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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.

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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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The argument is that the owner would have just destroyed or moved it if it got too close to the front, so it makes more sense to me to have the capture on capitulate like other stuff

I think it would lead to more interesting game play, and put more importance on capturing province's with fuel silo's (and also having to defend them if your going to loose a portion of that silo's fuel) especially countries that would be short on fuel.

Maybe even if you where too capture a certain proportion of the silo's fuel.
 
Different topic:
Also whats up with the SA nerf last patch?
Do you have statistics how this has has influenced the game? If you have these can you publish them please?

Nerf of base SA was needed, otherwise you would get ultra silly values of Soft Attack.

And tbh SA is not nerfed in the end.
 
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Being able to capture some of the fuel when taking over a storage building could lead to some cool historical stuff like battle of the bulge where your Panzers don't got enough fuel to reach the objectives but there are fuel you can capture on the way.

I think both approaches could have some merits worth considering.

If all buildings were gradually damaged by combat instead of just infrastructure it would also work to have you capture a portion based on it's damage so drawn out battles see most of the fuel destroyed before capture.

In terms of tactical/operational capturing of fuel, it's kind of second-hand, one-party removed, but when I was reading Oil: A Study of Wartime Policy and Administration it made a point of noting that Britain changed the way it stockpiled its fuel in the South-East of England to prevent Germany being able to take advantage of stocks, like it had when it had invaded France. At least in the British case, there was always a tension between having fuel kept close enough to the front and spread out enough to respond in good time to needs, and more secure but less accessible locations (so, and this is going from memory, but I think I remember it right - the British kind of accepted that a little bit would still get captured, but worked hard to minimise it so it wouldn't be enough to cause trouble).
 
Will this neat addition make you give Bessarabia the strategical significance it had in WW2?
The Soviet Union seized it because of the Oil Fields there, those were vital for them, as well as for Germany. That's why Hitler was so keen in retaking it as fast as possible.
Sadly right now Bessarabia holds no Oil as ressource.

Maybe considering giving it a nice big Oil-boost to make it really an important decision to secure it as either sides of the war :)?
 
Will this neat addition make you give Bessarabia the strategical significance it had in WW2?
The Soviet Union seized it because of the Oil Fields there, those were vital for them, as well as for Germany. That's why Hitler was so keen in retaking it as fast as possible.
Sadly right now Bessarabia holds no Oil as ressource.

Maybe considering giving it a nice big Oil-boost to make it really an important decision to secure it as either sides of the war :)?
As far as I know, the only thing strategic about Bessarabia in HOI4 is that is means one more river to cross.
 
I think it is pretty clear from the DD that both of those already exist. Capturing a state which contains a silo is one obvious example but probably not the only one.

And what did you think all that gobbledygook about number of states and infrastructure level etc. etc. was at the beginning? That was clearly allowing (in an abstract manner requiring no micro) how much of your oil was being used by the civilian economy.
Ye but I am pretty sure he said that you get no oil immidietly for capturing province with silo only on surrender do you get the fuel, which is fine.
As for the second part thanks for clarifying I didnot see that.
 
Being able to capture some of the fuel when taking over a storage building could lead to some cool historical stuff like battle of the bulge where your Panzers don't got enough fuel to reach the objectives but there are fuel you can capture on the way.

I think both approaches could have some merits worth considering.

If all buildings were gradually damaged by combat instead of just infrastructure it would also work to have you capture a portion based on it's damage so drawn out battles see most of the fuel destroyed before capture.

I think, issue here that game doesn't actually store fuel in buildings, they just define cap. So you don't know which building is empty and which is full.
 
Will this neat addition make you give Bessarabia the strategical significance it had in WW2?
The Soviet Union seized it because of the Oil Fields there, those were vital for them, as well as for Germany. That's why Hitler was so keen in retaking it as fast as possible.
Sadly right now Bessarabia holds no Oil as ressource.

Maybe considering giving it a nice big Oil-boost to make it really an important decision to secure it as either sides of the war :)?
Can you give a source I am looking into ussr occupation of that area in 1940 but no where it talks about oil fields thank you.
 
I think, issue here that game doesn't actually store fuel in buildings, they just define cap. So you don't know which building is empty and which is full.

Yeah, I agree. But it still might be possible to use an average value.

For example if you would capture say 50% of remaining fuel in a building and a nation have 50% of their stockpile full you would capture 25% of the full capacity of a building when taking it. ( Basically assume it's evenly distributed ).

I have no idea how much extra work it would be to code though.
 
In addition to fuel you could introduce grain/food/field ration which could be stockpiled. This could limit the amount of infantry spamed out, just like fuel limits the number of tanks
 
In addition to fuel you could introduce grain/food/field ration which could be stockpiled. This could limit the amount of infantry spamed out, just like fuel limits the number of tanks

How many real WW2 countries were limited in the forces they could field or had to disband divisions based on by how much food they could produce?

None as far as I am aware. ( Maybe nations like India and China? I don't know ).
 
How many real WW2 countries were limited in the forces they could field by how much food they could produce?

None as far as I am aware. ( Maybe nations like India and China? I don't know ).
I think it was quite a challenge in China. but from what I gather its the kind of thing that has a lot less impact on the armed forces. So you'd potentially have civilian grumbling and revolts, but not surrendering soldiers.
 
In addition to fuel you could introduce grain/food/field ration which could be stockpiled. This could limit the amount of infantry spamed out, just like fuel limits the number of tanks
if you want to try that kind of thing there is a mod called the Resource War on the workshop that adds food and such.
 
Nerf of base SA was needed, otherwise you would get ultra silly values of Soft Attack.

And tbh SA is not nerfed in the end.

I do not say a SA nerf wasnt needed but I cant ignore that it was too much.
With the current system all you do is: Mass Assault 10w Inf, Fighter and CAS spam and it is super effective.
Entrenchment wasnt touched, we have ridiculous boni on entrechmentspeed, entrenchment, division defense in combat and infantry (look at da generals) and now we have a WW1 simulator where tanks can get stalled easily and all you really need to produce to be effective:
Some trucks, guns, supportequipment, fighters and close air support and tns of manpower. Maybe some Strats too if you want to damage the enmies infrastructure and buildings when they are not banned.

Therefore I like to see statistics about the game which compare prenerf and nerf.
 
@podcat

What happens to regiments that has "tank/truck/etc..." and infantry and horse whose fuel has ran out? Will the lack of fuel completely stall infantry/horse?

Edited: Nevermind already answered. Will move very slowly.
 
I think it was quite a challenge in China. but from what I gather its the kind of thing that has a lot less impact on the armed forces. So you'd potentially have civilian grumbling and revolts, but not surrendering soldiers.

Yes I agree. I think it would be better to add some sort of maintenance cost for large forces to limit the numbers both in peacetime and in war. Like existed in HoI2 and HoI3 where supply costed industry to produce.

IRL having a massive Army, Airforce and Navy was a big cost that limited how much new units that could be fielded.
 
I do not say a SA nerf wasnt needed but I cant ignore that it was too much.
With the current system all you do is: Mass Assault 10w Inf, Fighter and CAS spam and it is super effective.
Entrenchment wasnt touched, we have ridiculous boni on entrechmentspeed, entrenchment, division defense in combat and infantry (look at da generals) and now we have a WW1 simulator where tanks can get stalled easily and all you really need to produce to be effective:
Some trucks, guns, supportequipment, fighters and close air support and tns of manpower. Maybe some Strats too if you want to damage the enmies infrastructure and buildings when they are not banned.

Therefore I like to see statistics about the game which compare prenerf and nerf.

If you play in Multiplayer and build neither tanks nor AT weapons that can counter them you will lose any war that's not fought in mountains or rivers/forts.

In my last MP game in 1.5 we inflicted 10 million casualties on the Soviet despite them following exactly this strategy above, mainly by using divisions with Tanks / SPGs / SPAA. In some key battles we defeated over 50 Soviet divisions before winning ( with same tanks that started the battle ), since the infantry was unable to inflict damage to the tanks, and since SPAA now reduce damage they take from air.
 
Not in real, but use the idea as an abstract. During war Germany e.g. was very limited in foodsupply. The population had to suffer from hunger cause nearly no one was interested in trade any longer and the domestic production wasn´t able to compensate the loss of trade. If the german staff would have conscripted more farmers, the foodsupply would have collapsed completely. So in my mind the idea of introducing food as a limiting factor seems valid.
 
I do not say a SA nerf wasnt needed but I cant ignore that it was too much.
With the current system all you do is: Mass Assault 10w Inf, Fighter and CAS spam and it is super effective.
Entrenchment wasnt touched, we have ridiculous boni on entrechmentspeed, entrenchment, division defense in combat and infantry (look at da generals) and now we have a WW1 simulator where tanks can get stalled easily and all you really need to produce to be effective:
Some trucks, guns, supportequipment, fighters and close air support and tns of manpower. Maybe some Strats too if you want to damage the enmies infrastructure and buildings when they are not banned.

Therefore I like to see statistics about the game which compare prenerf and nerf.

Notice how I said that 'base SA was nerfed' - end result of SA is quite often higher than it used to be (Panzer Divisions usually will end up with more SA than they used, DESPITE base nerf of SA to some of it's components). People will often hear 'trench simulator' and instead of looking at the bigger picture/adapting to the changes they repeat with what they've just heard.
 
Not in real, but use the idea as an abstract. During war Germany e.g. was very limited in foodsupply. The population had to suffer from hunger cause nearly no one was interested in trade any longer and the domestic production wasn´t able to compensate the loss of trade. If the german staff would have conscripted more farmers, the foodsupply would have collapsed completely. So in my mind the idea of introducing food as a limiting factor seems valid.

Podcat mentioned a mod on the workshop which adds this, sadly no achievments which is one reason why it should be part of main-game, but then, is it a priority of development right now? Either way, here's podcats response.

if you want to try that kind of thing there is a mod called the Resource War on the workshop that adds food and such.