| Hearts of Iron IV | |
|---|---|
 | |
| Developer | Paradox Development Studio |
| Publisher | Paradox Interactive |
| Directors | Dan Lind (2016-2021) Peter "Arheo" Nicholson (2021-present) |
| Composer |
Sabaton |
| Series | Hearts of Iron |
| Engine | Clausewitz Engine |
| Platforms | Microsoft Windows,macOS,Linux |
| Release |
|
| Genres | Grand strategy |
| Modes | Single-player,multiplayer |
Hearts of Iron IV, also commonly known asHOI4, is a 2016grand strategyvideo game developed byParadox Development Studio and published byParadox Interactive.[1] It is the sequel to 2009'sHearts of Iron III and the fourth main installment in theHearts of Iron series. Like previous games in the series,Hearts of Iron IV is agrand strategy wargame that focuses onWorld War II. The player can control any country in the world, starting either in 1936 or 1939. Players have the option of following a nation's historical path, or leading various non-historical paths.
By May 2018, the game had sold a total of one and a half million copies worldwide.[2][3] As of June 2023, the game has sold over five million copies onSteam alone.[not verified in body] Since its release, Paradox has released large amounts ofdownloadable content forHearts of Iron IV.[4]
Hearts of Iron IV is agrand strategy wargame that revolves aroundWorld War II. The player may play as any nation in the world in the 1936 or 1939 start dates insingle-player ormultiplayer. A nation'smilitary is divided betweenground forces,naval forces, andaerial forces. For the ground forces, the player may train, customize, and commanddivisions consisting of various types ofinfantry,tanks, and other units. These divisions require equipment andmanpower to fight properly. The navy and air force also require men and equipment, including the actualwarships andwarplanes that are used in combat. The tanks, airplanes, and boats could also be manually customised by the player. Equipment is produced by military factories, while ships are built bydockyards. These military factories and dockyards are, in turn, constructed using civilian factories, which also construct a variety of other buildings, produceconsumer goods for the civilian population, and overseecommerce with other nations. Most nations are initially forced to devote a significant number of their civilian factories to producing consumer goods, but as the nation becomes increasinglymobilized, more factories will be freed up for other purposes. Mobilization is represented as a "policy" that the player may adjust with the proper amount ofpolitical power, an abstract "resource" that is also used to appoint newministers and change other facets of the nation's government. In addition to mobilization, there are other policies, including the nation's stance onconscription and commerce.[5]
Land inHearts of Iron IV is divided into tiny regions known as provinces (also called tiles), which are grouped to formstates. Each state has a certain amount of shared and state building slots, both of which affect the whole state, while provinces have province building slots that only impact the individual province. Similarly, major seas and oceans (for warships) and the sky (for warplanes) are divided into different zones known as strategic regions. Sea regions and provinces each have a type ofterrain andweather assigned to them that determines how well different types of units will perform in combat there. Air regions do not have terrain types but still have weather. Divisions are deployed in provinces and can capture enemy provinces and engage in combat. How well divisions perform in combat depends on various factors, such as the quality of their equipment, the weather, the type of terrain, the skill and traits of thegeneral commanding the divisions, aerial combat in the region, supply lines, their organisation, how high their defense or attack - 'soft' or 'hard' - is, and supporting units. Technologies can be researched to improve equipment. Military doctrines can be upgraded by using army XP, among other things, which often means that a more technologically advanced nation will have an edge in combat. If a division (or a group of divisions) successfully overwhelms an enemy province, they mayoccupy it. Some provinces may have victory points, which can push a nation closer towardscapitulation if occupied. Occupying key provinces within a state allows the occupying power to access the enemy's factories andnatural resources in that state.Resistance to occupation within a state, which occurs when a nation does not have a 'core' on a controlled territory, can hamper the occupying power's control over it. Nations can developnuclear bombs if they have the proper technology, which can be used to devastate enemy provinces and states.[6] Since the release of the update coinciding withGötterdämmerung, special projects have been added which require facilities to be constructed to allow for the pursuit of nuclear energy, as well as other technologies such assuper heavy tanks, intercontinentalbombers, orrockets[7].
Hearts of Iron IV also attempts to recreate the complexdiplomatic relationships of the day. Nations may undertake a variety of diplomatic actions; they may signnon-aggression pacts,guarantee the independence of other nations, and offer or requestmilitary access, amongst other things. Another key feature of diplomacy is the ability to create afaction or invite other nations to an existing one. Factions represent the main alliances of the era, like theAxis andAllies (for gameplay purposes, real-world factions like the Axis and Allies are split into numerous smaller factions, like theComintern, theChinese United Front, and theGreater East Asian Co-Prosperity Sphere). Faction members may assist each other in wars, making faction members precious assets. Some more clandestine diplomatic actions are also available. For example, the player mayjustify war against other nations, spread theirideology abroad, or stage acoup. Countries in the game may bedemocratic,communist,fascist, ornon-aligned. Each of the four ideologies has advantages and disadvantages; for example, fascist nations can go to war with other countries easily, but other nations are not as willing to trade with them as they are with democratic countries. If a nation's ideology is non-aligned, then it can be several things. For an example, if the German Reich loses acivil war, a monarchist party is created, which is non-aligned. If a different ideology becomes too popular in a country, areferendum may be held that will peacefully convert the nation to the most popular ideology. Otherwise, ideologies may come to power violently through coups, civil wars, orforced subjugation by a foreign power.[8]
This diplomacy is further expanded through the addition ofespionage in the expansionLa Résistance, which extends gameplay in the management of occupied territories which is done differently according to player choices and ideology. Furthermore, the operation of spy networks allows nations to steal technology, gather information on an opponent's military, and engage in other espionage efforts.[9]
WhileHearts of Iron IV does feature somescripted events, the game features a "national focus" system that makes fixed events less necessary than in previous installments in the series. Each country in the game has a "focus tree" with various "national focuses" that grant certain effects or trigger events. For example, for theAnschluss to occur,Germany must first complete the focus that is related to it. Other focuses can grant special bonuses, like faster research times for certain technologies or extra factories. While some bonuses (like extra factories) are very tangible, others (like improvements to morale) are more abstract. These abstract bonuses are represented by "national spirits" that can be temporary or permanent. Not all national spirits are granted by focuses, and not all spirits are entirely beneficial. Focuses are completed over time; only one focus may be worked on at once, and working on one consumes some political power. Initially, only a handful of key nations, like Nazi Germany, the United Kingdom, the Soviet Union, and the United States, had unique focus trees; all other nations shared a generic one. Subsequent updates andDLCs have added focus trees to other nations as well.[10]
Hearts of Iron IV also introduces the concept of "world tension", an abstract representation of how close the world is to global war, on a scale from 0 to 100. Aggressive actions by any nation can increase world tension, while peaceful actions can decrease it. Depending on the circumstances of a nation, like their ideology, a certain level of world tension may be necessary to perform certain actions, like justifying war against another country.[11]
Hearts of Iron IV was announced in 2014 and was originally slated for a late 2015 release.[12] AtE3 2015, creative directorJohan Andersson confirmed that the game would be pushed back from its original release window, with the new release date being scheduled for the first quarter of 2016. This was an attempt to resolve several issues encountered with the game.[13] In March 2016, it was announced that the game, built with theClausewitz Engine, would be released on 6 June 2016, which was the 72nd anniversary of theNormandy landings.[1]
Hearts of Iron IV has also received many free updates since the launch of the game (16 major with over 100 in total[14]).[15] These often coincide with DLC releases, and add new content or change content for the base game.
| 2016 | Together for Victory |
|---|---|
| 2017 | Death or Dishonor |
| 2018 | Waking the Tiger |
| 2019 | Man the Guns |
| 2020 | La Résistance |
| Battle for the Bosporus | |
| 2021 | No Step Back |
| 2022 | By Blood Alone |
| 2023 | Arms Against Tyranny |
| 2024 | Trial of Allegiance |
| Götterdämmerung | |
| 2025 | Graveyard of Empires |
| No Compromise, No Surrender | |
| 2026 | Thunder at our Gates |
| Peace In Our Time |
Hearts of Iron IV has received severalDLC ever since its release. This has included a variety of new content for the game, including graphical additions such as newarmor models[16] or new music packs such as the collaborations with the Swedish power metal bandSabaton[17][18].
Hearts of Iron IV has several different types of DLC that change gameplay elements. This includes:
| Name | Accompanying patch | Type | Release date | Description |
|---|---|---|---|---|
| Together for Victory[a][19] | 1.3 "Torch" | Country Pack | 15 December 2016 | Together for Victory is a country pack that adds content to multiple nations within theBritish Empire:Canada,Australia,New Zealand,South Africa, and theBritish Raj. It also expands the gameplay mechanics betweenpuppet states and their masters, with a special autonomy system that determines a subject nation's degree of independence. Features like an expandedLend-Lease system and the sharing of technology are also added.[20] The country pack was later integrated into the base game. |
| Death or Dishonor[a][21] | 1.4 "Oak" | Country Pack | 14 June 2017 | Death or Dishonor is a country pack that adds content to several minor powers inCentral Europe and theBalkans, which includeYugoslavia,Romania,Czechoslovakia, andHungary, while also featuring the ability to license military equipment to other countries.[22] IfTogether for Victory is not owned, the expansion also adds limited puppet levels to the game. Following the release of the 1.10 "Collie" patch, content for Yugoslavia and Romania was reworked.[23] The country pack was later integrated into the base game. |
| Waking the Tiger[a][24] | 1.5 | Expansion | 8 March 2018 | Waking the Tiger is an expansion that fleshes out theSecond Sino-Japanese War with new content forJapanese-controlledManchukuo, as well asNationalist andCommunist China, and a shared focus tree for theChinese warlords ofGuangxi,Yunnan,Ma,Shanxi, andSinkiang. The expansion also adds new opportunities foralternate history within the focus trees ofGermany andJapan, which were expanded, and several new formable nations were added. In addition, special projects and policies can be enacted with unique decisions, and several changes to the management of generals are present in the expansion.[25] The expansion was later integrated into the base game. |
| Man the Guns[26] | 1.6 "Ironclad" | Expansion | 28 February 2019 | Man the Guns is an expansion that improves the naval combat aspect of the game with the inclusion of aship designer, although numerous other changes and new features are also present in the expansion, such as adding content for theNetherlands andMexico and also including new alternate history paths for theUnited States and theUnited Kingdom. The expansion also addsfuel as a resource separate from oil, andgovernment-in-exile mechanics.[27] The expansion was later announced to be eventually integrated into the base game.[28] |
| La Résistance[9] | 1.9 "Husky" | Expansion | 25 February 2020 | La Résistance is an expansion that addsespionage and occupation mechanics. Intelligence is greatly expanded, while occupation and resistance are completely reworked. The expansion also includes a revamped focus tree forFrance (includingFree andVichy France), a new one forPortugal, and two focus trees for the different sides of theSpanish Civil War, one for theNationalists and one for theRepublicans. It also allows the civil war to spiral into a much bigger conflict.[9] |
| Battle for the Bosporus[29] | 1.10[b] "Collie" | Country Pack | 15 October 2020 | Battle for the Bosporus is a country pack that adds unique focus trees forGreece,[31]Bulgaria,[32] andTurkey.[33]. With the accompanying patch focus trees forRomania andYugoslavia were also updated.[34] |
| No Step Back[35] | 1.11 | Expansion | 23 November 2021[36] | No Step Back is an expansion that adds railroads,armored trains,railway guns, and atank designer, with the possibility of customising chassis, weapons, and engines. It also introduces the general staff and adds unique focus trees to theBaltic countries, and a reworked one for theSoviet Union. An additional free update reworks thePolish focus tree.[35] |
| By Blood Alone[37] | 1.12 | Expansion | 27 September 2022 | By Blood Alone is an expansion that adds new peace conference options, aplane designer, unit medals, and embargo interaction. It also includes a reworked national focus tree forItaly, as well as new national focus trees for bothSwitzerland andEthiopia.[38] |
| Arms Against Tyranny[39] | 1.13 | Expansion | 10 October 2023 | Arms Against Tyranny is an expansion that adds unique focus trees for theNordic countries, customizablespecial forces units and a system for selling equipment between countries.[40] |
| Trial of Allegiance[41] | 1.14 "Bolivar" | Country Pack | 7 March 2024 | Trial of Allegiance is a country pack that adds unique focus trees forArgentina,Brazil,Chile,Paraguay, andUruguay.[42] |
| Götterdämmerung[43] | 1.15 "Kaiser" | Expansion | 14 November 2024 | Götterdämmerung (German forTwilight of the Gods) is an expansion that centers onspecial projects andmilitary raids. It also features updated focus trees for Germany and Hungary while adding new ones forAustria,Belgium, andthe Congo.[44] |
| Graveyard of Empires[45] | 1.16 | Country Pack | 4 March 2025[46] | Graveyard of Empires is a country pack that adds unique focus trees forIran,Iraq, andAfghanistan, as well as revamping theBritish Raj.[46] |
| No Compromise, No Surrender[47] | TBA | Expansion | 20 November 2025[48] | No Compromise, No Surrender is an upcoming expansion that will focus on improved military doctrines, an expanded faction system, and improved naval mechanics. It also includes new focus trees forJapan,Nationalist China,Communist China, and thePhilippines.[49] |
| Thunder at our Gates[50] | TBA | Theater Pack | Q2 2026[51] | Thunder at our Gates is an upcoming theater pack that will add new focus trees forAustralia,Siam, and theDutch East Indies. It will also add military HQs and ship captains.[52] |
| Peace For Our Time[53] | TBA | Focus Pack | Q2 2026[54] | Peace For Our Time is an upcoming focus pack that will add a new focus tree forCzechoslovakia. This will also be the first gameplay-changing DLC forHearts of Iron 4 that will feature content created bymodders of the game.[55] |
On 4 April 2024,Together for Victory,Death or Dishonor, andWaking the Tiger were integrated into the base game and are no longer sold separately or considered DLC.[56] On 23 September 2025,Man the Guns was announced to also be integrated into the base game upon the release ofNo Compromise, No Surrender, and has been made free to purchase.[28]
Hearts of Iron IV was developed to be more open-ended than previous games in the series. Partially as a result of this, the game can be more readilymodded than its predecessors.[57] According to game director Dan Lind, 64% ofHearts of Iron IV players use mods.[58] The game is written inParadox’s Clausewitz Engine, a version ofC++.
Mods can be found onParadox Mods and theSteam Workshop. Many mods do not change the gameplay experience drastically, and as such have become mainstays of the community, for example, 'Player-Led Peace Conferences', which gives the player more control over the outcome of postwar peace conferences. Other mods encompasstotal conversions that change the game significantly, usually through the use ofalternate history scenarios, different starting scenarios, or adding content to the game. Some mods have been successful enough to attract attention from the media, such as the following:
Some other mods have also attracted controversy, such asMillennium Dawn, that allows players to take control of any country in the modern day, including theIslamic State's caliphate, andDeus Vult, a now-removed mod that allowed players to take control of theKnights Templar and commit variousatrocities.[67]
| Aggregator | Score |
|---|---|
| Metacritic | 83/100[68] |
| Publication | Score |
|---|---|
| GameSpot | 8/10[69] |
| IGN | 9/10[70] |
| PC Gamer (US) | 88/100[71] |
Hearts of Iron IV was a commercial success.[2] It sold more than 200,000 units within two weeks of its launch, which made it the fastest-selling historically themed Paradox title by that time, ahead ofCrusader Kings II andEuropa Universalis IV.[72] The game's sales surpassed 500,000 units in February 2017,[73] and 1 million units in May 2018. It was the firstHearts of Iron game to reach the million mark, and the third Paradox title afterCrusader Kings II andEuropa Universalis IV to do so.[2] The game received "generally favorable reviews" from critics, according to the review aggregatorMetacritic.[68]
GameSpot gave the game a positive review, writing that "Hearts of Iron IV embodies the hard truths about all-consuming war and the international politics that guide it." It argued that the tutorial was the only weak point, and that "for the dedicated,Hearts of Iron IV could end up being the best grand strategy game in some time."[69]
It was also reviewed inKotaku, with the reviewer writing it was "overwhelming in both its depth and, more importantly, its complexity" and arguing that some players unfamiliar with the franchise might find the game interface too complex to navigate easily.[74]
IGN wrote a positive review, describing it as "an incredibly complexWorld War II simulation that will require potentially hundreds of hours to master, both in-game and poring over wiki articles that read like an economics textbook", but adding that "the payoff is brilliant for those willing to put in the time to learn". The review praised the layout, writing "thanks to an unusually striking look and clean, easily navigable interface, the biggest challengesHearts of Iron 4 presents us with are the good kind: strategic planning, division composition, and fine-tuning economic and political policies".IGN went on to conclude thatHearts of Iron IV "is a strong contender for the title of the ultimate armchair-general game. The biggest problems I can point to are almost all performance-related, putting a slow, frustrating finale on what is otherwise an ingeniously detailed strategic stimulation of just about every aspect of 20th-century global warfare".[70]
A review inPC Gamer described it as a "unique, beautiful, thrilling wargame", specifically praising its frontline system and production mechanics, but also criticising the ideology system for being too bland, and finding that combat was somewhat unintuitive, writing "while I found several flaws when I stood close to the tapestry, it's important to remember thatHearts of Iron 4 exists to encompass the whole sweep of the war".[71]
Polygon praised the openness of the game, writing that "Hearts of Iron 4 goes a step further, allowing players to take control of nearly every single nation-state in the world during the same period. If you want to play asEleazar López Contreras, a Venezuelan fascist with two army divisions and 12 fighter planes to his name, you can give it a go".[75]
In 2022, six years after the game's release and shortly after theBy Blood Alone expansion,Hearts of Iron IV hit a concurrent player record of about 70,000,[76] owing to a week-long deal that temporarily made the gamefree-to-play. The year prior, the game had reached a record of 68,000.[77]
Hearts of Iron IV was banned inChina on November 2, 2017, shortly before the announcement of theWaking The Tiger expansion for "a claim that the game does not comply with local law."[78][79] This is despiteTencent, a Chinese game-developer, buying 10% of Paradox interactive on May 27, 2016.[80]
China had previously bannedHearts of Iron in 2004 for "distorting historical facts" by depictingTibet,Manchukuo andWest Xinjiang as sovereign countries and for havingJapan control Taiwan, all of which were fact but did not comply with China's mandates over spin.[81]
