Hearts of Iron IV - Developer Diary 16 - World Tension

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Game Director <unannounced>
Paradox Staff
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Jul 23, 2007
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Hi everyone, it’s time for another dev diary! Today is also Victory Day, the date that marked the end of World War II in Europe with Germany’s surrender in 1945. The team will celebrate by playing some HOI4 multiplayer, but for the rest of you here is the diary!

To start off, we have made some changes to previously presented stuff. When we last talked about parties and ideologies there were only 3 ideological leanings for countries: Democratic, Fascist and Communist. After some playing we felt this was too constraining, so we have added a 4th group we call Neutral. It functions as a sort of catch-all ideology for nations who don't really fit into the big three. Nations like Poland, Greece, or Yugoslavia fit here, for example, instead of lumping them into the ideology we expect them to join. Neutral nations, for the most part just want to be left alone to get on with life, but their lack of a solid stance means that members of the main ideologies have an easier time influencing them.

Neutral nations have some limitations and special rules, they won’t be able to promote their ideology in other nations like communists and the others (more about that in a future diary) and they are more easily affected by outside interference trying to push them towards another ideology. When it comes to freedom for you as a player to do aggressive actions abroad they are somewhere between democracies and fascist dictatorships.

This takes us to the next topic: World Tension. This is a new concept in HOI4 and is designed to replace the threat and neutrality system from HOI3. World tension is a global value in the game and is raised whenever aggressive actions are performed. How much is affected by the nature of the action and the size of the nations involved. Say a diplomatic annexation of the sudetenland will generate a lot less tension than an unjustified declaration of war and a war settled with minor border changes rather than total occupation and annexation will likewise generate less tension. Speaking of unjustified declaration of war a nation in HOI4 will need a reason to go to attack someone. Even if it's just justifying the war to the local population and nobody else is really buying your arguments. War justifications can either be given through special National Focuses or be generated through normal gameplay. The time and tension impact to generate these depends on the country’s ideology, and if they have some kind of legit reason, like foreign controlled core territory or claims.


World Tension works as a limiter on certain actions, depending on your country’s setup and ideology. So a nation like USA, which has special internal country circumstances modeled as well to make entry into a world war harder requires something like 100% tension to join a faction. To compare a non-aligned nations like Poland need only a 40% world tension to be able to join factions. Like the USA there are also other nations who have embraced a policy of neutrality or isolationism, like Sweden or Switzerland, these nations generally need to work through chains of National Focuses to remove these limitations.


For fascist expansionist powers World Tension is your enemy. You'll want to make sure you time your actions so that it doesn’t bring tension over limits where democracies are free to move in and stop you and let the tension decay, of course being a global value there may be other forces at work in the world so being able to do a diplomatic limbo dance might be harder than it sounds and you might find that stuff heats up a lot faster than you are prepared for. World Tension is also something that can be bypassed through special treaties and such set up through National Focuses, but these are generally country specific solutions and we will look at those in more detail when we cover each nation’s Focus choices.

I'll see you in a month with the next diary, and after that you should be seeing weekly dev diaries leading up to release!
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imho, military aspects of the game should be highly detailed
the rest should be simple
so, it think this feature is not very essential and needed
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Looks really great. I just love the graphics and the cool stuff you put in the game. The world tension system sounds to be pretty fun!!! What i really love here, is that you need to keep an eye on everything and that your actions provoke counterreactions. And off course you need to gamble a bit, as you don't know, what countries like russia or gb choose as national focus...all in all: very awesome dd!!!
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Looks great!
I'm shamefully bumping a question from last months DD;

Sorry for the total unrelated question :oops:
What unites will be represented in-game with 3D models?
So far we have seen, infantry, tanks, fighters, bombers, convoys, "battle" ships, carriers and subs.
What about artillery, personnel carrier, trucks and cavalry troops etc.?
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I like the way this mechanic works. This is going to be superb when it's done. :)

Here, have some fitting music from The World at War, makes dev diaries 500% more epic to read:

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imho, military aspects of the game should be highly detailed
the rest should be simple
so, it think this feature is not very essential and needed

I wouldn't go so far. I like the world tension, but I can agree with you, that there're at least 100 issues of HOI IV I'm more interested in;)

But I think that this other topics are highly under investigation, so they concentrate more on presenting the simpler topics right now and working hard on the essential ones:D
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