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Why Kaiserreich is the ultimate Hearts of Iron 4 mod

The Emperor of all Hearts of Iron 4 mods uses a fictional universe to bring out the game's true storytelling power

Hearts of Iron 4 Kaiserreich mod propaganda image

On Sunday, April 19, 2019, Kaiser Wilhelm II returned from his long exile to reclaim his throne. By which I mean to say that Kaiserreich: Legacy of the Weltkrieg, the extremely popular mod for Paradox Interactive’s World War 2 grand strategy game Hearts of Iron 4, has been updated for the game’s latest patch and is once again playable.

For the unacquainted, Kaiserreich is an alternate history total conversion mod that takes place in a world in which Germany is victorious in the First World War. Originating in Hearts of Iron II, the mod has existed in various incarnations throughout the series in the past decade. With an over 30,000 strong subreddit, and an active discord community, it has an incredibly dedicated fanbase — many of whom eschew the base game and play only Kaiserreich — creating fanart, fiction, AARs, and a flood of in-joke memes.

Recently, the developers have even launched a community store where you can buy merch, and have plans to use that as a launching pad to produce animated original shorts set in the mod’s universe. At this point it has become a veritable institution in the larger, heavily mod-focused Paradox Interactive community, but, whereas many successful HOI4 total conversion mods are based on some existing IP — Old World Blues, a Hearts of Iron IV mod based on the Fallout universe is a good example of this — Kaiserreich is an original work, and one that has even spawned its own collection of spin-off mods based on the universe the developers have created.

This article was originally published in April 2019.

Hearts of Iron 4 Kaiserreich mod main image

One sure sign of the mod’s success is that its popularity prompted Paradox to include their own “version” in the base game by giving Germany an optional path that allows you to expel the Nazis by force and establish a military junta which, in turn, recalls the deposed Kaiser Wilhelm II from exile. The attempt, while admirably done and fun in its own right, fails to capture the magic of the mod’s universe.

Which begs the question: what is the essence of Kaiserreich’s success? Why has the mod survived multiple incarnations over more than a decade? As someone who has played hundreds of hours of both the base game and the mod, I believe this success, particularly in the Hearts of Iron IV incarnation, can be found in some structural issues with the base game that this mod has been effective at resolving.

Particularly, the design choices that guide Hearts of Iron limit the narrative choices available to the player, while Kaiserreich uses its alternate-history setting to recraft the world and add a level of dynamism that simply doesn’t exist in the base game.

Kaiserreich: Still the best Hearts of Iron 4 Mod German focus tree

Historical Fidelity vs. Player Choice

I try to stay away from World War 2 games. The period is, by far, the most well-trod ground in wargaming, and in history in general for that matter. More ink, screen time, and simulated blood has been spilled on the topic than most other historical conflicts combined. Despite becoming a bit hackneyed, Hearts of Iron IV does a serviceable job of making the period feel fresh through the use of its National Focus system, which allows you to direct your nation down a series of branching paths through military, economic, and political choices. This system is the Hearts of Iron IV answer to the central design dilemma in most grand strategy games: the delicate balance between a desire for historical realism and a desire for player choice.

Choose your path: Read our Hearts of Iron 4 DLC guide

In all of Paradox Interactive’s mainline grand strategy titles, this balancing act is present. At longer timescales, this problem is solved by a combination of genericizing certain historic events (for example the Protestant reformation in Europa Universalis IV is an event that can happen after a certain time but will happen semi-randomly within a geographic area; this isn’t the Protestant Reformation, it is a Protestant Reformation). Other times, the technology required to take certain actions will be time-locked, unable to appear until a set year or require enough research points that it will only happen roughly around when it did historically. The least intuitive method is to have set historical events that fire off at a particular date.

Kaiserreich: Still the best Hearts of Iron 4 Mod event screen

The problem with this approach is that it becomes more difficult at smaller timescales. In Europa Universalis or Crusader Kings II there are hundreds of years of game time, so as long as they convey a general sense of the period, most players still feel like they are experiencing a satisfying level of verisimilitude while also believing their choices matter and effect the world around them.

In Hearts of Iron 4, the real meat of the game happens over the course of only about a decade, and of that time, only the choices in about the first five years will have any very meaningful impact on the composition of the war as a whole. This severely condenses the possibilities of player choice, as all three of the methods mentioned above used to create opportunities for player choice at a macro-level are rolled into the game’s National Focus system.

This system is designed to give the player agency, but to do so in a controlled way that allows the game to maintain its tempo and keep the world on a mostly historical track. Through the use of this system, the game is choreographed and most effectively balanced to play out historically, with the major powers hitting all the major period landmarks on the road to war. There is an option to leave historic National Focuses on, forcing the AI to go down the path each nation did historically, or the player can turn this off and allow each nation the possibility of going down a weirder path and slightly throwing a wrench into the mix.

Kaiserreich: Still the best Hearts of Iron 4 Mod campaign introduction screen

However, nations taking ahistorical routes can result in some strange hiccups, as players must sacrifice a degree of the tempo. Factions going down different routes interrupt the game’s careful timing, occasionally resulting in handicapping the side that diverged historically.

In the aforementioned branch of the Germany tree that allows you to reinstall the Kaiser, for example, the player will find themselves at a disadvantage as they have wasted valuable time and resources fighting a civil war instead of mobilizing the economy for the coming struggle.

Play it cool: Read our review of HoI4’s premier Cold War mod

Frustratingly, in the end, even if the player diverges a bit historically, the overall makeup of the conflict will most likely be recognizable enough to anyone with a passing knowledge of the Second World War. Unless something really strange happens there will still be Allies.

There will be an Axis. France will probably fall. The Soviet Union will probably be invaded. Successive playthroughs will vary, but overall the story will remain the same and on a grand strategic level, the decision environment will only change slightly, something which has always grated on me in a conflict that those in America, Europe, and elsewhere are brought up to know so very much about.

Kaiserreich: Still the best Hearts of Iron 4 Mod solutions screen

This is both a design issue and a narrative one, and one which has no clear answer to resolve. The design of the game pulls the “story,” such as it is, in a particular direction. In a purely operational or tactical game, this would be less of a problem, as those types of games live and die in the micro-level decisions, but in a grand strategy game, a feeling of repetitiveness at the very highest macro-levels can leave a player feeling like they are going through the motions of a conflict they already know inside and out.

Kaiserreich attacks this problem at the root by unshackling the world from the historical record in 1917. From that point of divergence, the developers created a rich, well-researched, and lovingly crafted world that retains an air of historical fidelity without requiring the game to be chained to the historical reality of our inter-war world. Clearly, a large part of the success of the mod comes from this fact: it is an interesting scenario interestingly realized. I find it is best to look at the world of Kaiserreich and its lore as a well-researched, historically possible (though hardly plausible) scenario designed for maximum entertainment value. Whereas Hearts of Iron walks a delicate tightrope between fidelity and choice, the Kaiser has his cake and eats it too.

In the Kaiserreich universe, the Wilsonian Europe of our timeline is replaced with a Wilhelmine one in which the German Empire reigns supreme as the undisputed hegemon of a great central European empire strung together with a collection of eastern client states. The Empire also rules over an enormous and contiguous African colony, Mittelafrika, and is the reigning colonial master of a patchwork domain of southeast and east Asian protectorates, including a vast Chinese trading conglomerate.

Kaiserreich: Still the best Hearts of Iron 4 Mod Europe map screen

All these states are tied into Germany’s mutual defense alliance: the Reichspakt. Germany is extraordinarily powerful but also spread incredibly thin. It must hold together the status quo, whatever the cost, even if that means overcommitting in far-flung colonies. Austria-Hungary, the other major victorious Central Power, has survived intact and remains outside Germany’s military orbit. Rather than looking outward, the Habsburg domains are, at the games outset, about to undergo a major consolidation process led from either the center-left or center-right.

Make history: Read our Hearts of Iron 4 tutorial

In the west, Britain and France have fallen to workers’ revolutions and communist governments now sit in London and Paris — their political and military alliance is known as the Third International. Unlike in our own timeline, however, French syndicalism, not Russian bolshevism, is the preeminent ideology of the world’s left-wing revolutionaries. The faction is also allied with the Socialist Republic of Italy, which took control of the north of that country after Victor Emmanuel’s Kingdom fragmented after the war. The former British, French, and Italian governments have fled to Canada,  Algeria, and Sardinia, respectively. From there, the Entente, the third major faction in the mod, stews and broods, opportunistically waiting for a moment of chaos to reclaim their homelands and restore what they believe to be legitimate rule.

Kaiserreich: Still the best Hearts of Iron 4 Mod India map screen

For many, this is the main appeal of Kaiserreich. You inhabit a world which is superficially similar to the one we all know so well — there are three major factions, one is communist, Germany leads another, Britain and France still carry the banner of the Entente from the last war — but at the same time, it reflects a world of radically different possibilities, a strange funhouse mirror of our own historical reality, distorted but still ultimately recognizable. It is also a world that is set up to represent a three-way conflict in which all three of the major factions are competing against each other for control of the same territory. The narrative conflict at the heart of the mod is best summed up by the three taglines of these factions: Guard the Balance, Break the Chains, Reclaim the Birthright.

The unshackling of the game from the historical record also opens up the possibilities that the writers of the lore need not remain beholden to the limitations of the history when crafting the geopolitical landscape. So long as the world remains possible, and rooted in an overarching historical justification, the world can be crafted into an environment that makes for the most interesting experience possible.

Areas of the world that, in our timeline, remain quiet and peaceful, can be made dynamic and interesting.

Additionally, by making the mod diverge from actual history the developers have been able to mine the historical record for bizarrely interesting characters and place them into positions of power, people like the White Russian officer Roman von Ungern-Sternberg, the Hapsburg “Red Prince” Wilhelm, American demagogue Huey Long, failed fascist leader Oswald Mosley, and Manchurian warlord Zhang Zuolin. Where all these characters failed historically, Kaiserreich dredges them up into the games gonzo-historical wonderland of wild possibilities and sets them loose against each other.

Kaiserreich: Still the best Hearts of Iron 4 Mod China map screen


By jettisoning the actual world of 1936, the mod can also have considerably more set-piece secondary struggles that precede the coming World War, similar to the Spanish Civil War in our own timeline.

In the Kaiserreich universe, however, virtually every region has some similar kind of struggle — there is a three-way Spanish civil war, a too-many-sides-to-count American civil war that can drag in other factions, an Arabo-Persian coalition to take down the lumbering Ottomans, a Fourth Balkan War, an Argentine Civil War, a contest for control of the Indian sub-continent, the possibility of revolutions in both French and German Africa, as well as in German Indochina.

20th Century foxholes: Read our guide to the best WW2 games

The allure of Kaiserreich is that it takes a game based on a largely bipolar war and makes it maddeningly multi-polar. Some of the above-mentioned events won’t happen every game, others will fizzle out or end quickly in a decisive victory, and in that uncertainty, that dynamic and chaotic world, is where the success of Kaiserreich lies.

These set-pieces fire off at a steady clip, so that even if one part of the world is quiet, you can gawk at the unfolding chaos somewhere else or participate by sending volunteers to aid the side that has a possibility of benefiting your faction. Turning the tide in one of these struggles might just allow you to open up a new flank or prevent one from opening behind you. The sheer number of these set-pieces, combined with the wide range of ideological paths and sub-paths given to most large nations, means that the map hardly ever looks the same way twice.

Kaiserreich: Still the best Hearts of Iron 4 Mod North America map screen

The Wildcard Powers

Like in the base game, though, the looming and inevitable World War provides the meat of the games overarching narrative. A revanchist France will inevitably confront an overstretched Germany.

What makes the mod’s version of the Second World War more engaging is that while both are titanic struggles, the Second Weltkrieg is aided by both the above mentioned set-pieces, which leave the world dynamic and uncertain, riddled with geopolitical landmines, and the fact that the late game is improved considerably by a number of large wildcard powers that spend most of the early and middle game consolidating before ultimately entering to help sway the balance in the Second Weltkrieg, namely Austria-Hungary, Russia, and the United States.

After each of their respective consolidations, each has options to enter the war and attempt to tip the balance or take advantage of the ensuing chaos. Whereas in the base game once the tide turns and one side gets a clear advantage the rest of the game becomes a long slog of mopping up and intractable foe, in Kaiserreich, a clear-cut war can rubber-band back to balance once one of the wildcards tosses their weight into the fray.

Kaiserreich: Still the best Hearts of Iron 4 Mod Austrian empire focus tree

All of these factors — the expertly realized alternate timeline, the interesting characters, the introduction of more set-piece struggles and wildcard factions — combine to create a game that is fundamentally more dynamic than the base game on which it was built. This dynamism makes each playthrough much more varied and therefore, most importantly, more replayable than the base game.

This is not chaos for chaos’ sake, however. The world of Kaiserreich incorporates this dynamism into the greater narrative of the game, demonstrating how rising instability can undermine a global order, no matter how firmly entrenched it appears from the outside. It is a story of the end of a moment and the rise of revanchist and opportunist powers. It is a story that resonates far more with our own time than does the actual Second World War.

If any of this has piqued your interest, I suggest you take a dive into the newly updated version compatible with the games latest Ironclad update. The introduction of fuel mechanics can throw a wrench into several of the faction’s carefully laid plans. As in actual history, the oil fields of Romania and Azerbaijan become almost essential to hold to keep the war machines of the European powers running, further stretching Germany’s political commitments, while more accurately representing the fuel difficulties Britain and France would have if they were severed from their overseas holdings. It adds another layer of realism into a game in which logistics are largely abstracted. Check it out. This is a mod that is well worth your time.

For a break-down of Hearts of Iron 4’s other must-have mods, as well as a quick introduction to getting started in the modded game, make sure you check out our guide to the best Hearts of Iron 4 mods.