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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.
Screenshot_2.jpg


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.

upload_2018-6-27_11-41-38.png


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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I think this is very silly.

"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."

Probably the worst way to do the system. Better would be just to increase fuel consumption the more factories you have. Germany had huge problems with it's industry as the rationing was so tight, one example being that they couldn't test fuel pumps because there was no fuel.
Tying it to number of states and their infrastructure and fuel silos especially make no sense. Better option would be to just have everything guzzling fuel all the time, and you controlling the rate it's consumed as I said above.

I think you are misunderstanding. This isnt about consumption or production, just storage space. The idea is that decently developed states will have some kind of room to store fuel even if you dont build silos. It means small nations can store a bit without needing expensive buildings etc
 
@podcat - Just to clarify, if there's literally no fuel left can we we assume that no vehicles can operate? Or do they just suffer a reduction in efficiency/combat stats?
Right now its a 90% penalty to stats if I recall if you are completely out. and more to speed. if we made them unable to move certain situations would be too horrible
 
While the addition of fuel is good and overall seems to be far superior to what have been seen in previous HOI games I worry about that addition of fuel will create new problems such as infantry spamming because divisions have no resource upkeep.

Maybe you could use the same idea as with fuel silo and add Another building which cap the amount of allowed divisions or something to stop massive amount of division spamming everyone does?

We want to have some mechanic to control army size more directly, but that is a more complex design problem than might immediately obvious.
 
Will Land Doctrines change anything about fuel efficiency/consumption like "Mass Motorization" in the Mobile Warfare doctrine?

Logically that one should cause the infantry to require fuel to work, no?
 
We want to have some mechanic to control army size more directly, but that is a more complex design problem than might immediately obvious.
It is good to know that it is looked at because it can get pretty serious as the game progress into the late game when everyone have massive armies.

How will the ai be able to handle fuel?
 
(in fact right now those consume no fuel, but that might change with balance work)

I recall in HoI2 & 3 stationary tanks & mechanised still used a little bit of oil/fuel.

Transport planes on air supply missions will also be able to deliver fuel to pockets etc.

I hope TP planes still also use fuel themselves.

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.

Hopefully there's some level of automation added to this, e.g. allowing to automate rotation of designated ships in and out of fleets. Otherwise it's going to be a micro-hell that will be very annoying in multiplayer where you can't pause the game.

copper or another resource in its place (and in some other places)

Finland was the #1 supplier of nickel to Germany from 1940 to 1944 (IIRC ~90% of Germany's nickel came from Finland by 1944). Without nickel you can't make shells, engines for prop-pitch aircraft, etc. Finland also produced copper. Perhaps the Kolosjoki nickel and copper mines in Petsamo can finally get some love from PDX, that'd be awesome.
 
Sounds like a great and well thought out addition.

Now of course as an avid modder, my thoughts immediately went to "can we mod in our own new stockpile-able and consumable resources?"
 
While the addition of fuel is good and overall seems to be far superior to what have been seen in previous HOI games I worry about that addition of fuel will create new problems such as infantry spamming because divisions have no resource upkeep.

Maybe you could use the same idea as with fuel silo and add Another building which cap the amount of allowed divisions or something to stop massive amount of division spamming everyone does?
Perhaps armory and gun storage?
 
Finland was the #1 supplier of nickel to Germany from 1940 to 1944 (IIRC ~90% of Germany's nickel came from Finland by 1944). Without nickel you can't make shells, engines for prop-pitch aircraft, etc. Finland also produced copper. Perhaps the Kolosjoki nickel and copper mines in Petsamo can finally get some love from PDX, that'd be awesome.
I think nickel production is represented by either Chromium or Tungsten right now. In fact "steel" is produced in places that historically only really had iron and copper mines.