rebase the aircraft to where you need them.



The Allies have two options at the beginning of the game. Stall as they did historically, waiting until the Germans swallow up too many other states or declare a direct war on an Allied state, or take the riskier option and seize the initiative, attacking the Germans before they can build up the fearsome army that rolled across Europe.

The first option is the “safer” one in the long run, as the main Allied states, the United Kingdom and France, have strong economies and can build up defenses, fuel refineries, and radar stations before the Germans swing around to confront them. Perhaps the Allies may even get lucky and have the Molotov-Ribbentrop Pact fall apart and see a war between the Axis and ComIntern, allowing even more time to prepare? In any case, the United States cannot be counted out, and the Allies should do everything in their power to encourage the United States to join the war as quickly as possible. The US has such vast amounts of manpower and natural resources that they can easily turn the tide of the war.

However, the Germans are decidedly weaker early on, and with a combined effort from the UK and France, may prove to be an easy target. It is important to note that the UK does not have a huge military in 1936, and will likely play a support role to France’s army. Italy should also not be counted out, as they have a decently sized and experienced army, fresh out of the conflict in Ethiopia. Those forces can prove to be a major distraction if left alone to run rampant around Africa, where both France and the UK have many important colonies.


The UK needs to decide whether to abandon the continent and focus on the navy to keep Germans at bay, or to put more resources into the army and potentially risk a weaker navy, opening the isles to attack. There’s not much getting around this quandary, because the United Kingdom has a relatively sizable amount of factories in 1936, but they have not sufficiently re-militarized since World War 1 to call them truly powerful. If the British go for a continental intervention, they can bottle the German navy up in the Baltic Sea if they manage to take the German land adjacent to the North Sea. This can negate the danger the German navy poses to the isles, and will prevent a sudden invasion.

However, this gamble may not work against the Germans, who can be formidable even at their weakest. It may be beneficial to focus on growing the home industry rather than focusing directly on the military in order to give a better long-term advantage. If a more defensive strategy is planned, the UK should take this time to work on building sea forts, AA guns, and radar stations. The British Isles have been historically difficult to conquer for a reason; you can use that to your advantage!

Suggested pre-war strategies:

  • Build many civilian factories early, you will need them for the various defenses you’ll be building on the home islands.
  • Research air technology to help defend the infrastructure of the UK (and France too if you’re feeling generous); better fighters and radar helped win the Battle of Britain historically, it can work in HOI4 too!
  • The UK is not known for having great amounts of manpower, consider a land doctrine that takes this into account.
  • The UK can call upon its several Dominions to help during wartime, make sure to make use of your colonies’ manpower!

1B. France

France starts in 1936 with one of the largest land armies in the world, rivaled only by the USSR and Japan. Should France decide to do so, they can build up their forces and present a very challenging foe to the Germans. The Italians cannot be counted out though, and France will end up fighting a two-front war. Fortunately for the French, they have many natural barriers in place to help block the advance of their enemies. The French should focus their efforts on making the homeland as impregnable as possible, building forts along the border with Germany and Italy, as well as with Belgium (the Germans pulled the same “let’s go around them!” trick twice in the 20th century, make sure you keep an eye on Germans approaching from the north!).

Hoi4 tips france

Unfortunately, the French have several important colonies scattered around the world that need defending as well. If the military industry is prioritized at the beginning of the game however, a decent stockpile of equipment can be built up before these resources are threatened. The most important part of France is France itself, and should be defended at all costs.

  • France has plenty of manpower early on, but is lacking in industry. Focus on factories to remain competitive.
  • France starts with 53 divisions in France itself, make sure these divisions get trained and are stationed on the borders. They can overwhelm the Germans if timed properly!
  • A Mediterranean fleet will help keep the Italians pinned down in the Alps as your forces take care of the Germans in the north. Even though Germany and Italy are France’s neighbors, fighting them on the sea is still important.


The United States has easily the most dominant industry in 1936. However, presenting a problem to the rest of the Allies, they are isolated and not a member of the Allies faction. During the period of time before the US can convince its citizens to allow it to fight, the US can provide much needed fuel and equipment to the Allies and the USSR.

Unlike the other major states in the Allies, Japan will play a serious threat to US interests in the Pacific. The US will need to build a sizable fleet to deal with the Japanese, and will need to deal with a 2-front war. Unlike any other state in the game however, the US has unparalleled natural resources and manpower, and can be the strongest state in the game.

  • The US can afford to build divisions that sap more manpower because of the reserves they have, use this to your advantage.
  • The US will not enter the war immediately, as such, they have more time to build equipment, build factories, and build ships. The US can enter the war in a position of strength.
  • Fighting the Japanese in the Pacific can be very difficult without marines. Make use of their naval invasion bonuses to seize islands with airfields so you can bomb the next set of islands.
  • Invading Europe through Africa may prove easier than landing in Normandy. After attacking Italy, another naval invasion in the south of France will be relatively simple to set up.


The USSR is the only major state in ComIntern in 1936. The USSR has a great amount of manpower and natural resources, second only to the United States, but is held back by early internal conflicts. The USSR can see a civil war before World War 2 proper breaks out, and will need to be prepared to defend itself against the rebels.

This isn’t even mentioning the main threat to the USSR, Germany. The Germans are capable of getting a large mechanized force quickly, and will spell trouble for the USSR in the early game. Much like Germany, the USSR is in a weaker state closer to the start, so preparations to increase the strength of the military should be an early priority to avoid presenting a welcoming target for the Germans. The Japanese may also be interested in taking a bite out of the eastern part of the USSR, and defenses should be built up in case the Japanese decide that China alone isn’t enough for them (Note: China is never enough for the Japanese).

hoi 4 tips random

The USSR’s strategy before a world war breaks out should focus on two key areas. The first area is to further build up the industry of the USSR so that troops will be properly equipped when the war kicks off, and the other area is supporting Communist allies wherever possible. The USSR stands largely alone in 1936, with its only allies being Mongolia and Tannu Tuva. Neither of these states can offer much in the way of direct military support or through lend lease, and additional support is necessary if you’re looking to establish ComIntern as the new world order. The USSR should secure as many Communist allies as possible so that it will not stand alone against the Axis or Allies when the time comes.

  • Communist China is a next-door Communist neighbor that can prove a useful distraction against the Japanese, or even a helpful ally against the Germans if the war in China goes well. Support them as much as possible without getting directly involved by way of lend lease.
  • Station troops prior to the war in cold areas as much as possible. This will acclimate them to the extreme cold weather they will face in combat, and reduce the penalties they take.
  • Many states around the world have large blocks of Communist support, even if they are not fully Communist. Use Political Power to pressure these states into becoming Communist, then invite them to ComIntern.


The Axis in 1936 is just Germany, but will typically invite Italy and other small European powers in within the next few years. The main problem facing the Axis is that they are wedged between the two other main factions. The Allies in Western Europe are watching the aggressive actions of Germany and Italy closely, and will likely intervene should the Axis go “too far.” To the east, the USSR will be looking to expand Communist influence further into Europe, and will gladly take opportunities to go to war with the Axis.

Both Germany and Italy have several options to take in terms of annexing small European states, but doing so may trigger the wrath of the Allies.  It may be best to focus efforts on fighting the USSR rather than the Allies, as the USSR will be the larger challenge early on. With this in mind however, the UK and the US both have focuses that will target Germany, so the clock is ticking, regardless of the path the Axis decides to take.


Germany begins in a highly precarious position in 1936. The Wehrmacht is strong but not almighty, and there are eyes watching what happens in Central Europe closely. Growing too quickly and being too greedy can bring down the wrath of the British and French, who are both relatively stronger than Germany in 1936. However, annexing the neighboring territories will supply Germany with much needed manpower and natural resources. Germany should also look for oil sources early, as their sources will be lost quickly during wartime, and their convoys will be harassed by British fleets.

hoi4 tips germany

Germany has a strong industry and can easily build up a mechanized military. It is important, however, to not neglect the defenses around Germany, as any war it fights can easily become a multi-front war. Layers of forts and AA guns will reduce the damage done by outside forces, and free up precious manpower for offensives.

Germany has multiple areas it can annex pre-war: Austria, Czechoslovakia, parts of Yugoslavia, and Poland. The initial Anschluss is a relatively safe option, but the more land Germany takes, the more likely the victim of the annexation will fight back, and that the Allies will intervene to protect the annexee. Be patient, but remember, you’re on the clock, with the USSR all too eager to roll right into Europe.

  • It will be difficult for Germany to build a fleet to stand up to the British directly. Look into building submarines and naval bombers to even the odds for your surface vessels.
  • Refineries will be key as Germany will need oil for their vehicles, but will not produce enough naturally once the war starts. Be sure to build up a big stockpile, you will need it.
  • Try to fight one enemy at a time. Germany can become quite powerful by 1939, but they did end up losing the two-front war they fought historically.


Italy starts off in war against Ethiopia in 1936, which is a unique situation. The war is not a difficult one to win, considering Italy’s much larger military, but crossing the mountains will prove time-consuming and fights against Ethiopian defenders can drain manpower if you’re not careful. After defeating Ethiopia, a few imperial options exist for a historic Italy. Yugoslavia can either be befriended or claims on Slovenia and Dalmatia can be pressed against them. Additionally, Albania can be occupied, extending Italian control well down both sides of the Adriatic Sea. However, much like Germany’s annexations, aggressive actions can draw the ire of the Allies, so an expansionist Italy should be prepared to fight to defend these conquests.

A strong fleet is necessary to Italy’s survival once war begins as most of Italy’s oil sources are located in Libya. A Mediterranean fleet can ferry troops back and forth from Italy to Africa, as well as halting direct invasions from Africa. Outside of the difficult option of attacking over the Alps in Western Italy, the only viable invasion option for the Allies will be from African bases. Should Italy manage to seize the Suez Canal and the Straits of Gibraltar, invasion will be almost impossible.

One of Italy’s largest weaknesses is the lack of a strong industry in 1936. The player should focus on building more factories to allow for quicker construction in Italy’s conquests, as well as preparing defenses along the French-Italian border. It’s also advisable to build up a large stockpile of fuel, because British and French troops in Africa may be able to cut off Italian access to oil.

  • Lighter divisions can go a long way in Africa. Most divisions will suffer heavy attrition penalties when fighting in the desert, so consider building divisions with low supply cost.
  • The Suez Canal can be destroyed after being captured. To prevent reinforcements coming from further east, a mission to seize and destroy the canal may offer some breathing room to Italian forces in Africa.
  • Greece is a potential war target as well, but their mountains make it a difficult country to attack. If you really must attack Greece, bring lots of mountaineers.


Japan needs oil. Japan really needs oil. The 1936 start sees Japan with one of the largest navies in the world, a sizable air force, and a relatively mechanized army, but not nearly enough fuel to support these forces for long. There are several options for expanding into the South Pacific to seize oil sources, but this will quickly bring Japan to conflict with the Allies. Japan must act quickly and decisively in order to ensure their military continues getting fuel.

hoi4 tips japan

China presents a major opportunity for the Japanese, as you can play the Chinese warlords against each other for land, but when pushed too hard, they may join together to fight you off. It’s important to form a balanced expansion that will not quickly turn the Chinese against you, but going too slow will allow them to unify on their own anyway. In either case, China will be where most of Japan’s forces will see action for the first few years of the game, and may be the main battleground for Japan in general. If possible, seek to eliminate major Chinese states before antagonizing any other states, particularly the United States.

The United States has a much higher industrial potential than Japan, and will in all likelihood attack by the early 1940’s, whether provoked or not. The Japanese need their navy to act as a shield against the Americans. Striking early will bring the Americans into the war sooner, but it will also put a likely inferior American navy against a modernized Japanese navy.

  • Use light infantry divisions with engineers for defending the various islands. Marines get most of their benefits when attacking, so if you’re going to be on the defensive, don’t waste your marines on a non-critical island.
  • The Japanese navy won’t see too much action before the Americans enter the war, but it is very important to have the strongest navy possible to prevent the Americans crippling Japanese operations in the Pacific.
  • When building planes, remember that most of their operations will take place over large ocean territories. Upgrade their range when you can to make their sorties more efficient.


Congratulations! You’re a target for the larger factions. Your main goal during the prewar period should be seeking out the faction that’s most likely to win (or at least help you survive) and doing what you can to gain their approval. That way, when you inevitably draw the ire of the bullies on the block, you have allies that at the very least can be a distraction to the enemy.

hoi4 tips unaligned

General strategy should revolve around building heavy forts on borders and doing what you can to increase natural resource production through the excavation research in the industry tech tree, and through building refineries. States are more likely to look favorably on you if they’re trading with you. The other benefit of expanded industry will be the ability to quickly convert civilian factories into military factories to churn out weapons (for you or a lend-lease ally) as soon as things start to look sour.

  • Most unaligned states (Chinese states excluded) will frequently have lower manpower than the major states. Keep this in mind when selecting land doctrines. If you aren’t able to get a large mechanized military, the Grand Battleplan doctrine gives an entrenchment bonus, perfect for waiting out a long war.
  • At the very least, build fighters to defend your forces and factories from above. Losing air superiority can be devastating to ground forces, and having your factories bombed can cut off critical supplies.
  • Hire a political advisor that will guide your state in the direction of the faction you wish to ally with. Becoming that ideology will make that faction friendlier to you, and more likely to offer you protection.


With historical focuses turned off, things can very quickly become crazy for everyone on the map. The UK may decide to become fascist, America could fight a second civil war over civil rights, and Trotsky could end up leading a Communist Mexico. Nothing is guaranteed now without the guiding hand of history there to smooth everything out, and so the main goal for a player without the benefit of hindsight is to join or form a faction and make friends with resources.

hoi 4 tips random 2

The main states to watch out for are the ones who have gotten alternate history focus trees. This will make them unpredictable allies. You can more frequently depend on states who are using focus trees from launch, as there are less alternate history options there. Additionally, states with generic focus trees are more likely to act unpredictably, but they will generally stay neutral as usual. Make these neutral states your allies when possible, to ensure you have a (relatively) trustworthy friend at your side when the going gets tough.

  • Autarky! Becoming self-sufficient means that you won’t have to rely on a potential future enemy for resources. Either build refineries to grow your own stockpile, or make friends with some generic focus tree states who are less likely to stab you in the back by suddenly becoming Fascist.
  • Be prepared to fight in unexpected places. Many ahistorical campaigns will see fighting in South America, a place World War 2 never reached. Build divisions prepared to fight in specialized locations, as generalized divisions will perform worse than one made to fight in the jungle/the desert/ etc.
  • Keep an eye on your focus tree. Some trees depend on another state choosing their historical path in order to work. You can’t become Democratic best friends with the United States if they’re Fascist! Either speed through these focuses as quickly as possible, or choose the self-sufficient options to eliminate external factors.

What other guidance would you like to see? Let us know your top Hearts of Iron 4 tips in the comments!



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