08 Aug


PDXCON returns to Stockholm this September! Meet the devs, join a massive board game session, attend Paradox games’ orchestra & play our games!

Get the tickets while supplies last! [paradoxinteractive.com]

02 Aug

PDXCON2022 returns to Stockholm this September! Join us on the road to PDXCON2022 with another Grand Campaign!

Watch our developers as they play through a customized game of Crusader Kings, Europa Universalis, Hearts of Iron, and Stellaris and follow laws passed by our Community-led Senate. Following the great tradition laid down last year for PDXCON, there may be familiar faces, returning arch-rivals, and maybe some new friends!

What is a Grand Campaign?
The story of a Grand Campaign is written in the senate, where Community-formed and led parties propose and vote on laws, that our developers have to follow on stream. This Grand Campaign spans the timeframe of four of our games, spanning several thousand years of alt-human history. Starting in the Crusader Kings era, all the way to Stellaris. In between games, we wil... Read more

29 Jun

MAJOR DISCLAIMER - This dev diary is written before the majority of art has been delivered, so it features a lot of placeholder graphics - you have to imagine really cool focus icons, and a lot of characters with hats that are beyond fabulous, for example

But we have some cool art coming!

Work in progress image of Ethiopian Irregular Infantry

So, I was asked to write a dev diary about the development of a focus tree and related stuff for Ethiopia. Mainly because I was the one asked to do Ethiopia in the first place*, I guess. It would probably have felt weird to do a dev diary on something else then…

Anyway, Ethiopia. I wanted to make playing Ethiopia a somewhat different experience than the average game of HoI. It has to be, right? For one, Ethiopia starts at war, which puts some constraints on the design. Als... Read more

01 Jun


Hello there, C0RAX here. Welcome aboard to my dev corner, in this thread I'll be going over the core introduction of the planned changes to naval gameplay.

Why? The Live System:
  • Good ship design is unintuitive.
  • Combat revolves around exploiting oversights
  • Ahistorical meta

  • Clearer design process
  • Meta based upon good structure and multiple key values
  • Making historic choices in naval design and composition work well in game

Rebalance Overview
  • Tech Tree
  • Ship Designer
  • Hit profiles
  • S...
Read more

18 May


Hey Everyone! I am back this week to talk to you a bit about some changes we are making to air management and combat. The first thing I want to get out of the way is that this is not a “Man the Guns” style rework of combat and management systems. Our focus on air changes have mostly revolved around quality of life and balance changes to existing systems, while largely maintaining the structures people are familiar with (with a couple of exceptions). So, let's get into it!

Starting off with a QoL change I am very happy about: Simplified Wing Deployment. Anyone who has experience with managing air wings probably has some complaints about how deploying wings works. The live system requires three clicks in the best case (four if you include choosing a base) to deploy a single wing into an empty airbase. In the worst case this requires... Read more

04 May


And we shall have peace...

Hi folks,

It’s been a while since our last update on future plans for HoI, but we’re about ready to show you some of the work we’ve been doing. Before we begin, I’d like to indicate that there’ll be some differences in how we do this. As I’ve previously stated, we want to begin discussion around features and implementation details a little earlier in the process than usual. This means a couple of things.

Firstly, while we’ll be showing off some individual features, we’re not yet ready to give an overview of the entire scope of our next release yet. This will, of course, be coming in the near (ish) future.

Secondly, you’ll be getting an early look at what we’ve been working on, and this comes with all the caveats you might expect: lots of WIP design, interface, and gameplay... Read more

07 Apr

The frontlines are expanding! Our community is making an operational push onto a new platform! That's right, D(iscord)-Day is upon us!


Patch 1.11.10 "Barbarossa"
- Added a bypass to the Free French "Form the National Committee" Focus to avoid blocking the player if they don't have 90 Legitimacy
- Fixed a problem in British Alternate Strategy Plans when historical focuses are off without a specific strategy plan being selected
- Fixed issue where Estonia and Latvia would not follow the historical focuses
- Added missing leader tooltip in Soviet focus The Glory of the Red Army. Pavel Rybalko will become a general after completing the focus, and now everyone knows it.
- Turkey no longer gets a wargoal on themselves when refusing Balkan Federation demands
- Niche Role will now be correctly set correctly when AI designs ships. This also applies to players using "auto design".
- Japanese puppets should now get the corrects name
- Fixed achievement "Better than Szent Istvan" being impossible to earn due to a an issue with the new character system
- Naval battles will no ... Read more

01 Apr


Greetings commanders!
As you’ll be aware, it has been a while since our last dev diary, and I’m super thrilled to finally release what we’ve been working on since No Step Back.

We take great pride in our attention to gameplay telemetry that we receive from keen HOI4 players from across the globe, and our data wizards regularly furnish us with relevant information with which to steer development of features. After NSB, we were informed of a clear and scientific trend in the data:

That’s right folks, it turns out that 99.5%* of you exclusively play monarchies. It was quite clear to us that we had a mandate to finally concede to public demand, and add the long-awaited Habsburg bra... Read more

23 Feb

Hello there, the time has come to do a fun dive into what you've been playing the game as a community. So over this diary we are going to look into some of the trends and statistics we seen from our telemetry and see how we use it to gain insights in current player trends when working on HOI4. The wonderful data team have been working to get us all the information we wanted and I hope you enjoy seeing some of their great work. As a forward point, as with any data collection we do not store any personal information or anything that can used to identify players in accordance with GDPR.

So first of we will start with something fun, can you guess what this graph is telling us.

If you guessed this was us spotting the continuous naval production focus exploit being discovered you get a gold star, although it seems some of you are... Read more

17 Feb

Patch 1.11.7 "Barbarossa"
- Added a Career Profile where players can view statistics about their playthrough
- Added promotion for the new DLC Subscription

15 Feb


Greetings Generals! We have two big things to talk about today so let's dive into it. First of all Hearts of Iron 4 is joining other PDX titles, and gaining an additional way to experience our catalog of DLC through a subscription model. If you have any questions about the subscription service, farther down the post there is a FAQ, and we’ll do our best to answer any questions you have in the comments.

Second, and unrelated to the subscription service, all players will have access to their “Career Profile” from the title screen in Hearts of Iron 4. This will track information about your time playing HoI, from this point forward. It will look like this!

And if you own any DLC (or are... Read more

14 Feb

Patch 1.11.6 "Barbarossa"

Balance - Flattened tank chassis IC cost, raising earlier chassis by 10-20%, up to no change at later chassis.

- Transport planes now cost fuel to run.

- Reduced truck damage from logistics strike mission by approx 30%, reduced train damage from logistics strike mission by approx 15%

Modding - Fixed dynamic modifiers not returning localized keys when supplied

- set_nationality effect will no longer check if the character is 'available' in the target country before transferring them

- set_nationality on characters will no longer cause their owning country to reset to their original country on loading savegame. This addresses several CTDs and some unexpected behaviour

Stability & Performance
- Fixed OOS and other subtle issues caused by bad ordering of logistics stockpile in deployment logic

- Fixed CTD with mods that fire leaders without giving AI a proper 7 days n... Read more

09 Feb


Greetings all!
As you’ll no doubt be aware, the launch of the No Step Back expansion last year was the climax of a busy year of development for the HoI team, and it continues to be one of our best received releases to date.

Of course, the last year also saw the departure of @podcat as Game Director who was reassigned to Siberia greater things at Paradox. Many of you will also have read the roadmap document that was produced towards the beginning of HoI4 development, and are asking questions as to the veracity of that plan under a new director, and whether I have any different ideas or plans to announce.

Looking Forwards
I mentioned at the beginning of my tenure that both @podcat and I see HoI4 in broadly similar terms. This hasn’t changed, and you can expect to see many of the parts of the previous roadmap make an... Read more

27 Jan

Patch 1.11.5 "Barbarossa"

# AI
- Majors will now send volunteers to the Spanish Civil War even without La Resistance
- AI will no longer consider enemy lakes to be dangerous
- AI has learned the definition of insanity and will now try to avoid attacking in same place if previous invasion failed
- AI will be more careful with their attacks if they start running out of manpower
- AI now assigns free aces to valid existing wings instead of only when creating new wings
- AI is now significantly less likely to release collaboration governments unless they have narrative reasons to do so

# UI
- Supply map mode allows normal interactions with naval unit counters and doesn't hide fleet windows
- Fixed ship stats details pages not showing correct supply usage
- Fixed UI elements highlighting spurriously when tech template would unlock equipment which isn't included in current DLC profile
- Fixed Army and N... Read more

14 Dec

Patch 1.11.4 "Barbarossa"

# Balance
- Reduced compliance gain bonuses in advisor and country leader traits from 0.1 to 0.05. Kamenev will now provide 0.02 compliance bonus as advisor, and 0.05 as country leader.
- Reduced weekly stability bonus and replaced weekly war support bonus by a flat one in Stalin's traits.
- Slightly reduced weekly War Support and PP gain on Stalinist campaign. Reduced XP gain and Breakthrough bonus on For the Motherland campaign.
- Army and Navy Spirit cost adjusted down to 20/35/50 from 25/50/75. Air spirits now all cost 50 air experience.
- Naval bases now cost 5000 IC (from 3000), and incur an extra cost of 1000 per additional level.
- Air Supply mission fuel costs increased by 50%
- Increases hub Max Motorization cost to 80 trucks, from 50
- Democratic government type now confers a bonus of -25% political advisor cost. Several national spirits have been slightly tweaked down to accomodate the p... Read more

25 Nov

Fixed - Armor 3D units from previous addons showing in the Tank Designer
The expected models can now be selected for tank designs
Game executable should be properly signed again

23 Nov

Greeting Generals! No Step Back is here! With it the Barbarossa patch and a new checksum. 1.11.1 and bf90.
And if you would like to enjoy is in Russian version (This is the one I like more)
Bellow you will find a brief breakdown of what is included in the free patch, and what is in the DLC, the full patch notes can be found {LINK REM... Read more

17 Nov


An early look at our Patch Notes are available on our forums. Unfortunately, the notes are too large to fit onto steam in this format, an official patch notes post will accompany the release next week.

I will also take this opportunity to point out that as is normal for large updates, saved games from earlier versions will not be compatible with No Step Back. An opt-in rollback to the current live version will be provided when No Step Back and the Barbarossa update launch


10 Nov


Hello, and welcome back to another Dev Diary for Hearts of Iron 4. As we close in on wrapping up this major operation, code-named Barbarossa, before winter falls (the first snow fell in Stockholm this weekend, I am sure it’ll be fine), today we will talk about the new achievements that will be added with the release of No Step Back.

As far as the process is concerned, we usually have an open list of achievement suggestions during the whole DLC development cycle. Near the end of the cycle, we take a vote on what achievements we want to see in the game (after eliminating any that would be technically impossible) and start the process of implementing them and ordering art.

For No Step Back, we started with a list of 49 suggestions, and whittled it down to 20 Achievements:

... Read more