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HOI4 Dev Diary - Fuel

Hi everyone! We have now been working on Man the Guns for a bit and it is time to kick off dev diaries again!

For those who missed it, Man the Guns is the expansion we are currently working on. The main theme is naval warfare and it will be accompanied by the 1.6 ‘Ironclad’ free update. There is no release date yet. We will let you know when we can commit to a date :)
So without further ado, rev up your engines! Today we are going to be talking about fuel...

Fuel is something we originally decided to abstract into the production of vehicles in HOI4. The reasons for this were twofold: It simplified things, making the game easier to get into and learn and it avoided issues with fuel stockpiling in HOI3 (I’ll get to that later). I still think these were worthwhile tradeoffs with the gameplay impacts it had, but some areas, particularly naval warfare, never felt right without an overall worry over a supply for fuel, which essentially drove Japanese war planning historically. This in combination with a feeling that our fans can for sure handle a little nudge towards complexity now kinda cemented the idea that we couldn’t really make a naval expansion without expanding on this area.

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(no numbers are final etc ;))

Land
Fuel is used by trucks, tanks and other land equipment with engines in your divisions. They will use much more when fighting and moving than when stationary or during strategic redeployment (in fact right now those consume no fuel, but that might change with balance work). A division carries a bit of fuel with it ( much like how supply works), so there is a short grace period if cut off. If a division is in bad supply it will refill its fuel more slowly (meaning you won’t be able to attack or move rapidly as frequently), and you might even be unable to refill at all if totally cut off. Being without fuel will negatively affect the stats of the battalions that need it as well as severely impact speed depending on how low they are.
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Air
Your active air wings will consume fuel. The amount will naturally depend on the type of plane (strat bombers love to guzzle down that fuel) but also what mission type. Planes on interception will be very fuel efficient as they only take off when there are enemies attacking ground targets or bombing etc. Transport planes on air supply missions will also be able to deliver fuel to pockets etc. When low on fuel air wings suffer big efficiency penalties.

Sea
Running a lot of active capital ships is something you will need to be careful with in Man the Guns. These behemoths will be going through your fuel stockpile like starved baby whales on the teat. To handle this and make fleets act more realistically and in a more controlled manner we have changed quite a bit here, so stay tuned for future diaries. The main point is that big fleets are costly to run and you will need to make decisions on how to best utilize them and how much to fit into the rest of your fuel use. Speaking of, you’ll be able to control who gets first dibs on fuel through prioritization just like with equipment (but we are also working on adding extra controls on top of this so you can more easily balance between the different branches of the armed forces). A fleet that is low on fuel will suffer penalties to its stats as well as operational range.


Production
Fuel is produced from unused oil, and equipment that used to use oil now no longer need that to be produced. I am currently looking into possibly adding copper or another resource in its place (and in some other places), but we will see if that ends up being a good idea or not ;) Will let you know. Anyways, if you are low on fuel there are several ways to go:
  • Acquire more oil rich states.
  • Increase infrastructure on your own oil rich states.
  • Trade for foreign oil.
  • Build synthetic refineries.
  • Lend leased fuel.
  • Capture enemy stockpiles.
  • Research improved oil to fuel conversion technologies.
  • Each unit of oil you have access to use your current techs to generate a certain amount of fuel. This fuel is then put into your stockpile for use by your forces.
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Stockpiling
Fuel is possible to stockpile, in fact it is necessary if you can’t guarantee a steady stream of produced fuel during wartime. The size of your national stockpile will depend on the number of states and their infrastructure, your economic law and if you have built Fuel Silos. This is a new building that takes up shared slots and will probably provide the majority of your stockpile space. It is also a building that can be damaged from bombing etc. which in the worst case could lead to a loss of fuel. Capitulating enemy neighbors is also going to be a good way of acquiring more fuel as it will work just like seizing their equipment stockpile in that respect.

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HOI3 also had stockpilable fuel, and there it was quite a problem. As a beginner you did not know how much (or even that you had to) stockpile and as an experienced player there was no issue in making a stockpile big enough that you wouldn't ever have to worry. In HoI4 we are aiming to force a tradeoff between building up your industry and increasing the stockpile (have to spend civilian factories to get more oil from trade instead of building more factories) as well as trying to keep the total amount you can stockpile within reasonable bounds. Our goal is fuel as something you’ll need to consider for all your operations and playing it really safe will mean less industrial output in the long run.

Since I bet this will be the first question, fuel is going to be in the free update, but there will of course be features in the paid expansion that tie into it (stay tuned for more diaries!).

We are still working on all things fuel so I’ll wrap up here. Hopefully it gave you an idea of what we have done and are planning to do. I’ve saved some interfaces talk for future diaries, and also, be aware that many things could end up changing based on gameplay feedback. Rest assured though, I’ll keep you updated on stuff like that in these diaries up to release. This is not really anything out of the ordinary, but I usually keep systems like this that need long term balance and iteration for later. Fuel however ties into a lot of future topics, so I wanna make sure you are all clued in :)

Now for something completely different...
I assume nobody has managed to avoid having their mailbox fill up with fun updated privacy policies and things related to the new European General Data Protection Regulations (GDPR). During all this a really smooth looking lawyer dog in the smartest little suit I have ever seen came over to visit us from Brussels. He told us there are a bunch of regulations we too need to follow in our games… so to make sure we remained Good Boys in the eyes of the law we have added a couple of things to Hearts of Iron IV. The most important is to include our Privacy Policy in the game and making it easy to find.
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Legal texts are long and boring and nothing has really changed in how we do things. So I would rather spend my time answering questions here and writing the rest of the diary, so I will refer you to check it out ingame or here if you want to.

What I would rather talk about is how gathering data from players is useful to us. Because it is. Super useful! Without telemetry we would be resorting to guesses and risk only the most vocal minorities to be heard. For example, telemetry data is one of the major things we look at for deciding what nations to develop focus trees on. We get data on how popular difference choices are for focuses, letting us spot balance issues or unpopular paths that could use some love and care. We can spot if new out of sync errors are introduced in multiplayer in graphs and get crash reports automatically uploaded to help us fix problems easily. All this, combined with a scoopful of forum reading, is what helps us steer this ship, so thanks for helping :)

Oh I almost forgot, because we had to make the GDPR compliance hotfix we managed to sneak in a fix you guys have been asking for. We solved an issue for a case in China (similar things could also happen elsewhere) when a nation had both a takeover and inherited wars (like when seizing ownership in the Chinese power struggle) and was at the same time occupied. As a Japanese player this would lead to the less than happy situation of seeing your occupied areas flip back to the enemy and leaving troops cut off from supply. We also fixed a crash issue that was reported in some big mods. The patch should be releasing shortly.

Next week some of the team will be on summer vacation (including me!) but Bratyn is going to be here to talk about all the awesome stuff he has been doing with Britain, so don't forget to tune in!

  • Fuel for Thought
  • The Rise of Legal Pooch: GDPR always strike twice!
  • How we sell your personal data to Big Pharma for cocaine in 3 easy steps!
  • We have updated our fuel policy
  • Starved Baby Whales on the Teat is actually the name of the HoI 4 punk rock band playing at PDXCON 2019
  • Fuelling your conquests
  • Some of your data is belong to us, if you are okay with that
  • Help us help you help us
  • Our coders call it Nightmare Fuel actually
  • Adding fuel to the fire that engulfs the world
  • Anyone doing a dramatic reading of our privacy policy may request one Admiral to be added to the game
  • Proudly Introducing Gasoline Mana
 
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My idea with food is that farms could also be used in trade, like civilian factories. Food production would also affect population and stability, as food shortages caused a lot of problems for the Germans and Russian alike.

Rations and ammo would be consumed like support equipment, and consumed at higher rates while troops are in combat. Like with oil, players would be able to decide whether the army or civilian population gets priority for food distribution, and damaging infrastructure would hurt this.

I'd also change economy laws to make civilian economy desirable. Civilian economy would now give bonuses to farms, civilian factories, and dockyards, while giving penalties to military factories, refineries, and infrastructure. Civilian economy would also require 80% of nitrogen production to go to farms.
 
The problem of having farms in the game as strategical assets would mean we can bomb them and if tied in a way to stability, one could interpret this as 'starving out' a country, which is a no-go area according to forum rules (see: war atrocities).
However, I might see the need for having a kind of consumable to maintain armed forces like having fuel for ships and tanks. Abstracted 'supply' resource producible by civilian factories or by other mechanisms and storeable in depots would abstract and represent rations, medical supplies and ammunition so basically everything, the unit will need while idle or in combat. While in combat or training these numbers would be high, while idle these would be low but be needed. Lack of supplies could lead to attrition (deserting soldiers or at least not combat-able because of voiceable and unspeakable reasons). The problem is: how to produce these supplies? MIL seems the wrong way. CIV would slow down the game as building times rise and minors are bound to be helpless. So I can see the need for farms somehow - or something similar.

I hope, I would not make this too complicated, but what if CIV factories really could do only one of the following: to build, to produce consumer goods and to produce supplies. You have an incentive to keep CIV in wartime and not to convert everything into MIL.
Consumer goods are required by economy laws and population and you should have the means to make them to uphold or improve stability - we have the toasters already nowadays - some CIV stripped from your pool to sustain your people. Surplus of toasters could be traded like other strategic resources. See the CIV factory as doing something similar to the refinery. It produces strategic resources that are needed by your people and are exported according to market laws. And now the novum: you can allocate CIV to produce supplies. It would need the strategic resource 'produce' which will plop up almost everywhere in plains or hills, less in urban regions and even lesser in deserts or mountains with none in arctic. So usually, you have them and can trade surplus and improving infrastructure will improve these as well. Also, you might add need for steel as some items are metallic and maybe - if you want to go really crazy: chemicals (like ammonia which is also needed for rocket fuel and ammo) made by chemical plants (work like refineries). Those factories will fill up a bar similar to the fuel one and instead of fuel depots you might need military depots and good infrastructure to save more of those. This will really change the pre-war metagame.
The bad thing: more country development sim - and this is not everybody's cup of tea. A good suggestion to collect LOTS of 'politely disagrees'...
The good thing: more immersive and logical - and it gives agrarian countries something to trade.
 
Maybe farms could produce 'snivel gear' from organic materials (cloth, food, medicines, etc.), while 'support equipment' is produced from metals?

I'd also want farms to be connected somehow to population growth. Agrarian cultures are usually quite fertile and religious.
 
I wonder, what would be if building factories would on the other hand, reduce the produce a province supplies - that means the more industrializing a country is, the bigger the need for produce for several reasons: producing consumer goods and making rations while having even less means to do so. Like an undeveloped landslot would actually do something, if you leave it as is - make 'produce' or fractions of it, if unsuitable area like deserts only making 1/10 of it while fertile plains do it at a 1/1 ratio. Unfortunately, the latter will have the most building slots. So basically, you are penalized a bit if you plaster everything with CIV and MIL but have trade tokens if you refrain from doing so.
 
In that case, I'd have civilian factories on upkeep, just like how ships have separate tabs for dockyards for building vs repairing. Infrastructure, especially, would need lots of upkeep in high-traffic areas. Extreme temperatures, flooding, and other natural phenomena would further add to the demand.