Hearts of Iron IV HOI IV - Open Beta Summer Edition (6th July 2026)

Generals!

Greetings from sunny Stockholm to everyone, I’m Batya, Game Director for Hearts of Iron. The summer period is upon us and I wanted to share some information with you all. Unlike the norm of armies planning summer offensives, game developers actually do the opposite and take time off.

Of course I am not here to just tell you we will be out for the summer, instead I want to talk about the Open Betas we’ve been running in the last few months.

Some of you might have seen, or even opted into, the betas that we ran for Naval changes and also the Anniversary patch. First of all a big thank you to everyone who involved themselves and provided feedback. It is important for us to co-operate with our community to make a better game and that is exactly what we want to do more of.

I’d like to introduce another beta initiative codenamed ‘Sommarfältprov’, which mainly aims at re-balancing different parts of the game. One of the bigger ones has been, for example, Regimental Support that did not entirely hit the mark balance wise. Some other ones are (Sub)Doctrines as well as the long and arduously discussed Line Artillery.

These are all things that we want to take a stab at for the betterment of the game. The person spearheading this over the summer-y period will be Zwirbaum and he will be the main person to inform about changes happening on that branch. He will also fill in a bit more on what to expect so I will happily hand over the proverbial mic to them.

Have a wonderful summer y’all!

/Batya

Hello, I’m Zwirbaum, Game Designer for Hearts of Iron, and I want to welcome you all to this new Open Beta, Summer Edition™. Similarly to how we had Open Naval Balance Beta run during the Spring, where efforts were mostly focused on adjusting the balance and fixing some of the issues for the naval aspect of the gameplay, this time I will be taking a bit broader look across the game balance and some of the pain points of Hearts of Iron IV.

What is changing for this Open Beta Summer Edition™ - as opposed to the Naval Balance Beta? During the spring I found out that trying to keep up with the weekly update cadence on top of my regular responsibilities, was imposing too much of pressure on me, which meant that I had a bit less time to think about certain things, respond and participate in the discussions with the community and to proceed with the actual implementation and changes. This time there will be no guaranteed or any REGULARLY planned update cadence. Also as we are entering Summer period, there is a small chance that my posts may be a bit more irregular in what they would contain, in order to keep it vacation themed somewhat. So less lengthy posts, with a lot of dry information, but either more concise posts, or a bit more unusual content? This time we may also have more experimental changes that will take more time to reach full maturity.

What is not changing from the previous Naval Balance Beta? Once again there is no guarantee that this Beta will be integrated into a main version, when or in what form it would happen, not to mention that it would of course depend on the feedback we would be getting from you, our dear community.

For more comments on what is changed, and why, check out for the developer commentary in the specific sections in the Patch Notes.

Thanks for reading, and until next time, Farewell!

/Zwirbaum

How to join this Open Beta:

This beta client is Operation Postern v1.19.2.0.40eb (f387)

To install Open Beta client, follow the instruction below:

• Right-click the game in your library
• Select Properties from the drop-down menu
• Select Game Versions & Betas
• Select the beta branch called open_beta

If you are already on the Open Beta client, you should get an update automatically.

Finally, to report any issues you find, in relation to this beta, please use the bug report forum and make sure to include the version you’re using. That way our Jira won’t go nuts trying to figure out what bug report belongs to what.

Open Beta Summer Edition™ Notes

Gameplay

• Battalion Adjusters now scale with the Equipment and Manpower status of the Sub-Unit. E.g. Super Heavy Artillery with Siege Artillery Sub-Doctrine no longer gives Army wide Soft-Attack Bonus due to the sheer force of will and imagination.
• Added Essential (Equipment) Blocks for the following units: Heavy Weapons Company and Motorized Heavy Weapons Company, Light Flame Tank, Medium Flame Tank, Heavy Flame Tank, Headquarters Staff, Engineer Staff, Reconnaissance Staff, Military Police Staff, Maintenance Planning Staff, Hospital Group Staff, Logistics & Service Staff, Signal & Intelligence Staff, Naval Liaison Staff, Forward Air Controller, Special Operations Coordination
• Adjusted Essential (Equipment) Blocks for the following units: Helicopter Med-Evac, Helicopter Transports

Developer Commentary: First change should fix the unintended player behavior when adding certain units for their Battalion Adjusters, like Super Heavy Artillery and then turning off the usage of such equipment and still getting the benefit of the modifiers from Siege Artillery. And even if players did not intend to abuse the system, any losses suffered from combat/attrition would not apply any effect to that Battalion Adjusters. Second change is that there were quite a number of units that because they lacked essential equipment defined that would result in them not scaling their modifiers and effects due to the potential lack of equipment. Tank Crews riding in pretend Flame Tanks will no longer confer the sense of bravery and invincibility that would let them attack enemy fortifications or cities at ease.

Balance

Superior Tactician Admiral Trait now provides +15% Positioning Bonus instead of +25%

Surface Detection Impact on the positioning has been reduced from maximum +25% to +15%

Admiral Maneuver Skill impact on the positioning has been reduced from +2.5% per level to +1.5% per level.

Admiral Maneuver Skill impact on naval retreat speed has been increased from +1% per level to +2% per level.

Developer Commentary: Positioning while exists as an interesting concept, in practice it was way too easy to counter-act massive doom stacks by just various plethora of the modifiers providing a lot of positioning benefits. This should give a bit more of a breathing space for the natural positioning penalties to occur and happen in-game. As the Naval Combat is already quite deadly, and retreating ships have hard time to disengage from the combat, increasing the speed with which ships can retreat could help save a couple ships here and there. This change is of a more experimental nature.

• Combat Bonus from division experience decreased from 25% to 20%. Green Divisions now have -20% Combat Penalty, Trained have 0%, Regulars have +20%, Seasoned +40% and Veterans have +60%.

Developer Commentary: Experience bonus to the Land Units resulted in a massive boost to their combat capabilities as all modifiers during combat are multiplicative with each other depending if they belong from ‘different source’ that 75% bonus could result in a massive sway of the effective stats. This is a relatively modest reduction, but we may explore squishing that effect a bit or reworking it to have non-linear progression in the future.

• Air Crew Surveys Air Spirit Mastery gain for individual tracks got combined into Air Doctrine Mastery gain Factor.
• Dive Bombing Air Spirit CAS Design cost reduction got replaced with +15% Strike Aircraft Mastery Track gain Factor.
• Material Destruction Air Spirit Medium Airframe Design cost reduction got replaced with +15% Medium Aircraft Mastery gain Factor.
• Industrial Destruction Air Spirit Heavy Airframe Design cost reduction got replaced with +15% Heavy Aircraft Mastery gain Factor.

Developer Commentary: The goal of changing the Design Cost reductions on them is to replace: pay the air XP in order to potentially save some air XP down the line when designing more planes. However with the current amount of air XP incoming from the combat and missions, there is rarely a situation where as a player you feel starved out on the Air XP - in order to make a design, and if you really can’t make a design, then paying those 50 Air XP upfront isn’t helping with that goal either. Hopefully giving them a more dedicated and focused effect on the specific mastery track will make them somewhat more competitive. I will monitor feedback on this one as well - so depending on the feedback we may see doing further adjustments or going back to the original one.

• Increased naval targeting values for naval bombers for fully screened capitals from 10 to 15
• Increased naval targeting values for naval bombers for fully screened carriers from 10 to 25

Developer Commentary: One of the changes we did with the No Compromise, No Surrender release was to equalize the base weights for all ships when it comes to being picked as targets by the Naval Bombers, when screening value is 100%, and the old prioritization would be kicking in when the screening efficiency depending on how much screening was missing. While targeting would also take into the account strength of the ships (their HP, making Battleships even with equal base weights technically being a bit more of a viable target than ‘Early Destroyer’) - the result, especially with the meta depending on spam of the masses of the destroyers, would make them rarely targeted. The old behaviour where Carriers and Capitals ships being almost always prioritized with full precision, was not ideal either. Hopefully with this change, or a couple more tweaks, we will still have a possibility where all damage is NOT focused on big ships, but also isn’t fully soaked by the screens either, resulting in a more spread out damage across the fleets and the taskforces. Carriers performance and their planes during naval battles should also hopefully get better results.

• Continuous Strike Air Spirit - Air Support Efficiency bonus has been reduced from 25% to 15%.
• Massed Strike Air Spirit - Air Superiority Effect has been increased from +5% to +10%
• Support Artillery now has -50% to Soft Attack, Hard Attack, Defense and Breakthrough from previous -40%
• Support Rocket Artillery now has -50% to Soft Attack, Hard Attack, Defense and Breakthrough from previous -40%
• Support Anti-Air now requires 24 equipment pieces from the previous 20
• Motorized Anti-Air now belongs to the Anti-Air Unit Category
• Anti-Air Unit Category has been renamed to Anti-Air Artillery Support & Line

Developer Commentary: This renaming will be only localized in English for now, if we will go further with these changes, we will localize it properly for all the languages.

• Anti-Tank 1940 Technology no longer provides randomly Motorized Anti-Tank with +10% Piercing and +10% Hard Attack
• Light, Medium, Heavy and Modern Self-Propelled Artillery Combat Width increased from 2 to 3

Developer Commentary: With the release of No Compromise, No Surrender we made balance adjustment to Self-Propelled Artillery so that their Combat Width was reduced from 3 to 2. This however had quite a big impact on the ‘stat bloat’ and increased offensive powers, resulting in certain combinations of units having much . With keeping (at least for now) Regular Artillery still at 3 Combat Width, we will try out bringing back SP-ART to the previous combat widths.

• Naval, Land and Air Facilities cost has been lowered from 12000 to 10000. Scaling cost per facility has been increased from 5000 to 6000. This means that the first and second will be cheaper (10000 and 16000 vs 12000 and 17000) . The third one will have the same cost, while starting with the fourth of the same type, they will become more and more expensive. This should make entering the world of Special Projects easier for smaller & less well developed nations. Nuclear Facility will remain at the current premium cost for now.
• Improved Amphibious Designs now reduce Amtrac production cost by 10% instead of 15%
• Helicopter Brigade and Helicopter Logistics now will have a proper Fuel Consumption instead of having -100%

Regimental Support Companies Balance

• Heavy Weapons Company and Motorized Heavy Weapons Company Organization has been increased from 20 to 30.
• Heavy Weapons Company and Motorized Heavy Weapons Company Max Strength has been increased from 0.4 to 0.6
• Infantry Guns and Rocket Battery Equipment needed was increased from 4 to 6
• Infantry Guns and Rocket Battery stat adjustments have been normalized and are now -75% to Defense, Breakthrough, Soft and Hard Attack. (Previously it was (-80%, -60%, -70%, -60%)
• Anti–Air Battery Equipment needed was increased from 12 to 16 and Manpower needed from 120 to 180
• Anti-Air Battery Breakthrough, Soft Attack and Hard Attack penalties were lowered to -60% from -80%
• Anti-Tank Battery Manpower needed was increased from 120 to 180
• Soft Attack penalty from Anti-Tank battery has been lowered from -80% to -60%
• Light, Medium, Heavy and Modern Tank Destroyer Regimental Support units are for now excluded from the ‘Tank Destroyer’ category. They still benefit from the Tank Destroyer Regimental Support category.
• Light, Medium, Heavy and Modern Tank Destroyer Regimental Support units now require 15 Tank Destroyers instead of the previous 10. For now I will refer to them as TD-RS (Tank Destroyer Regimental Support)
• Light, Medium, Heavy and Modern Self-Propelled Anti-Air Regimental Support units are for now excluded from the ‘Self-Propelled Anti-Air Artillery’ category. They still benefit from Self-Propelled Anti-Air Regimental Support category
• Light, Medium, Heavy and Modern Self-Propelled Anti-Air Regimental Support units now require 15 Self-Propelled Anti-Air instead of the previous 10. For now I will refer to them as SPAA-RS (Self-Propelled Anti Air Regimental Support)
• TD-RS and SPAA-RS: Fuel Consumption for them has been increased from 33% of the equipment to 40% of the equipment
• TD-RS and SPAA-RS: Armor Value reduced from -33% to -66%
• TD-RS and SPAA-RS: Defense lowered from -25% to -50%
• TD-RS and SPAA-RS: Soft-Attack lowered from -33% to -66%
• SPAA-RS: Air Attack reduced from -15% to -25% and Hard Attack from -33% to -66%
• TD-RS: Hard Attack reduced from -33% to -50%
• TD-RS and SPAA-RS: Artillery Technologies impact on them for Hard Attack and Air Attack has been lowered by half after the full tech tree progression (From +30% Hard / Air Attack on them lowered to +15%)

Developer Commentary: Regimental Support Companies have been vastly overperforming when it comes to both their contribution in the pure stats, and especially compared to their low economical requirements. After this balance they should feel less overpowered and be closer in-line with what should be expected out of them. This doesn’t rule out any further tweaks to them. Also for the time being the armored regimental support companies will be excluded from the main Tank Destroyer and Self-Propelled Anti-Air unit categories to make sure that the buffs aimed at those regimental support companies will be adjusted and tweaked separately, giving more control over what and in what magnitude each buff is applied to. Main Categories will likely be renamed to indicate that they refer to: Battalions, or ‘Line Units’.

• Infantry Guns no longer get benefits from Infantry Support Weapons research, and instead get their benefits from Artillery tech tree improvements.
• Infantry Guns and Rocket Battery scaling effect with technologies has been reduced. (+5% Soft Attack for the Infantry Guns per Artillery Technology, +10% Soft Attack for Rocket Batteries from Rocket Artillery technologies, and +5% Soft Attack from the Improved Guidance). Infantry Guns no longer have Defense boost from the Technologies.

Line Artillery Balance

• Artillery, Motorized Artillery, Rocket Artillery, Motorized Rocket Artillery, Truck Drawn Rocket Artillery, Anti-Tank, Motorized Anti-Tank, Anti-Air, Motorized Anti-Air Max Strength increased from 0.6 to 0.8
• Artillery Equipment I stats have been adjusted to provide following stats: Soft Attack +1 (from 25 to 26), Defense +1 (from 10 to 11), Breakthrough +4 (6 to 10)
• Artillery Equipment II stats have been adjusted to provide following stats: Breakthrough +6 (from 7 to 13), Hard Attack +1 (from 2 to 3), Piercing +2 (from 5 to 7)
• Artillery Equipment III stats have been adjusted to provide following stats: Breakthrough +8 (from 8 to 16), Defense +1 (from 18 to 19), Hard Attack +2 (from 2 to 4), Piercing +4 (from 5 to 9)
• Rocket Artillery Equipment I stats have been adjusted to provide following stats: Defense +1 (from 12 to 13), Breakthrough +8 (from 9 to 17), Soft Attack +2 (from 30 to 32)
• Rocket Artillery Equipment II stats have been adjusted to provide following stats: Defense +1 (from 15 to 16), Breakthrough +8 (from 12 to 20), Soft Attack +2 (from 38 to 40)
• Motorized Rocket Artillery Equipment stats have been adjusted to provide following stats: Defense +1 (from 15 to 16), Breakthrough +8 (from 12 to 20)

Developer Commentary: This is our starting point to increase the viability of the Line Artillery. We have heard and thought about various different approaches for making them more viable, including lowering their Combat Width from 3 to 2. However in the current environment where Regimental Support Companies, and all the various imbalances did exist, and the excessive ‘stat’ bloat as it was called was present - we have decided for now against taking that step. To make the presence of the Artillery - be a more viable tool in providing the combat stats other than Attack values (mainly Breakthrough), which should make Infantry supported by the Artillery a little bit more viable on the attack. We will continue working and tweaking on the Line Artillery to find the right spot for it.

Doctrine Balance - Land Doctrines

• Mobile Infantry 1 Reward: Cavalry Recon now receives bonus 10% to Defence and Breakthrough
• Mobile Infantry 3 Reward: Lowered Soft Attack Bonus to Infantry Guns and Rocket Batteries from +15% to +10%, now also increases Defense and Breakthrough by 5%
• Mobile Infantry 5 Reward: Motorized Heavy Weapons Company gets +10 Organization from +5
• Defensive Postures 1 Reward: Heavy Weapons Company now also receives +0.2 Entrenchment
• Defensive Postures 4 Reward: Soft Attack bonus to Infantry Guns and Rocket Batteries reduced to 10%
• Assault Infantry Adoption Bonus: Bonus to Support Artillery attack has been increased from +10% to +20%
• Assault Infantry 1 Reward: Bonus to Infantry Guns removed
• Assault Infantry 2 Reward: Bonus to Anti-Tank Battery and Anti-Air Battery reduced from +10% to +5% (Hard Attack, Piercing, Air Attack)
• Mounted Infantry 4 Reward: +0.05 HP to Mounted Infantry unit category was replaced with the battalion adjusters to the Cavalry Recon to give +5 flat HP to the Mounted Infantry
• Mounted Infantry 4 Reward: Reduced the Speed Bonus to Cavalry Recon and Cavalry to +40% (for a total of 8 kph instead of the previous 8.4 kph)
• Mounted Infantry 5 Reward: Increased Speed Bonus to Artillery, Anti-Air, Anti-Tank and Rocket Artillery to +100% (for a total of 8 kph)
• People’s Militia 2 Reward: Infantry Guns Soft Attack bonus reduced from 15% to 10%. Infantry Guns now get +10% Breakthrough
• People’s Militia 3 Reward: Now requires 50 Mastery like the other rewards in this doctrine.
• Great War Infantry 3 Reward: Support Artillery now provides +10% Bonus to Breakthrough to Leg Infantry from previous +5%
• Great War Infantry 3 Reward: Infantry Guns and Rocket Battery now provides +10% Soft Attack bonus instead of +20%
• Great War Infantry 5 Reward: Now also provides +5 Max Entrenchment
• Fire Concentration Adoption Bonus: +5% Defense bonus to Line Artillery changed to +10% Breakthrough bonus
• Fire Concentration 1 Reward: +5% Defense bonus to Line Artillery changed to +10% Breakthrough bonus
• Fire Concentration 3 Reward: +10% Breakthrough Bonus to Line Artillery and Support Artillery changed to +10% Defense Bonus and +5% Soft Attack Bonus increased to +10%. Bonus to Infantry Guns and Rocket Batteries removed.
• Fire Concentration 5 Reward: Bonus to Artillery and Rocket Artillery removed. Infantry Guns and Rocket Batteries now get +10% Defense and +10% Breakthrough
• Anti-Tank Frontline 1 Reward: Bonus to Anti-Tank Battery brought in-line with Line Anti-Tank. Anti-Tank Support now also receives the same bonus.
• Flying Batteries 1 Reward: Motorized Heavy Weapons Company removed from the reward
• Flying Batteries 3 Reward: Armored Signal Company now provides +0.2 Strength (from 0.8 to 1) to Line Artillery.
• Air Cavalry 2 Reward: 0.03 HP bonus is now being replaced with Maintenance Company Battalion Adjuster to the Helicopter Support Companies, giving +0.5 HP to each
• Mobile Recon and Support 5 Reward: Breakthrough bonus to TD-RS and SPAA-RS changed to +5% Hard Attack and +5% Air Attack respectively
• Self-Propelled Support Adoption Bonus: Soft Attack bonus reduced to +5%, Air-Attack bonus reduced to +5%
• Self-Propelled Support Reward 2: Soft Attack bonus provided by Recon units reduced to +5%
• Self-Propelled Support Reward 3: Speed Bonus reduced to +10% from +30%
• Self-Propelled Support Reward 4: TD-RS and SPAA-RS now get +5% Hard Attack and +5% Air Attack respectively, and +5 Organization
• Siege Artillery 2 Reward: Plains Movement bonus to Super Heavy Artillery and Self-Propelled Super Heavy Artillery replaced with 0.1 Recovery Rate
• Siege Artillery 4 Reward: Urban Bonus Attack reduced from +20% to +10%, and added Urban Defence Bonus of +10%. Soft Attack bonus to Infantry Guns & Rocket Battery reduced from +10% to +5%
• Armored Spearhead 3 Reward: SPAA-RS Organization bonus reduced from +10 to +5
• Armored Infantry Support 2 Reward: Piercing Bonus removed for TD-RS
• Armored Infantry Support 5 Reward: Air Attack reduced to +5% and removed Organization Bonus
• Mobile Defense 3 Reward: Air Attack for SPAA-RS removed
• Mobile Defense 4 Reward: TD-RS Organization bonus increased to +10, other benefits to TD-RS removed
• Tank Destroyer Force 5 Reward: TD-RS other benefits than the Organization were removed for them.
• Mission Type Tactics Adoption Bonus: Daily Command Power gain has been increased from +0.02 to +0.2

Developer Commentary: This is likely just a start of tweaking the doctrines. We may see doing a bigger balance pass or some redesigns moving forward, depending on the feedback received for them.

Doctrine Balance - Naval Doctrines

Developer Commentary: Tweaks to Naval Doctrines will happen next time

Doctrine Balance - Air Doctrines

Developer Commentary: Tweaks to Air Doctrines will happen next time

Bugfixes

The Light Tank Destroyer Regimental Support unit now has the Soft Attack penalty as the rest of TD Regimental Support Units.

As you were!