HOI IV Open Beta Update VI Patch Notes (May 2026)

Paradox has dropped Open Beta Update VI for Hearts of Iron IV, and according to developers Niels and Batya, this is intended to be the last beta update before the full Anniversary Patch goes live on June 6th. Whether it actually is the last one depends on player feedback, but the notes are substantial enough that it feels like a pre-release tidy-up rather than a holding pattern.

The biggest wins are on the naval AI side. The AI now reserves more dockyards for repairs and won't stop until critical damage is actually addressed, two changes that should stop the frustrating pattern of your allies sending battered ships straight back into combat. Nationalist China also gets a meaningful speed boost, with 22 focuses cut from 70 days down to 35, which should make that faction considerably less painful to play through. Submarines escape more slowly now too, dropping from 50% to 35% progress per day when hidden, so hunting them down carries a bit more weight.

On the achievements front, Paradox shared that community survey data is pointing them toward a bespoke system where some achievements require ironman and others don't. Nothing locked in yet, but it's a more sensible direction than a blanket requirement. Here's everything that changed.

Generals!

Here is another Open Beta Update for our upcoming Anniversary Patch, including some bugfixes, balancing and more naval AI improvements.

We recently posted a survey as a way to check the community pulse, and it has given us interesting data. When looking at the data and the responses on social media, the majority of you believe that ironman should not be required for getting achievements, however playing with mods should suppress getting achievements. We also hear the outcry for allowing specific mods and achievements, but this is unfortunately unfeasible for us. Quite a few people also talked about the potential of getting achievements when playing multiplayer. We’ve not decided on a specific course yet, but we are leaning towards a more bespoke achievement unlock requirements. Meaning that some will require ironman, and others don’t.

For now, this is intended to be the last update to the open beta before it goes live closer to our actual anniversary, on June 6th. However, we still might tweak balance, based on feedback!

I just want to also say that the feedback has been invaluable on this open beta, and has pointed us towards all the right directions. I hope you feel that with these updates the naval AI is in a good place again, and that we continue to improve the game for everyone. Thank you 🙏

/Niels, Batya

How to Join this open beta:

This beta client is Case Green v1.18.2.0.9c2d (fbec)

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 Update VI Notes

Balance

Nationalist China: Reduced focus time from 70 days to 35 days for 22 focuses across the Industry, Army, Air, Navy and Politics branches
Nationalist China: Construct the Banqiao Dam moved earlier in the tree; The National Sun Yat-sen University takes its previous prerequisites
Submarines now escape at 35% progress per day if they are hidden (previously 50%)

Gameplay

Lendlease has better UI logic and will default to maximum amounts that the receiver can handle with their convoys
An event will now be fired to all the signatories of the Nine-powers treaty when China gets attacked
Ignore convoy limit when sending convoys as a lend lease

AI

Updated USA naval templates and strategy
Updated generic & UK's ship templates
AI now reserves more dockyards for repair (thank you forum feedback)
The AI will now repair until critical damage has been repaired (thank you forum feedback)
UK builds up north africa port more if its needed to push to Tobruk

Bugfix

Crash that can occur when a SAM mission is set to a naval region
Crash that can occur on Mac in peace conferences
Fixed bug where emergency convoy demand would scale infinitely
Force creation of new GPU buffer by running the first map of the frame with DISCARD
Fixed a bug where a ship would gain strength through doctrines, on reloading a save they would be damaged
Fixed a bug where planes destroyed by other sources than air to air combat did not count towards war participation (as an example: static anti-air or destroyed planes in a raid)
Raj: Fixed "Mixed Economy" giving resources on all owned states rather than starting states and added coal
Raj: Fixed "The riches of the Raj" to check for synthetic refineries as well
Raj: Fixed "Acquire new Resources" so it gives the resources to the correct state
CTD that could occur with scientists in late game
Fixed a bug where a naval supply tooltip would show a much larger number of convoys required then was actually needed

And finally, in case you missed it: To show off all the Australia content, Mordred and Punchrullar will be hosting a live stream today at 15:00 CEST!