Hearts of Iron IV, review of.

Hearts of Iron IV is like a phoenix rising into a new era. As cliche and perhaps cringe-worthy as the analogy can be bear with me as I declare that it is an appropriate and evocative representation of what the game is and where it is coming from. It is a whole new entity, billowing fresh ideas and approaches into a strategy game setting that so desperately needs it. It is rising from the ashes of its predecessors who are obtuse, demand hard numbers and are sticklers for historical accuracy… and they still seem to have an influence, which in and of itself is not a bad thing.

The game provides the opportunity to be an active participant in the largest war known to man. And, dadgum, is it exciting to be apart of. Despite running its course during the relatively small time frame of 1936-1948, it is likewise surprising just how involved preparing for war can be.

Built from the ground up, Hearts of Iron IV implements some interesting design elements using mechanics that are already familiar in war strategy games. Some work elegantly to give the player some elbow room to work. Others are a little harder to conceptualize or even seem to work against the player. This type of conflict in the mechanics, this uneven approach to numbers, seems to thread itself throughout all of the game as it tries to define itself, trying to decide whether it is a WW2 simulation like its forebearers or a sandbox grand strategy based in the WW2 era.

The research trees provide advancement in highly effective military doctrine, upgrades to units, and increased industrial efficiency. The time needed to complete research varies and can be shortened in many ways. Conversely, penalties to completion time are applied whenever you strive to research beyond the yearly timeframe. All of this is nothing new to strategy games.

Hearts of Iron 4 provides an additional research-like function that aims to orient the grand designs for your nation: National Focus. Constructed similarly to the research trees, though far more elegant and involved, National Focus is a central step-by-step plan to easing your nation’s progress to color history.

It is what makes your nation, and every other nation on the map, one massive variable to the writ of history. While there is a ‘generic’ National Focus tree for most of the nations, which is admittedly quite underwhelming, the eight major powers have their own specific trees, particular to their place and status in 1936. The possibilities here can be quite compelling:

Germany sets out to reclaim what of theirs was lost… and then some. The Soviet Union is playing catchup, exactly how this is accomplished and who this exploits is a giant question mark. Italy is striving to extend beyond the center of the earth, which direction they go is uncertain. France is the wild card possessing the weight needed to sway global ideology. USA is isolated and recovering from an economic depression and must decided which cause to put its abundance of resources. The UK has much to consider with its global empire, which, if not handled properly, may very well be the nation’s downfall. Finally, Japan may turn its focus inward to find a spiritual center and decide which military aspect to preemptively thrust forth.

Example of the Italy national focus tree.

Example of the Italy national focus tree.

Progressing through the National Focus tree is not required. But each focus is a tremendous asset to your campaign; omitting them from your strategy will only do you harm.

At this point I would be remiss if I do not declare the following: The National Focus trees do not railroad your campaign. They are constructed in a way that is flexible but still involve careful consideration and outlook. Becoming familiar with the layout of these trees, especially for the major nations, is critical in your approach to each and every history-smearing campaign you play.

Hearts of Iron 4 certainly provides the outlook and opportunity with the national foci. The real work comes with logistically making these crazy plans a reality. Sure, you have armed forces to do the talking for you. But getting boots onto the field and planes into the sky is half the challenge. In part because of some of the game’s rather particular and, if anything, shaky design choices when it comes to infrastructure.

You have no national treasury, there are no tax sliders to futz with. Your currency does not come in yen, pounds or dollars. Your nation’s war machine is funded by natural resources, supplies made from these resources, military experience, and political power used to boost your own infrastructure through very effective advisors or to exert your influence on other nations.

Concerning industry and production, there a few conceptual hurdles that a new player will have to overcome – Strange blips of logic that, in a sim-like game, either overlook hard, real numbers or deprive you of strategic opportunities.

The first example is how the game handles trading. Chances are well enough that your nation will not have sufficient of the game’s six natural resources in order for your production lines to run optimally. To overcome this shortage you can set up a trade with a nation that produces the desired resource. For the cost of one factory/8 units of a resource, you can then acquire what you need. This ratio cannot be adjusted.

The problem comes from the fact that the quantity of these resources are not logically assigned. In a game where divisions of troops are numbered in the tens-of-thousands, naval units have a water displacement rating, and defensive bunkers take two weeks and three days to build, it is curious that, for example, Denmark has ten aluminum. Ten… tons? Ten… extraction points? Ten… of what exactly? What is the quantifier here? Ten, let’s just stick with ‘units’, I suppose. This is a figure that is just kind of assigned to your nation…

And this is not some asinine, nitpicky observation. Because these numbers are so finite, they are that much more precious. But short of a ‘closed economy’ trade law, which no nation I have played begins with, there is nothing stopping any other nation from brokering a trade deal with you. Making matters worse, you have zero say in how much of what goes to whom. To say this is a setback would be an understatement.

Currently, the trading system is a type of automation that, playing as a major nation or not, simply doesn’t fly with me. A nation’s factories are critical and should not be flung around all willy-nilly like. Likewise, trade deals could be much more engaging if diplomacy were more directly involved. And if the quantities of resources were more ‘real’ you could broker bulk deals or trade resources for equipment and armaments.

The design for production lines is logical and rather elegant. Each production line uses the natural resources on hand to manufacture its assigned product. The longer one line produces, say, tactical bombers the more efficient that that line becomes at producing them. When you complete the research for an upgrade to that particular tactical bomber you can assign it to that production line at a fraction of an efficiency stab. If you begin that upgraded model in a new line or swap it out with another production line the efficiency stab will be far greater when compared to the aforementioned production line. The process is streamlined and intuitive. This is another successful design example that Paradox uses to encourage thoughtful, deliberate planning – planning which can include creating variants of gear that has already been researched! Waste not. Want not.

Example of starting USA production lines

Example of starting USA production lines

On the other hand, there is a massive design oversight concerning what happens with the products after they roll off the production lines: Your national storage.

Firstly, let it be known that you do not stockpile natural resources. Any excess resource not plugged into your production lines are essentially wasted.

Stockpiling occurs when products, such as infantry equipment, roll off of your production lines. If your fielded troops are already armed, the infantry equipment are then stashed into your national stockpile. Unlike natural resources, the stockpile deals in much bigger and more realistic numbers. Stockpiles can be in the green by so much as tens-of-thousands in supplies, planes, tanks, et al.

The next logical line of inquiry can be as such: Where is the stockpile? What physical location on the map houses all this precious surplus gear? Where are my enemy’s stockpiles? The answer: It doesn’t exist.

Any surplus gear is magically stored in the aether, it only exists as a number – much in the same as the natural resources. A surplus in stockpile will materialize only when upgrades are needed in the production lines or reinforcements are called upon. This almost seems like an exploit, a gross oversight. In a game where you can assign planes to bomb factories and dockyards – hampering your enemy’s war machine – what logic is there in not being able to scout out your enemy’s cache and target it?

This strange intermingling of elegance in design with plodding automation and gratuitous oversights seems to be the result of Paradox continuing in the effort to ease micromanagement involved in a grand campaign. It is a work in progress.

Luckily, once we move past the infrastructure and begin composing and commanding martial forces, we see what makes Hearts of Iron 4 really shine.

In order to realise any of the plans you make, any radical, world-inverting idea you may have, your nation needs a military. Comprised of Air, Naval and Land units your military is the muscle of your nation. Each branch has its own distinct units with their own uses as well as an experience counter whose function we’ll get to in a moment. Paradox is not looking to reinvent the wheel with these units: Infantry is your meat shield; Engineers entrench; Tanks blow up tanks; Bombers drop bombs on stuff… except national armament caches.

Unlike training and deploying individual land units in other strategy games, HoI4 provides you with its Division Designer. The idea here is to eliminate another element of micromanagement that so often plagues strategy games. Indeed. Instead of training a single battalion and having them appear on the map, you instead spend accrued army experience and assign them into a division template along with other battalions. The compositions created in the Division Designer are saved and are then ready for training and supplying whenever you deem necessary. You can have any number of Division templates saved.


The Division Designer is a pretty great idea, and one that is implemented very well. The game does a great job of breaking down the makeup and equipment cost of each division, making it easier to spot deficiencies, which is a boon because there are a lot of stats associated with a even a single division. From here you can also manage which divisions have dibs on upgraded gear. The grid also helps in visualizing the composition of each division – admittedly making it easier overstuff the divisions and therefore overtaxing the supplies needed to equip them. Due to its connectivity with your production lines, the division designer is an effective central location to manage the deployment of your land forces.

Once on the map, you can select any number of divisions and assign them as an army. You then give these respective armies a leader who possesses attributes that, ideally, complement the divisions’ composition. It is possible to manually control each division within an army, to place them at the front line or advance them into enemy territory. Or, you can use Hearts of Iron 4’s built-in Battleplan system.

Another mechanic built from the ground up, The Battleplan is a plan of engagement (or tactical retreat!) that you literally draw onto the map. Each army comes equipped with a toolbox for drawing such plans. As a simple example, let’s say that as Germany you plan on storming into Poland in six months and are waiting for supplies to reach your troops.

Now would be a good time to draw up your battleplan. With an army selected you create a front line, most commonly on national borders. Looking deep into enemy territory you draw an offensive line that the divisions will push their way to. Automatically, the divisions will toe the line and await your signal to advance. The longer a battleplan is in place before initiation, the greater the attack bonus the army receives. And when you make the call the AI will then make the best effort in slogging its way to the offensive line.

Your battleplan toolbox

Your battleplan toolbox

… And it works. The AI actually does an admirable job of handling your divisions on the fly. Even in a nation with varied terrain, it will for example, keep your infantry out of the mountains and your mountaineers out of the plains. During heavily-contested advances the AI will keep divisions behind in claimed territory to act as a temporary garrison, since the game has no ‘besieging phase’. Divisions will retreat automatically. They will rejoin the fray when rested and resupplied.

Sometimes you need to make manual tweaks to division positioning, especially because drawing a battleplan in tight spaces can get a little cumbersome and, frankly, kind of messy. My battleplan into Greece when playing as Bulgaria looked like a jumbled mish mash. However, in a grand campaign as a major power, with multiple fronts to handle, multiple swaths of territory to manage, the Battleplan system is a wonderful easement to your command, especially during the peak of the War, which is truly a sight to behold and thrill to be apart of.

Overall, before your severe knee-jerk reaction to AI-handled military shatters your incisors, know that the success of an offensive battleplan is largely dependant on the makeup of the participating divisions. The AI has no part in your Division Designer. Sending an army of ill-equipped puissants into your battleplan will certainly turn them into gore soup. Plan ahead. Plan accordingly.


As it stands currently, land forces have an elegant and involved method of creation and management. Navy and Air forces conversely, have a kind of set-it-and-forget it feel.

After aircraft roll off the production line, you assign them to pre-set air zones. Within the air zone you assign certain missions based on the planes’ capabilities, i.e. Fight other planes, bomb boats, provide ground support. After that, they just kind of hang out in the air base or naval carrier until war begins when they can fulfill these missions. The player has zero (0) control over the planes other than stationing them, though you can automate at which period during the game’s day/night cycle that the missions should be carried out. I’d like to see more opportunities to use aircraft outside of war. Recon, primarily would be pretty awesome.

Naval forces are likewise just a list of ships broken down into player-assigned fleets that sit in port or naval zones until war breaks out. Fleets are given orders the same way air wings do: Select a mission such as trade disruption, convoy escort, search and destroy. Then pick a naval zone. Then wait… I guess. Unlike air wings, you can directly control fleets and engage them in naval battles. Oftentimes Naval and Air units will clash on the high seas, which is an awesome spectacle to consider and visualize in your mind’s eye.

I had higher expectations for the naval game. Similar to aircraft, I’d like to see more from my naval units outside of war. They especially can be a way of accomplishing aggressive, opportunistic goals while subverting the world tension mechanic.

Yes. Let us speak of World Tension.

Closely tied to the game’s factions and their ideologies, world tension is the barometer of war. I like this idea and believe that it can be utilized and exploited to a greater degree. At 0% world tension, the world is pretty quiet, ideologies pricking at the hearts of nations. At 100% world tension, factions have been created, sides have been picked, stakes have been pulled – the world is on fire. How the world gets from 0% to 100%, and how quickly, depends primarily on the interactions between nations.

A breakdown of the jerks responsible for Armageddon.

A breakdown of the jerks responsible for Armageddon.

Costing accrued political power, certain diplomatic actions bump up the tension in varying degrees. Rushing to become fascist will eke it up by a fraction of a percent. Declaring war on a minor nation will have a greater effect; Joining the Axis faction even more so. Declaring war on a major nation as the Axis coalition causes a spike in tension and will freak out the Allies which in turn will trigger a retaliation which kicks up the tension even further and onto the point of no return.

… And this is just one international scenario out of countless others. This is an effort that Paradox seems to be taking in making Hearts of Iron 4 less of a WW2 sim and more of a sandbox based on the WW2 era.

The game provides opportunities for all nations, even the majors, to shift out of their historical ideologies. USA can go communist. France can go fascist. At this point, though, being in the allies doesn’t seem nearly as fun – something that I hope will be addressed in later DLC, perhaps? Picking a faction is just as important as designing the correct type of division. It largely determines your involvement in the war.

Nations do not ally nations; Factions ally factions. I do not bemoan this. Ideology is a legitimate determiner of world war in either initiating it or striving to prevent or end it. Ideology is what hardens a people, unifying them, making them more difficult to defeat – one of the reasons atomic weapons are available for research!

This is where I think a little more effort could have gone into deepening the diplomacy game. Because my mind keeps going to the small nations. The ones with the generic focus tree. The ones who begin the 1936 campaign most likely unaffiliated in ideology and, therefore, faction. The ones with only two or three templates in the division designer. The ones with a completely inadequate navy. If the diplomacy game were stronger, if the game were more willing to go off the beaten path, these nations too would have a fighting chance in coloring history.

The blue piece of the ideological pie means that a democratic Germany is all too possible!

The blue piece of the ideological pie means that a democratic Germany is all too possible!

HoI4 does in fact give you the opportunity to create your own faction. This is made available even to the non-major nations. But this course of action does very little in the grand-scheme of things. Sure, you created the legionaries fascists of Guatemala. Unless you’ve managed to seed this ideology anywhere else in the world or even just in your region, by 1939 nobody will want to join and your nation will be just a pimple on the geopolitical map.

Indeed. You may fly off the rails of history but chances are the AI won’t, which then severely inhibits your own national exploits all the more. Not without more diplomatic, or even duplicitous, options for the player, or an earlier start date – even if it is just a single year – will we see anything resembling the sandbox Hearts of Iron 4 feels like it wants to be.

At the foundation, the game seems to be conflicted with itself as if in a state of flux. And that confusion translates into how it works for the player.

There are two starting dates available: 1936 and 1939. Choosing 1939 places you closer to the throes of war. Choosing 1936 gives you more time to make your preparations, to contemplate your grand history-smearing designs. The problem with the earlier start date is that there seems to be quite a bit of faffing about, when there really shouldn’t be – as I hope I’ve been able to express thus far in this review. There really only seems to be two modes in Hearts of Iron 4: Wait for war; Fight the war.

Despite some of the underdeveloped and confusing aspects of preparing your nation for war, the thrill of thrusting your nation into the international fray is still worthy of critical praise.

There is an undeniable sense of anticipation and/or anxiety as the world tension cranks upwards, often snowballing to 100% – Even more satisfying if you are the one causing it to spike, catching your enemies totally unprepared for world war. There is a rush of excitement when you witness the realization of your battle plans as the AI-run armies push your meticulously designed divisions forward to their objectives on their respective fronts; and just as horrifying when you witness them fallback and get chewed to bits after a successful counter-attack. The relief you feel when friendly faction reinforcements arrive… the trail of icons denoting victorious naval battles… notifications of destroyed ports… the roar of airwings battling for superiority punctuated by the rata-tat-tat of automatic fire… It is all happening right there on the map. The battle plans, the animations, the sounds – for the first time a Paradox map truly feels alive! And I’m glad to be apart of it.

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