Hearts of Iron 4 1.12.6 patch notes reinforce HoI4 War Effort

The Hearts of Iron 4 update 1.12.6 releases on Steam in Paradox’s HoI4 War Effort, aimed at providing long-form support for the classic WW2 grand strategy game

Hearts of Iron 4 - India's P Krishna Pillai, a well-kept man in a black suit and tie, set against the Indian map

Paradox begins its HoI4 War Effort in earnest as the Hearts of Iron 4 1.12.6 patch notes arrive alongside the latest HoI4 update ‘Operation Tungsten’ for the beloved WW2 grand strategy game. The War Effort initiative is aimed at providing longer-term support and updates to older countries that may not otherwise be in the scope of more major Hearts of Iron 4 DLC packs. Among the changes included in the HoI4 1.12.6 update are buffs to India and a nerf for the rather overpowered Soviet NKVD advisors, along with tweaks to help new players.

India, traditionally considered one of the weaker HoI4 countries, gets several buffs to multiple focus options along with a new one that allows the offset of the Agrarian Society national spirit. This particular trait has long been a problem for India, as it gives you a not-so-nice 69% penalty to your recruitable population. After many years of the Indian Civil War not giving players any units to fight with, this has now been fixed.

Among the other key notes are a 75% reduction to sir supply mission CP cost, which should buff up air supply options and give players another viable supply resource to employ. The default occupation law has been changed from Civilian Oversight to Military Governor – given that you can manually adjust this when occupying, it’s likely that this change has been made to help out new players with a more reliable default.

Also very welcome is that timed ‘peace stackables’ such as resource rights and war reparations, which are frequently used to resolve smaller conflicts, will now only cancel when at war with the receiver, rather than just when at war with anyone.

Some of the other countries seeing notable buffs in the patch are Hungary, Czechoslovakia, and Romania, with a few small tweaks offered to the likes of Ethiopia and Manchukuo. Meanwhile, Italy has seen some hefty nerfs to some of its stronger focus options that should dampen its overall power level slightly.

There are some rather humorous tweaks in the extensive patch notes, too, but nevertheless quite impactful ones. Paradox reports that “AI is somewhat less likely to blow the Suez canal without reasons” now, which should put a dampener on Mussolini’s apparently rather spontaneous appetit for canal carnage.

Paradox also says that “Soviet NKVD advisors are no longer omniscient beings” as it alters their enemy spy detection chance from a whopping 5% base down to a much more reasonable 0.2% base. There’s also the rather delightful note that “Approximately 2 million people have been returned to Mozambique.

HoI4 game director Peter ‘Arheo’ Nicholson explains the new ‘War Effort’ in a post on the Paradox forums. He remarks, “as you read the patch notes, it may become evident that we’re tackling some different stuff from our usual maintenance patches.” He explains that content changes for older content is something that the team has “wanted to tackle for a while” and that while there is no defined cadence for the updates yet, “it is our intention to continue providing small upgrades to older country content that we may not revisit for some time, in one way or another.”

Hearts of Iron 4 Operation Tungsten – HoI4 1.12.6 patch notes


  •  India now has access to a new focus and series of lengthy decisions which allow the offset of the Agrarian Society national spirit.
  • Imperial Associates can now become spymaster of their faction.
  • Manchukuo focus ‘Hoankyoku’ now grants a free Spy Agency if unbuilt, and a national focus granting +1 free operative slot.
  • Two new one-use war support decisions added, which simulate the effects of radio and film industry propaganda.
  • One new focus added to Romanian air section: ‘White Squadron.’
  • Air supply mission cp cost has been reduced by 75%.
  • Truce period after kicking a country from faction increased to 60 days from 30.
  • Hungary’s Support Urbanization focus now grants one civilian factory in addition to the three building slots. Institute for Industrial Techniques now requires one of the prerequisites, not both.
  • Hungarian spirit ‘Invite Foreign Investors’ now grants 10% research speed in addition to previous effects.
  • Hungary now receives 2 uses of the 25% doctrine cost reduction from the ‘Mobile Corps’ spirit, from 1.
  • Default occupation law is now set to Military Governor, from Civilian Oversight.
  • AI is somewhat less likely to blow the suez canal without reasons.
  • Soviet NKVD advisors are no longer omniscient beings – enemy spy detection chance reduced to 0.2% base from 5% base.
  • Italian ‘Air Innovations’ focus now grants a 50% research bonus, from 75%.
  • Italian focus ‘Reggianes Exports’ now grants 1x 50% bonus, from 2x 75%.
  • Italian Focus ‘Citta del Aria’ now grants 4x 25% bonuses, from 3x 75% research bonuses.
  • Italian focus ‘Standardization’ now provides 1x 75% research bonus, from 2x 75%.
  • Italian focus ‘specialization’ now grants 2x 50% research bonuses, from 3x 50%.
  • Italian focus ‘Incrociatori Leggeri’ now provides 2x interdiction cost reductions, from 3.
  • Italian focus ‘Incrociatori pesanti’ now provides 2x 75% cost reductions for fleet in being, from 3x 75%.
  • Italian Cruiser Sub and Midget Sub focuses now grant 1x 50% cost reductions, from 2x 75% cost reductions.
  • Italian focuses ‘Navi da Battaglia’ and ‘Caccia… Cacciatorpprs… never mind’ now provide 2x 50% cost reductions, from 2x 75%.
  • Italian focus ‘Redirect Alfa Romeo production’ now grants 2×50% research bonuses for light aircraft, from 2x 75%.
  • Italian focus ‘thermojet research’ has been made less powerful.
  • Czech Communist focus ‘Communism with a Human Face’ now grants 3% Recruitable Population from 2%.
  • Czech focus ‘War College’ now grants -100% Field Officer Promotion Penalty.
  • Czech focus ‘Air is Our Sea’ now grants -15% fighter production cost, from -10%.
  • Czech focus ‘Equal Access Guarantee’ no longer reduces heavy tank production cost, but reduces light tank production cost by 15%, from 5%.
  • Czech Fortification focuses (left side) now grant significantly more army experience (10-30 each, from 5 each).
  • Czech Hungarian Line and Polish Line focuses now take 35 days to complete, from 70.
  • Ethiopia: Cost to invite to executive council reduced to 100pp from 150, cost to integrate is now 3% stability, from 150pp.
  • Indian Focus ‘Rhani of Jhansi’ now provides a commander of level 5, from 3 (with associated skill increases).
  • Indian focus ‘Navy Funding’ now provides 50 naval xp, from 20.
  • Indian focus ‘British Army Support’ now grants 2 uses of the 100% research bonus for support technology from 1 use, and 30 army experience, from 20.
  • Indian focus ‘Lions of the Great War’ now provides 30 army experience. The spirit granted by this focus now also provides 5% war support.
  • Approximately 2 million people have been returned to Mozambique.
  • Romanian focuses ‘Invest in the IAR’ and ‘MALAXA’ now grant 3 of their respective factory types, from 2.
  • Romanian focuses ‘Ground Support’ and ‘Air Defense’ now grant 2x 50% doctrine cost bonuses, from 2x 25%.
  • Romanian focus ‘Air Superiority’ now grants 2x 50% cost reduction bonuses, from 2x 25%.
  • Romanian focus ‘The Armored Division’ now grants 2 armored units, from 1.
  • Warscore from taking a province for the first time increased by 50%.
  • Garrison Manpower lost per resistance attack reduced slightly.
  • Small Bomb Bay now has -15 agility, from -20. Bomb Locks now have -20 agility from -15.
  • Several AI modifiers have been added to the ‘Protect Czechoslovakia’ triggered event in the Hungarian focus tree, and a tooltip has been added to indicate what you can do to make it more likely to succeed.
  • Non-strategic materials module now decreases production cost of airframes by 7.5%.
  • Manchukuo focus ‘The Two Emperors’ now reduces the Low Legitimacy malus by 20% war support and stability.
  • Slightly reduced manpower requirements again for lower tier occupation laws.
  • Timed peace stackables (resource rights + war reparations) now only cancel when at war with the receiver, rather than when at war with anyone.
  • The USA now has a significant peace cost reduction for puppeting Japan.


  • Hovered state highlighting is now used in construction and deployment mapmodes.
  • You are once again able to click and shift-click to set the priority on production line elements, using the priority frame indicator.


  • AI will now pick somewhat more interesting military spirits.
  • Slightly adjusted thresholds for AI using occupation laws, towards a more severe approach.
  • If Czechoslovakia is at war with Germany, Germany should now wait a while before declaring war on Poland.
  • Improved air role ratios for countries AI.
  • Gave the AI an extra layer of though process behind taking states in peace conferences. Added several key areas of interest, and reduced their general interest elsewhere.
  • AI contesting other AIs in peace conferences should now resolve their conflicts based on a combination of relative power and map aesthetics.


  • Added pc_turn trigger for peace conferences.

Bug fixes

  • Italy can no longer claim territory or the subjugation through decisions of a Balkan country if they are in the same faction.
  • If Italy tries to join the Stresa Front and has any wargoals on a faction member, they will be removed before Italy can join the faction.
  • Prevent CTD for observer when someone hotjoins.
  • Fix crash when putting the focus on an Edit text box and closing the screen by using the Escape key.
  • World Threat will now correctly build and decay from the fabrication of claims.
  • Fixed inconsistencies with BoP impact in Italy when losing/retaking core states.
  • Switzerland now correctly updates best democratic allies when another country changes governments.
  • Former Presidents of the Swiss Confederation are now available as Councilors again after 1950.
  • Generic versions of Switzerland generated through Peace Conferences don’t inherit Switzerland’s systems or Focus Tree anymore.
  • Indian civil war will no longer give you 0 units if you complete a civil war focus while Free.
  • Herzegovina is now transferred to Croatia if the appropriate event option is selected by Germany.
  • Cairo is now required to form Arabia, and is appropriately cored by the same decision.
  • Forming the Ottoman empire without BftB now grants a core on Cairo. Cairo is now required and cored for the respective decisions in BftB.
  • Constantinople and Amasya are now cored by the Form Persia decision.
  • Ticino is now cored by the HRE decision.
  • Forming Byzantium without BftB will now appropriately grant cores on Constantinople and Amasya. Victory in Egypt and Tunis now requires and grants core on Cairo.
  • Forming Macedonia now requires and grants cores on Istanbul, Amasya, Van, and Cairo.
  • Decision alert should now show again if available decisions are present.

Paradox also notes its next two updates, which will be titled Operation Source and Operation Capital, are in its sights but “things can be quite uncertain so we will work hard on confirming these dates to make sure they are correct” before sharing further details.

It seems likely that this War Effort has been inspired by a record HoI4 player count following the release of DLC pack Hearts of Iron 4: By Blood Alone and a corresponding free week on Steam. If you’ve been inspired to check it out, take a look at the best Hearts of Iron 4 mods and all the Hearts of Iron 4 cheats for some fun console commands to let you experiment with one of the best strategy games for your World War II reenactments.