Hearts of Iron 4 announced


No crash for me. A strange visual bug in the research screen.

Despite 7 armored division from Germany, Japan was unable to conquer China by Aug 1939.
Poland and France both fell pretty quickly. The AI seem to fight reasonable well and France built a fair number of light tanks I captured 800+.


Those are very nice to convert to light SP-ART.


I haven’t had any EU4/HOI4 time since the recent updates. Do the AI improvements still seem to be holding up after your initial impressions? @MikeJ or @Strollen or anyone else that’s been actively playing?


Wait, what? You can convert tanks to another type?


It’s a feature in the latest DLC.


Holy crap that is amazing. It also gives me something to do with the thousands of light and medium tanks I accidentally overproduced.


Conversion works at I think 2x speed, but you can get two techs that add 40% to the speed. I’ve found it pretty sweet to convert Germany’s starting light tanks into something useful, plus all the stuff that gets captured. It also saves a lot of resources.

There are a bunch of different aspects.

I think the improvement to unit-shuffling at the front is definitely real. Given a good front-line, I think the units behave quite a bit better. However, adjacent front lines still have a tendency to bleed into each other, which still tends to lead to too much moving around if you don’t keep a handle on it (or just use one front line I guess…). Overall though I’ve had good success relying on the infantry to fill in behind my mobile forces. I wish the planning arrows and fronts were thinner and smaller at high zoom levels…

I haven’t seen big issues with front-abandonment, though I have seen a couple of cases where the AI seemed to be waiting for maximum planning bonus even if the opposition was extremely weak. Unit shuffling to Africa still exists, but is much less because it doesn’t send as many units to Africa. Actually, I kind of wish Italy would have sent more. The non-passable terrain is a very nice thing.

AI Germany still declares wars before the old ones are done, but in the one game where I was Canada, it seemed pretty competent at prosecuting those wars, though it was hard to tell from my perspective.

In terms of managing the economy, I think they have made significant improvements, though people are still pointing out some bone-headed moves. On this front, I can’t recommend the Expert AI 2.0 mod enough. I played Germany into 1940, thought I was doing very well, and then took a peak at what the USSR was building. I was scared enough that I decided to go back to 1936 and rethink my build strategy. This was with fairly minimal bonuses enabled.

So overall, it feels a lot better, though there are still some annoying things going on. It’s probably on the level of typical strategy AI performance. If they fix a few issues (like auto-war declarations, bleed-over of front lines, shipping through hostile waters, incorporating the Expert AI mod), then it would be ‘good’.


Hmm, have I mentioned in the last 24 hours how much I liked the production model in this game?

I find there are a lot of interesting decisions to be made in trying to get your country into fighting shape by a target date. Say you want to get high-tech tanks into the field by the time the war breaks out. Do you start out building some early tanks to build up gearing, and maybe convert them to SPG’s later?

If you want the tank built in numbers by mid-39, how early do you need the prototype to start ramping up to full production? Will your building program have delivered the free industrial capacity for mass production at this point? What about the all-critical tungsten?

The later you do the research, the more efficient it will be, involving fewer sacrifices in other areas. If the prototype needs to be delivered by say early-38, how late can you start the needed research? How late can you delay starting to negotiate the technical deal with the Russians to get the critical bonus to armor research? Keep in mind that the sooner you make the deal, the sooner THEY will have advanced tanks available for production, tanks that you will eventually need to fight. If you do the deal too early, you delay other political initiatives, and might end up with a tank design that you don’t have the factories to build.

Of course, you can’t just take a bunch of tanks from the stockpile in mid-39 and form up tank divisions. Well, you could, but they need time to train. For good competency, they need A LOT of time to train. Also they need equipment to train with, and you need to have enough land experience to bring your division designs up to date. Also let’s not neglect the infantry, their equipment, the doctrines, the air force and the navy. Well, maybe we will neglect the navy. Something has to give!

Overall, I think the whole set of game systems centered on the production model work out pretty well. It evolves fairly naturally over time, and you need to put some thought into what you are trying to achieve and when. It leads to a lot of natural conundrums.

The actual mechanics of unit balance, armor penetration, hitpoints and org is also very well done. It’s the diplomacy, the operational and strategic AI, some interface issues and some bugs that keep it from greatness.


I played German until 1940 and Japan until end of 38, Max help to the allies (I did boost Germany and Italy 1 notch in my Japan game)

I agree with Mike there are noticable improvements in a number of areas.As long as you keep the fronts fairly short the unit shuffling is reduced but not eliminated. I basically let the AI handle my front against the PRC and it played pretty well, with fairly minimal involvement The AI was quite good and shifting forces to where I was attacking but not over reinforcing.

The UK made a decent effort to defend the Suez and the Free French put up a strong fight in first capturing Vichy territory and the defending against the German counterattack. France fell quickly although it did last longer than the historical 6 weeks.

I attacked China as Japan as soon as possible May 36. I threw every unit I had at the Chinese. If I hadn’t succeeded in surrounded the force defending in the Beijing area, I don’t think I would have beat them. The AI actually recognized the danger and tried really hard to break out. I had a ring of cavalry south of the river near Beijing, the airport and Taijian (sp), My main force was pushing down from the NE, while the cavalry cut the supply lines and defended against vicious counteracts from PRC and other warlord forces. One of my cav units was down 10% strength. I played at speed 2, micro the hell out the attack and paused a few times. I was helluva of an exciting battle.

I conquered China on May 37 and while there were some places the AI let me walk into cities undefended, after losing 40+ division in the Battle for Beijing it just didn’t have the forces.

I turned my attention to Dutch East India (in addition to all the yummy oil, and rubber, Borneo now has 50 Aluminum (woot a whole line of Zero’s). It took 240 days for the war justification. When I invaded I got a nasty surprise. There were a moderate number of Dutch troops, making it not a cake walk. Then the bloody Russian sent 1/2 dozen armor division as volunteers who did a number on my Marines.

Other notes
I didn’t have a chance to use the conversion feature, not a lot of surplus tanks. I’m going go back to my Germany game and experiment.

The Air interface is a huge improvement. Way more intuitive and a lot fewer buttons to click and some nice information.

The AI manages its economy significantly better at the minimum they switch into the proper war economy.

The constant naval invasion by the Allies of NW Germany is still with us. Normally I have my troops in training garrison that area, but this game I add a full 24 division army and it didn’t deter the AI from launch wave after wave of invasions and generally dying on the beaches.

It’s nice to have different levels of puppets as the Axis

The Spanish Civil War last longer, it was still going on in 1938 in Japan game.

I’ll try the expert AI mod, but I think this game provides a very good single player experience for WWII buffs after this last patch.

Edit: I finally figured out how conversions worked and why I was confused. You can only convert Base models to TD or SP or new tank but not directly to a new varient. So if you wanted to convert a PZ III to PV IV E you need first convert the PZ III to a PZ IV. The convert the PZ IV to a Pz IV E. I generally spend experience points as soon as research is done on a new model so I wasn’t able to convert anything to it.


The battle for Beijing sounds amazing!

I thought you could convert PzIII to a PzIV SPG or TD, but not a PzIV tank. I thought conversion between tanks was only say PzIII A to PzIIIE.


You are exactly right, man I sure got confused.

It is a nice feature as well as being realistic. My idea of convert PZ III to PZ IV was just dumb. I can see using it a fair amount to convert Level 1 captured tanks to Marders and Wespe. Perhaps PZ III also.

It adds another level of depth to a what is already a terrific production system.
I seldom actually deploy level 1 Medium tanks, the level 2 being so much better. But saying you are training 3 medium panzer division at time you need 600-750 medium tanks for training purposes and PZ III work just fine in that role. But now you have another interesting choice, maybe I should building more PZ III so I can ramp up production of Medium II SPG quicker

Like Mike, I really love the production system. I like the production system better than even dedicated business games like Factorio or Capitalism II. As Rumsfeld said “As you know, you go to war with the Army you have. They’re not the Army you might want or wish to have at a later time. Building the army you want to go to war with, It is really a fascinatingly complex mix of R&D, resources, production capacity, and training. When it all works it is deeply satisfying, and now that the AI is generally pretty competent, the enemy gets a vote. Which fucks up your beautifully designed plans.

Anybody making a strategy game with production, would do well to steal liberally from HOI IV.


I agree, the production system is amazing. I think sometimes it’s hard for me to convey how cool it is to people who haven’t played the game. “You recommend the game because of its production system? I get that that’s an important part of war, but how fun/interesting can production be?”.


I absolutely love the production system, but it definitely feels that it was designed for the early game with not a lot of thought given to the late game. Managing production gets a bit rough by late war when you might have 5 or 6 full lines producing any given piece of equipment. It would be nice to have a mechanic to visualize that a bit more smoothly rather than having to scroll through 100+ entries on the production tab.


Yeah the UI doesn’t scale very nicely for a late-game major. It would be nice to be able to have an unlimited number of factories per line, and be able to combine and split off portions of a line while maintaining efficiency.


You guys are right the game doesn’t scale all that well But most of my games end by 41, and only a few go to 43, and only one has gone past 45. So I avoid the mess of the late war by restarting. :)

Speaking of restarting at MikeJ suggestion I’m trying out Expert A.I as Germany, I used the Dynamic system at the hard level it will be interesting to see how it works out. The war in China just started and I’m sending volunteers so this will be the first test of the AI.


I don’t think the mod touches the operational AI. AFAIK, it’s all about production and division design side. So I would expect the Chinese and Japanese armies to be marginally better equipped if the war drags on, but you would probably see the most difference later on against larger powers.

I am back up to 1940 in my Germany game, and to be honest, I haven’t seen amazingly-equipped enemy divisions so far. But then I hardly even fought the French, just kind of out-maneuvered them. I think they are doing better at building, but it’s hard to see that just yet without tag-switching. Right now I am contemplating trying a Sealion, though I don’t have any marines.


I’ve never found it necessary to use Marines to mount a Sealion-type invasion, unfortunately. I typically just hammer Edinburgh followed a month later by Plymouth. I do make sure I have total air superiority though, which usually means delaying Barbarossa by six months to a year.


I recently did a Sealion-type attack as Germany in the Kaiserreich mod. But that was after the Union of Britain had lost a lot of divisions in France, Italy and Sweden. I’m hoping that with the Expert AI changes, the UK will put up more of a fight.


Be sure to let us know how it goes. I haven’t played with Expert AI yet, but I would dearly love more of a challenge in the UK.


The usual post-release hotfix is currently available on the beta branch. Podcat goes over the details here.