This is the twentieth in a series of reviews of Paradox’s empire management games. See the earlier reviews here:
Europa Universalis II: A Tale of Two Europas
Hearts of Iron: Europa of Iron
Victoria: Nineteenth Century Essay
Crusader Kings: A Dynastic Adventure
Hearts of Iron II: Return Engagement
Europa Universalis III: A Whole New World
Europa Universalis: Rome: Make a Desert and Call it a Game
Hearts of Iron III: One Plus Two Equals Three
EU III: Heir to the Throne: Not Done Yet
Victoria II: Same But Different
EU III: Divine Wind: Winds of Change
Sengoku: Shogun: Only War
V II: A House Divided: Limited Expansion
Crusader Kings II: The Second Crusade
HoI III: Their Finest Hour: A Final Polish
March of the Eagles: A Minor EU
V II: Heart of Darkness: Darkest Victoria
Europa Universalis IV: A Fantastic Point of View
Stellaris: Paradox Among the Stars

On January 23, 2014, Paradox announced that it was working on a fourth Hearts of Iron game, which would bring the series to the Clausewitz 2.0 engine introduced with Crusader Kings II, and, presumably, a more centralized set of mechanics, as seen in Europa Universalis IV.

Development took longer than normal, and the game was not released until June 6, 2016, a month after Stellaris, a game that was not even announced until a year and a half after the announcement of HoI IV. While HoI had traditionally been the big money-maker for Paradox, HoI IV has not generated anywhere near the same number of patches and expansions as Paradox’s three immediately preceding games. This review is specifically looks at the game as of patch 1.2.1, released on September 23rd, before the first expansion.

Overall, the game is similar to the previous entries in the series—a pausable real-time empire-management simulation. Thanks to the tight focus on on about a decade (1936-48) this means that you see hours go by and production and many tasks are evaluated by day (combat and movement is hourly). It is the most “wargamey” of their titles, but as a grand strategy game, combat happens without further input from the player, who is concerned with general orders, diplomacy, and development.


Production in the earlier games had you producing entire divisions at a time, and/or complete air wings. Now, it switched to directly producing equipment. So instead of ordering up an armor division, and the appropriate tanks get produced, you assign an armor division to be formed, and it receives the tanks you have on hand. Or it sits as a ‘theoretical’ formation waiting for appropriate equipment to be produced. This also means that new equipment slowly trickles out to units in the field as it produced, instead of an entire unit upgrading all at once, as in previous games.

Even the basic equipment needed by infantrymen needs to be produced before they can head out. This is largely abstracted, but there are improvements (which need researching) over time. Factories are assigned to each type of production, and each one adds to an overall averaged total. Each production line has a production efficiency that starts low, and builds up over time, representing tooling time and economies of scale. At the start of the game, maximum efficiency is 50% (and a new production line typically starts at 20%), but this also goes up with further research.

A UI element that was lost on me for a while is that the icons of any technology that results in a new type of equipment to produce is given a larger icon than the ones that unlock an ability or extra bonuses. Thinking about it, I think they missed some opportunities here. Infantry equipment comes in four types, with a couple in-between bonuses, and sub-branches for things like anti-tank weapons, and artillery has similar sub-types. I wish there was more of this around other major equipment types.

Factories are divided between military and civilian, with only the military ones producing equipment. Civilian factories are needed to produce abstracted consumer goods, which takes them out of the production pool, and they also behind-the-scenes are used to create materials to pay for resources that you need to import (the list of raw materials is essentially unchanged from III), and if another nation imports some of your resources, you get to use their civilian factory. Remaining civilian factories are used to construct new on-map facilities, including new factories, infrastructure, RADAR stations, fortifications, and the like.

As war approaches, or is declared, you can pass more ambitious draft laws, and you need fewer factories devoted to consumer goods. Instead of all that capacity simply helping build your internal infrastructure, you can convert factories from one type to the other; this takes time of course. Also, there are naval dockyards, which are factories that only produce ships, though they, somewhat strangely, do not use the efficiency system at all; switch a dockyard from a battleship to a submarine, it’s all the same.

This is one of the main elements to HoI IV as a game, and its best feature. No other WWII game has really presented all the various elements that go into the industrial might that determined much of the character of the war. There’s several competing problems and priorities, and they’re fairly well represented here.

Experiencing Templates

Despite building individual tanks and the such, the basic maneuver element has remained the division. Like in the third game, these are made up of sub-units, battalions, which are grouped into regiments inside the division. Also like the last game, each country has pre-made division templates that existing units use. However, you are not free to change them however you like this time.

Instead, changing, or creating a new template, requires the use of army experience. This is something gained by combat or a few other limited sources, and is needed to re-form the army into (hopefully) more effective units. Creating a duplicate of an existing template is free, and the general practice is to create new templates rather than just changing old ones, as that forces every division using that template to undergo an immediate organizational change, impacting training and equipment. And if you want to add that new self-propelled gun to your armor divisions, every one will start clamoring for them while production is just tooling up.

Then, you can tell a division to change which template it’s using. (Even to a completely different type!) So you can pick just a couple units to go to the new style immediately, and wait on the rest until the equipment is ready. Sadly, while it’s not hard to find out how many divisions are using a previous template, finding where they are is not easily done.

Non-Standard Models

As ever, the technology sections for equipment have standard slots for everyone. Overall, it’s been simplified a bit, with (for instance) eleven standard models of tanks. Again, we have cosmetics without meaning, as all the major countries have their own names for each model even though they’re identical for everyone.

Or… are they? Part of the government options is that you can assign design bureaus for the major types of equipment, and those provide bonuses to the various statistics. These are not the same for everyone (except the minor countries all get the same set), so once those are in place, a German Medium Tank I won’t be quite the same as an American one.

Further, you can make improved models of all the tank, aircraft, and ship types through use of the relevant arm’s experience (this is the only use for naval and air experience; only army experience is also used to rebuild larger formations). Switching from a general model of tank to the next technology in line saves some production efficiency, and switching to an improved version saves most of the production efficiency. So, especially once the shooting’s started, you can customize the current models instead of waiting for the next major step to be researched and then do a major re-tooling for that.

At first, I was quite disappointed by another round of different names without difference, but once I saw how much you can change things, and the fact that you could imitate Germany’s constant parade of upgraded models during the war, and the production model ties in with this so well, it became a real plus for the game, even if I still have a bunch of nit-picky reservations.

Military Planning

Unlike in HoI III, there’s no corps or full organizational hierarchy this time. However, theaters and armies were retained in a new interface. Theaters are mostly a convenience, and armies are the only level where you appoint commanders now. Also, the idea of tracking if there’s enough officers to properly administer the units has been dropped.

An army has divisions assigned to it, and then you can assign all, some, or none of those divisions to various battle plans for that army. The most common plan is to assign it a section of the front to man, and then assign a place you want to go on the offensive from that line. You can also have units garrison an area, define a new defense line to fall back to, and the like.

There are a number of problems here. This is obviously intended as a more comprehensive version of the AI control seen in III, and the new order modes help, but the problem of not being able to tell the AI how you want it to do things remains. Worse, the UI is not entirely up to the job. It’s actually a good effort, and I expect in later patches it got better, but it takes a lot of practice to get past the problems (which can be gotten past, which is impressive itself).

You can ignore all this and do everything manually. You don’t have group everything into armies, you don’t have to give the armies any orders, but there are incentives for doing so. First, the AI is pretty good at things like distributing units along a line, though it does occasionally get confused. However, when you put in a plan with offensive lines and the such, not only does the AI put the units where needed, but those units will slowly gain a combat bonus. When you hit the ‘go’ button for the attack, that planning bonus helps them deal with the defenders, and you can’t get that manually, but neither can you get it instantly.

And I should note that I finally understand what the combat markers have been trying to say since HoI III, thanks to Stellaris. The two combat systems aren’t anything alike, but what they’re trying to report is similar. The HoI combat tag is a circle with a number from 1-100, that is green, yellow, or red. The latter tells you if you’re currently winning or losing, and the number should be how far through you are… except you can be 95 and red. Or the predicted time a battle will take differs widely when everything else looks the same. In Stellaris, the main combat display primarily shows the balance of combined hull points on each side. The number here (and a similar bar in the full display) is showing the combined balance of organization (effectively cohesion, and a concept that goes back to the original HoI, though only HoI and Victoria has used it), and the color tells you who, at the current rate of loss, will run out and be forced to retreat first.

Areas of Interest

Like in the previous two games, the world is divided into large zones for purposes of naval and air combat. With the new production system you establish air wings, and give them a maximum size, and planes get transferred to it. Once it has aircraft, you assign it to a region within the aircraft’s operating range, and then set the types of missions it will perform.

This isn’t too different from before, with a need to develop airbases, and assign aircraft, but now you can size them at will… and there’s no real guidance on what a good air wing size is.

Naval missions work much the same way, and now combat works much like it does in V II: Heart of Darkness, where ships go through a process of moving into position and picking a target. Light ships and submarines dart in to engage with torpedoes or take out the enemy pickets while the big ships go after their counterparts with the big guns. It’s a much better combat system, and as well suited to WWII naval combat as to pre-WWI, so this is a good upgrade for the series.

Fight With Power

Politics is nicely more complicated than in previous game. There are the usual three factions (Axis, Allied, Comintern), but not just those. The other possibilities are limited, but Japan, for instance, can form the Greater East Asia Co-Prosperity Sphere as its own faction.

At the same time diplomacy works a bit more like other series from Paradox, so they aren’t quite as necessary, either. All the usual defensive alliances, military access, and the like are options here. Wars are similar in that you need to have a justification to go to war, and you can spend time to make a claim on territory to get that. But the peace negotiations are much different. You have to take most of a country to get them to capitulate, which starts a peace conference where everyone involved can start making demands like the more familiar systems in other games.

Some justifications are found in the national focus trees. These are a new system for the series, where eight major countries each have a specific set of focuses that help with the development of the nation (everyone else gets a generic one). These are arranged in trees, that follow a particular theme or goal. They are similar to ideas from EU IV, but those are sets to be chosen, and come in a straight path, while these are all pre-determined, and can have some complex dependencies (so maybe they’re closer to the national bonuses that ideas in EU IV unlock).

Actually unlocking these bonuses uses political power. The other use of political power is to modify the government. There’s always been a bunch of governmental offices, but they started out filled, and were easy to ignore. This time, they generally don’t start out filled, and you use political power to gain new bonuses (and the only penalty for changing bonuses is paying the power again). This is where the design bureaus come in, as well as ministers and military staff for more general bonuses.

In general, government structure hasn’t actually changed much from any of the previous games, but it has been made easier to deal with. The focus trees are an interesting addition, especially as they can guide the AI down non-historical paths. However, I feel they’re too much interference with the root game systems, and the low number of unique ones undermines the system.


For me, the new production model is the centerpiece of HoI IV, and does a lot to get at the nature of the industrial side of the war. Beyond what I’ve said above, equipment also has reliability, so some of it breaks down and needs replacing in use, in addition to the enemy shooting it up. The need to replace both kinds of losses naturally creates a maintenance drag on the industry of a country, and is a good use of a computer’s ability to track numbers not practical in board games.

My problems on the military side are largely down to correctable problems (the planner is way too likely to “drift” to odd frontages, and empty orders and the like), instead of fundamental philosophical differences. One bit I do miss from the previous game is the full unit hierarchy. It needed some more polish, but I was hoping to be able operate corps as a whole in crowded fronts, rather than the separate divisions. That aside, once you learn how to use the military planner (which is not a quick process), it’s pretty good, and lets you become a lot more hands off. In fact, one of the major challenges with it is to stop micromanaging as much as instinct says.

My biggest problem is the focus trees. They’re a neat idea (possibly with a bit of inspiration from Days of Decision, but that’s an international system of events rather than a purely internal one that very occasionally does something to someone else), but underbaked, with seven unique trees in the base game, plus one for Poland in a free DLC that came out at launch (so why isn’t it just part of the game?), and then a generic one for everyone else. While much bigger and more complex than the national bonuses in EU IV, those still point the way to making this much more palatable. The number of different bonus groups grew over time, but even at the start there were a number of generic sets for use with groups of nations. Having 3-4 generic trees from the start would have helped a lot (say one for Asia, one for Eastern Europe, etc.) to say that countries outside the prime movers had any importance in the game. As it is, only countries touched by an expansion have any unique decisions of their own, and countries like Finland are still stuck with the generic tree. (The upcoming ninth expansion for HoI IV will finally do something with them.)

So, once again, I think Paradox missed some major things with Hearts of Iron IV, but they got a lot of things right, and I think it’s the best iteration of the series. I know there are people who disagree, and they have some good points, but the pluses here are pretty big and try to pull back from the trap of more details for detail’s sake. It is still my least favorite series from them, but it is neck and neck with some of the other current games and I do look forward to playing it again.