• We have updated our Community Code of Conduct. Please read through the new rules for the forum that are an integral part of Paradox Interactive’s User Agreement.

HOI4 Dev Diary - AI & Feature Updates

Hi everyone! From the time we show off features in dev diaries and release a lot happens. Usually it's just bugfixing and work behind the scenes, but sometimes it can be bigger changes too. So today we will pick out some stuff that's changed since you last read about it. But first, but not least, lets talk a bit about AI development!

AI Updates
When we started with 1.9 'Husky' and La Résistance there were 2 main things we wanted to achieve. First we wanted to nerf Germany (without actually nerfing them) by giving resistance more teeth. This worked pretty well, as after we had made the new resistance system Germany would consistently collapse to large Polish uprisings behind its lines and needed to be told how to manage all that as well as control its equipment production better. Resistance is now constantly hurting garrisons and you don't pre-build garrisons, so stockpiling and not rushing units is more important.

The second thing is also related to Germany (its WW2 after all). For HOI (no matter the version really) we have always striven for a balance where Germany defeats the Soviet Union if the allies do not take pressure off by invading. This ensures that all of the big sides need to be active and if played by a player you need to step up. Now before we jump to the 10 pages of comments discussing if this is a realistic target... It is, for gameplay I think. History wise I am personally convinced that the Soviets would have beaten Germany on their own. It just would have taken a lot longer and been much costlier, and there isn't much point in playing the UK or USA if Soviets will just take care of Germany on their own (now now, please keep reading the rest of the diary before we start arguing what-ifs :p).

Anyways, in 1.7 the allies seldom pulled off invasions well enough, and pretty much only if they got lucky in Italy or punched up through Greece or something like that. Firstly we have made a bunch of improvements and bugfixes to weird parts of the invasion logic for the AI that makes them perform better. The biggest impacts came from limiting the AI from shipping troops back and forth across the globe and simply getting them to buffer up its forces in specific allied territories. USA specifically here will now station troops ahead of time in UK so that when its time to do invasions they are already in the neighborhood. We have also improved prioritization of different fronts to make sure AI gets the importance of Europe and when landings have been made successfully.

One of our most important tools when working on high level AI stuff and history tuning is the "History Logger".
This is a tool that we developed to observe AI gameplay. When enabled, it collects & dumps data on how game progressed during a particular run and its output looks something like this when run through a web interface:
output.gif


You can find two example runs here if you want to experiment with it:
https://common-assets.paradoxplaza.com/hoi4-devdiary/history_viewer.html?zip=1.zip
https://common-assets.paradoxplaza.com/hoi4-devdiary/history_viewer.html?zip=2.zip
Watch out they are very javascript heavy and take a long time to load up :)

Other than showing country borders, it can also show many other other details for a selected country such as diplomacy status, army/navy mission/air mission positions, orders, taken decisions/focuses/ideas, executed operations/operative missions and many other things. On top of that, the things are logged using log effect will also appear in these logs so you can have custom logs in your effects if you want. Here is an example from USA:

upload_2020-2-17_14-32-21.png


The lines are invasion orders and red heat map is the army of USA. You can already see that USA successfully invaded southern France and has invasion plans for Northern France and Denmark.

And here is an example to things that are logged. Logs are filtered by country tag ENG and "operation" and here we see all operations that are executed by England.
upload_2020-2-17_14-48-59.png


We use this tool every day in our nightly automated tests. Everyday we run a bunch of AI only runs with history logger is enabled and at the end of the day we get an email like this:
upload_2020-2-17_13-58-7 (1).png


Our nightly tests inform us if the game is crashed or not, if there are some tests that failed and if there are performance issues. In this particular example in one of the machines Germany was not able to beat France. When we check history logger output for that particular run we see the following:
ger_fails.gif

(Green: Germany. Red: Enemies. Blue:Allies. Yellow: Potential Enemies. Heat map is the army position for Germany.)

In this run we see that Germany is attacking low countries way too early, before Poland falls and the front north west front is prepared. This allows France & England to be better prepared and push through. The fix was to add extra safety checks (we had broken some old ones too in an unrelated change a while back) for how the AI wants to feel prepared for this push.

This tool will be included with 1.9 so modders can take advantage of it. We think is going to be super good for anyone doing balance, AI or total conversion mods. There will be more info on that as well as some more details and info on how to set up the tests in the Friday diary :)


Espionage Changes
We have done some changes to operative recruitment. Rather than being a timer on actual operatives recruitment time the system now is tied to the actual slots you have.
upload_2020-2-19_10-46-12.png

This was needed because the old system was pretty confusing in practice, and giving more operatives from events, or historical operatives would really mess with the progression of the system so UK could gear up its agency way too fast.

Operations have also had a bunch of changes. The more visible one is the addition of the Outlook indicator:
upload_2020-2-19_10-57-4.png

This breaks down risks and the potential for better rewards on an operation. Both can be affected by agency upgrades and Operative traits. A 10% risk means that there is 10% something goes wrong. This usually means that the operatives will need to go into hiding for a while to avoid local investigations, or have suffered an injury, or more rarely, have been captured, killed or turned to the other side. When operations end you'll get to find out as risk trigger generally when trying to extract from the operation area.

We have also added some new ministers for nations. Having an Illusive Gentleman will be a good choice for those who want to go all in on making the strongest Agency possible:
upload_2020-2-19_11-7-40.png

You can also see that UK will get access to all programmers hero Alan Turing if they develop a cryptology department. He is more of a UK special though.

Portugal Changes
Hello everyone, Mano de Zombi here!
As many of you have already noticed, there have been some changes to the Portuguese Focus Tree since my last DD before Christmas, and today I’d like to talk a little bit about them.

Let’s begin with the National Spirit Unstable Republic:

01 Unstable Republic.png


The previous stability penalty (a flat 10%) has been changed to a -0.5% weekly stability penalty.
Salazar’s trait has also been changed from a flat stability bonus to a 0.5% weekly bonus.

As you can see, one stability modifier counters the other. The reason behind this is that while Salazar is in power, his Unstable Republic will be roughly under control. Stability might not increase but it will not decrease either (after all, even with some difficulties, Salazar historically managed to keep the Republic under control for decades).
But once you start tweaking your politics, you can find yourself in a tough situation where low stability might not be easily recovered, putting your country on the brink of civil war before changing your government. More on this later in the diary.


Now let’s take a look at the final focus tree:

02 Portugal tree.png


As you can see, there are some new focuses (12 to be precise), for a total of 122.
During Christmas I worked on a design for the historical Salazarist branch, as well as a bit of reworking and additions to other branches. Big kudos to Pedro, the original FT designer, who helped me a lot and provided me with incredibly useful documentation!


The Military branch looked quite small so we decided to include three more focuses. This branch has also seen some changes, so let’s take a quick look:

03 Military Branch.png


Army Organization, Metropolitan Army and Corpo do Estado Maior will each grant some Army XP. In addition to that, Army Reorganization will remove Unstable Army National Spirit and add a small stability penalty(-5%).

To the left, Metropolitan Army also grants two research bonuses, followed by a production bonus under Standardization. The defensive focuses have not been touched, you must still choose between heavy fortifications in Lisbon or a light fortification line along the coast. Finally, Portugal has two focuses that provide research bonuses for special forces.

Tropas Paraquedistas is based on the Parachute Rifle Battalion, a group of 12 Timorese soldiers trained in Australia during World War II to be launched in the rearguard of the Japanese forces occupying Portuguese Timor; as you can guess, this focus gives a research bonus for Paratroopers.

Regimento de Comandos is a reference to the (later) historical Portuguese Commando Regiment (a special forces unit prepared for counter-guerrilla operations) formed in the early 60s, as a consequence of the Ultramar War; it will provide two research bonuses for special forces, as well as a National Spirit that will slightly increase your special forces limit.

To the right, we have Corpo do Estado Maior, which improves army leaders and makes them cheaper, followed by Staff Wargames and its two research bonuses for land doctrine. Finally, Field Maneuvers will add more Army XP and an additional research bonus for land doctrine.

A final note on this, if you support a Spanish faction during the Spanish Civil War, you can access a focus that also gives you some research bonuses (different bonuses depending on the faction you support):

04a They Need our Help.png


04b Observation Mission.png


04c Assist the Requetes.png



Moving on to the political branch, you can see that some focuses have changed names. This is to clarify that they are related to the Spanish Civil War:

05 Focus Renamed.png


You may also notice that Securing the Free World is now available only through Allow Free Elections (aka Democratic path). This focus will guarantee the independence of every European minor country with a democratic/non-aligned government and not in a faction, as well as allowing you to create your own faction. It makes sense to have it as a democratic focus, since Communists have their own ways to deal with factions.

06a Securing the Free World.png


I would also like to clarify the requirements for the following focuses:

Protect Chinese Civilians: Will grant a wargoal against the owner of Guangzhou, the state surrounding Macau. This focus is available by completing either The Popular Front Bloc, They Need our Help or Allow Free Elections.

Intervention in Spain: This focus grants a wargoal against Spain if their ideology does not match Portugal’s. It is available only through They Need our Help and Allow Free Elections.

06b Focus Requirements.png



Regarding the change of ideology, throughout the different political branches (be it Communist, Democratic, Fascist or even Monarchist) you will always find something like this:

07a CW main.png


As you can read in the lower red tooltip, if you attempt to change your government through the Focus Tree, you better make sure that stability is high enough, otherwise you could find yourself in the middle of a messy and unexpected Civil War (hmm… This sounds familiar to me…).

You will find something similar in the following focuses:

07b CW.png


07c CW.png


07d CW.png



Now let’s talk about the historical path (cool new icons in the branch courtesy of our freelance artist @Indyclone77, who also made all the Portuguese Focus and National Spirit icons, event pictures, and plenty of other 2D assets... Big kudos to him!). We have added a new sub-branch by which Salazar will slowly strengthen his regime, eventually turning Portugal into a powerful nation, capable of dealing with great powers late-game:

08 Historical Branch.png


The National Spirit Estado Novo represents the Salazar regime and has several levels now, being improved by different focuses along the branch.

You get it when you complete Estado Novo focus, providing a small bonus in consumer goods and civilian factory construction speed.

09a Estado Novo 1.png



Strengthen the Regime represents Salazar dealing with all kinds of dissidents (historically, Communists were specially persecuted and oppressed, but there were also other groups, such as fascist-syndicalists). You will have to invest some manpower and equipment to strengthen the secret police, but you will get some Non-Aligned support, and your Estado Novo will get small bonuses.

Upon completion of Appease Monarchists you will get the support of most monarchists and will unlock a couple of Monarchist-related advisors (shared with the Monarchist branch). Historically, Salazar’s strategy was to co-opt the Monarchy supporters into the government and leave the restoration of the Monarchy open for the future. Among other benefits, this focus will add a small daily PP and a weekly stability bonus to Estado Novo.

Concordat with the Holy See: The Concordat of 1940 was an agreement between Portugal and the Vatican, which basically prevented the Church from interfering in the political affairs of Portugal. In-game, you will get a nice amount of PP and Estado Novo will get a bit more daily PP and weekly stability.

National Gold Reserves: During the War, Portugal played an important economic role (it was more complex than the simple “they sold tungsten to Germany”, but I'll leave that for another day). In-game this focus will give Portugal a National Spirit with some economic bonuses, as well as better trade relations with Germany and the United Kingdom. Keep in mind: you have to be at peace to complete this focus!

By completing Honor Anglo-Portuguese Alliance Portugal will join the Allies, gaining access to the focuses shared with the Democratic Path.

Proudly Alone is the final focus improving Estado Novo and finally removing Unstable Republic. From here Portugal can choose to leave behind the historical approach and go into the offensive against Japan or any major or neighboring Communist nation.

09b Estado Novo 5.png



Last but not least, The Capital of Espionage focus: There were countless agents and plots in Lisbon during the war, from double agents and traitors who cooperated with former enemies to spies who gathered information on trans-Atlantic shipments for the Germans. This is represented in-game with the following National Spirit:

10 Spies.png



Regarding Refuse the Naval Blockade focus, it is now available not only through the Fascist path after National Syndicalism, but also through the Monarchist path after Return of Duarte. Now the Kingdom of Portugal can take revenge on the United Kingdom and finally connect its Angolan and Mozambican colonies (Mapa Cor-de-Rosa).

11 Refuse Naval Blockade.png



For those of you concerned about not seeing any custom tech sprites during the streaming a couple of weeks ago, I can confirm that there are Portuguese tech sprites, but unfortunately they were not hooked-in on the build we used for the streaming.

12 Tech Sprites.png



And that’s all from me, as you can see Portugal has gone through a lot of work during the last months and I hope you enjoy playing the different paths once the DLC is released!

For the next dev diary you won't have to wait a whole week as on Friday we will be showing off a bunch of stuff for modders as well as post the full 1.9 patchlog in preparation for La Résistance release next week.
Don't miss the stream today where we will continue our playthrough as Germany. Tonight we also have an AMA on reddit where you can pop in and ask us questions.
reddit_proof_iama_20200219.jpg
 
Last edited:
  • 2
Reactions:
Stop talking heresy about my Soviets. All that matters is red dawning of Germany. We found Hansel and his dead beat father. And I don't think they will be return to Berlin. Will make sure Gretel and her mother know knows slav. o_O
 
Did the issue of AI Japan sending many of their front-line troops on vacation every few weeks get addressed? Did tinker around with Manchukuo a lot recently and it is REALLY unnerving to regularly see large streams of troops boarding trains to Manchuria / Korea or even Ships to Japan while leaving the front severely undermanned, sometimes even leaving strips of the front completely undefended without apparent reason.

For reference:
https://forum.paradoxplaza.com/foru...-4-1-7-0-d12e-japan-shuffling-troops.1186777/
https://forum.paradoxplaza.com/foru...ng-units-from-china-front-1-7-1-87c8.1245372/
 
Oh ouch, that announcement is old info from before our feature complete gate. We experimented with battleplan changes but they caused a lot of issues so had to be scrapped for the time being. We have been working on some nice improvements to air management though, but they didnt make it in time for testing so I planned to add them for free in the big patch we usually do after release.
Could you say anything about what those air changes might be? For those of us modding in the air war area it could be very useful to have some idea - I already have data prepared for the armoured car changes, for example.

I think this is a nice suggestion with good flavor. I will consider changing the name for a future patch.

By the way, I believe those fortifications were mostly destroyed/abandoned after the Napoleonic wars (I will do some research here) and probably they wouldn't have been of much use for modern warfare... Anyways, it can be cool to have a reference to this fortification.
They are not completely gone - I walked around parts of them just a few years ago :) What remains would not be too useful in a WW2-era war, however (although some of the landscaping of hills could possibly be helpful - not many tanks can ascend a sheer-cut cliff that is 30 feet high or more until concentrated artillery has "breached" it...) - an appropriate name might be "The Lines of Torres Vedras Reborn!"
 
Yeah, the AI get an hughe improvement like some of the Gamers wanted. And some more Modding-Tools from the Devs incl. the AI-Test-Thing. Such improvements for a Game and for Modders I haven´t seen in the 30 Years I play Computer-Games (from C64 on and some other Consoles) and over 20 years on the PC.

I paused for Patch 1.9 and DLC La Ressistance my Hoi 4 Game as Germany, Australia, Japan and Dutch / Netherlands for the new Version which hopfully comes out Monday night 24:00 Hours.
 
We have also added some new ministers for nations. Having an Illusive Gentleman will be a good choice for those who want to go all in on making the strongest Agency possible:
View attachment 546551
You can also see that UK will get access to all programmers hero Alan Turing if they develop a cryptology department. He is more of a UK special though.
While I always like to see a nice (and appropriate) buff for the UK, I'd also be interested if you have included appropriate debuffs? As preparation for LaR (yeah, that's what it was - I would never have read it otherwise... ahem...) I read 'Hitler's British Traitors' by Tim Tate, which elucidates nicely some of the issues faced by any democracy with counterintelligence and the particular pecadilloes of the English class system of the time specifically. It also explains how MI5 got around them, in the end. I'd also recommend Paddy Ashdown's 'Nein!", which covers the anti-nazi activity inside the German state from 1933 onwards in some detail, including planned coups, assassinations (including a fascinating bit of background concerning the timing of Reinhard Heidrich's killing) and the activities of the Dora (Soviet) spy ring.
 
I think you should have inserted a second model that would have been colonial for the side called national as they did with Holland in MTG. Let's remember the colonial or Moroccan troops were one of the most representative troops of that side
 
Nice changes. Anything improving the AI is a win. Hoping one day we get some sort of division control/limit though. Seeing India having a 100 divisions, Mexico having 50+ and New Zealand who had 5 in the actual war pumping out 30 in my recent save sort of ruins any fun and authenticity, especially with supply.
 
I saw you guys introduce this tool a while back (I think MTG time) and was delighted you had something like it and where not manually running things etc.

I want to do some of my own spectate sessions with the new update and it's brilliant you have included it, I am looking forward to using it!
 
You can see tanks/planes etc in the Music and Art diary. Spanish infantry is a reskin to match one of the greeishn uniforms from the war. I am not an expert but spanish uniforms were extremely varied so we didnt want to get overly specific (and making a different one for every faction and sub faction was out of scope) Here is what it looks like:

View attachment 546813
So no Red Berets :(
 
The second thing is also related to Germany (its WW2 after all). For HOI (no matter the version really) we have always striven for a balance where Germany defeats the Soviet Union if the allies do not take pressure off by invading. This ensures that all of the big sides need to be active and if played by a player you need to step up. Now before we jump to the 10 pages of comments discussing if this is a realistic target... It is, for gameplay I think. History wise I am personally convinced that the Soviets would have beaten Germany on their own. It just would have taken a lot longer and been much costlier, and there isn't much point in playing the UK or USA if Soviets will just take care of Germany on their own (now now, please keep reading the rest of the diary before we start arguing what-ifs :p).

I really appreciate this explanation. It makes 100% sense. GJ team :)
 
I read 'Hitler's British Traitors' by Tim Tate, which elucidates nicely some of the issues faced by any democracy with counterintelligence and the particular pecadilloes of the English class system of the time specifically.
There was a mention in a dev diary some time ago that both democratic system and free trade make it easier for enemies to gather intel.
 
Okay, looking at the two simulations presented, it certainly seems that the AI has improved in regards to naval invasions and troop allocations in Europe at least, however Japan continues to dominate in the entire Pacific really, taking out China, India, Oceania and the entirety of SEA.
Ignoring China, they pretty much did conquer majority of Pacific including Burma. Japan AI being aggresive and dominating Pacific zone is exactly how their AI should always perform on historical:


1942 when Japan was at the height of its power.
 
Yep it was so too in the Versions now. I have played Australia for 3 or 4 Times and had the same picture as you show, before the Commonwealth States (Australia [me] and New Zealand) with the help from the Colonys from Denmark as well as British-Malaya and USA could push them back slowly.
 
Interesting observation regarding the age of the 13 people in the photo of HoI4 developers.

Assumption: The average age is 30.
Assumption: Each developer has been playing wargames since age 15

13 people x 15 years = 195 combined years of wargaming experience.
195 years of combined wargaming experience is a goodly number.

In today's "Ask Me Anything", Floh0815 asked the following question:

View attachment 546746

So what was the response?

As for your assumptions I highly doubt that the average age is 30 and I bet 5 or maybe more never played a wargame before they joined the company.

And the whole calculation is illogical. That's like saying a city of 1 million with an average age of 50 has more experience in urban development then a group of actual urban devlopers. Living or working for a comapany doesn't mean they are playing wargames. Some of their jobs could be accounting, or an administrative assistant and never played a wargame in their life.
 
History wise I am personally convinced that the Soviets would have beaten Germany on their own. It just would have taken a lot longer and been much costlier, and there isn't much point in playing the UK or USA if Soviets will just take care of Germany on their own (now now, please keep reading the rest of the diary before we start arguing what-ifs :p).

Just another point and I am all for what you are saying but unless the allies AI can beat Germany on its own some times, playing nations like China is pretty pointless on historical.
 
Last edited:
I have to say I am a little disappointed by the Spanish sprites, would have hoped for at least different skins for Nationalists and Republicans, if not for 5-7 different skins (African, Fascist, Monarchist, Nationalist, Anarchist, Communist, Republican)
 
You can see tanks/planes etc in the Music and Art diary. Spanish infantry is a reskin to match one of the greeishn uniforms from the war. I am not an expert but spanish uniforms were extremely varied so we didnt want to get overly specific (and making a different one for every faction and sub faction was out of scope) Here is what it looks like:

View attachment 546813

In true pdx fashion you need to announce a £4 content pack with art for portugal and 3d infantry sprites for iberia
 
  • 1
Reactions: