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HOI4 Dev Diary - Amphibious Vehicles and Research

Hi everyone! Another wednesday means its diary time! Today we will be talking about some quite big balance changes to tech as well as some new... watery toys :)

Amphibious Armored Vehicles

With Man the Guns we are adding two new classes of vehicles. Amphibious Tractors (AMTRACs) and Amphibious Tanks. AMTRACs were built in large quantities and used both in the Pacific by US Marines with good success as well as in Europe during major river crossings such as the Allied crossing of the Rhine. An AMTRAC is a amphibious tracked vehicle that offers soldiers protection, and depending on model, firepower when conducting landings.

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For heavier armor and firepower, amphibious tanks were developed. The allies used quite a lot of the Duplex Drive Shermans during D-Day. The idea was that the tanks would swim to the beach, then drive on to assault the German fortifications. The Sherman DD itself had some design problems, as it was designed for only 30cm high waves… which aren't exactly rare at sea. Many of them were also unloaded from their landing ships much too far out and sunk in the waves. Some beaches had good results, but for example Omaha beach was a disaster where most of them were lost. The Germans also planned for tanks for Operation Sealion, but experimented with snorkels and driving along the bottom instead. These were instead used during Barbarossa. The Japanese went more in the direction of attachable “flotation parts” with the Ka-Mi and Ka-chi tanks, making them look like tiny little warships. They never got the same large scale testings as the American tanks, but to me at least, seem to have been a more reasonable technical solution.

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These things combined means that you can design divisions to punch through heavily defended landing sites. Quite useful late game! These divisions are also great for when the enemy has fortified across a large river. On the flip side they are quite expensive to make, less fuel efficient and a little slower for what you get so you should have some plan for them before investing. Amphibious vehicle battalions also use your special forces limit, just like marines.

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Man the Guns comes with 10 unique 3d models for the amphibious tanks:
mtg_amphibious_eng_sov.png

mtg_amphibious_ger.png

mtg_amphibious_usa_generic.png

mtg_amphibious_jap.png


The mechanized infantry AMTRACs can be found in the Infantry tech tab while the Amphibious tanks are a branch of light tanks (the tier 2 amphibious tanks are close in stats to the 1939 medium tanks):

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Research Changes
We are changing up some things when it comes to technologies as well. Because we have been steadily adding more, and are adding a bunch more with Man the Guns, we will be adjusting the base research speed to be faster. Probably something like +10%, but we haven’t locked that down yet.

We are also changing how the formula works for calculating how long it takes to research things. Instead of a research bonus lowering the cost of the research, bonuses now affect the speed of research. This means that an old -50% cost modifier is roughly the same as a +100% speed modifier now. I say roughly because speed modifiers stack a lot better and in less odd ways when there are many of them. This essentially means that you can no longer get instant techs by stacking various modifiers, just really fast research.

We have also changed how ahead of time works and the Ahead of Time Bonuses from focuses etc. no longer give you a percentage off, but a number of years off. This is important because it makes certain tech rush strategies where you simply bypass much of the tree by chaining ahead of time bonuses not work. We feel that these things will make things play a lot saner, and stop ahead of time researching to be banned in some MP groups ;)
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The other change we are doing is to allow certain techs to get a bonus from XP. All doctrines as well as certain modules like torpedoes get a research boost when spending XP on them. This does two things for us: On the one hand we are not happy that one of your research slots is basically always locked to land doctrine research, and also the fact that we don’t really want nations to have maxed out their doctrines by the start of the war. So doctrines now get a bit slower to research, but by spending XP (benefitting the nations we want to have an edge here, like the axis) you will be researching faster than before. The other thing is to model certain stuff that were notoriously hard to get working right, like torpedoes, which for some periods of time had something like a majority failing to actually detonate when hitting a target. We want nations who get to see action here or dedicate training time on it to have a bit more of an edge.
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That’s it for this time! Do not miss that we are starting streaming of Man the Guns gameplay today, so tune in to see the new USA tree at 16:00 CET at https://www.twitch.tv/paradoxinteractive
 
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Just wish Helicopters would be added... No matter they become an air wing, a battalion, or used as they were in HOI3. Still, great stuff
I am afraid that during WWII there were only few prototypes. First conflict, where they were really used, was Korean war and at the time only for transport of people and equipment.
 
why don't you turn experience points into the three powers from eu4.
you spend a bunch of them to unlock doctrines. and doctrines don't take up research time anymore.

in late game it feels like experience points are pretty much free, with all the gunfights going on all around the world. you feel compelled to improve your tanks mainly just not to waste any of them. you end up using a lot of time just having a number of mark X tanks and changing your production lines. which should really be taken care from technology anyway.
 
Agree 100%, but I wonder if they're reluctant to do it this way because it would require them to make a new amphibious model for every single tank.
I don't think that would be necessary from day 1 - just set up the amphibious tanks that are already intended as subtechs and let modders do the rest. The additional models casn always be added later, as time for research, art, scripting, etc. allows. Basically, always build for future growth :)
 
why don't you turn experience points into the three powers from eu4.
you spend a bunch of them to unlock doctrines. and doctrines don't take up research time anymore.

in late game it feels like experience points are pretty much free, with all the gunfights going on all around the world. you feel compelled to improve your tanks mainly just not to waste any of them. you end up using a lot of time just having a number of mark X tanks and changing your production lines. which should really be taken care from technology anyway.

I understand what your saying but developing strategies and doctrines still takes time in reality, and the likely XP cost would basically leave any nation that wasn't fascist, communist or the size of the US or bigger stuck on the first rung of the doctrine ladder, with an guaranteed inferior army than any larger aggressor. And if the XP cost was reduced, you would likely still have this issue, as the larger nations with the right ideology could practically fly through the whole doctrine tree relatively quickly.

I agree there needs to be more stuff to spend the various XP's on but making doctrines only purchasable by XP would pretty much force most nations to pour all their XP into doctrine research. Maybe some XP cost on top of command power costs to upgrade generals could be a good idea?
 
I am afraid that during WWII there were only few prototypes. First conflict, where they were really used, was Korean war and at the time only for transport of people and equipment.

It is definitely the case that in WWII they weren't ready for operational service at a level that would make sense in HoI4 (but there were more than prototypes, the YR-4B (27 built) was a production model helicopter that served with both the US and British armed forces). Here's a pic just before the first 'trial convoy-style deployment' in January 1944, during a mid-Atlantic convoy run where the carrying ship was not free to maneuver to ease the helicopter's take-off or landing. The first successful US helicopter prototype (the VS-300) first flew in September 1939.

The results of the trial found that in 1944 that it wasn't ready for operational service (in an ASW role in this case) yet, but the article that this picture is from ('The Helicopter Goes to War', in Warship Vol III) notes that had the submarine offensive not peaked in early 1943, then more funds could have been sent towards the development of the helicopter, and it could have been more useful sooner. In the context of a game that goes until 1948, and not 1945, and includes jet strategic bombers and two tech tiers of jet fighters and bombers (with tech years of 1950), someone asking if there's a role for the helicopter isn't, as best I can tell from what I've read, unreasonable (although it's not something I'd personally prioritise).

YR-4B - the old and the new.jpg
 
It is definitely the case that in WWII they weren't ready for operational service at a level that would make sense in HoI4 (but there were more than prototypes, the YR-4B (27 built) was a production model helicopter that served with both the US and British armed forces). Here's a pic just before the first 'trial convoy-style deployment' in January 1944, during a mid-Atlantic convoy run where the carrying ship was not free to maneuver to ease the helicopter's take-off or landing. The first successful US helicopter prototype (the VS-300) first flew in September 1939.

The results of the trial found that in 1944 that it wasn't ready for operational service (in an ASW role in this case) yet, but the article that this picture is from ('The Helicopter Goes to War', in Warship Vol III) notes that had the submarine offensive not peaked in early 1943, then more funds could have been sent towards the development of the helicopter, and it could have been more useful sooner. In the context of a game that goes until 1948, and not 1945, and includes jet strategic bombers and two tech tiers of jet fighters and bombers (with tech years of 1950), someone asking if there's a role for the helicopter isn't, as best I can tell from what I've read, unreasonable (although it's not something I'd personally prioritise).

Given that gyrocopters were also somewhat proven ASW platforms by that point, too, I'd certainly say it's very much within the realms of possibility that HoI 4 covers. Having them as just a tech with buffs instead of an actual unit or producable equipment piece sounds best to me, though.
 
While I like most of the changes, not the increased research speed; TBH research is already too fast the tech choices are basically meaningless because of it. Would love an option somewhere to control research speed for everybody (including the AI) as would vastly prefer research decisions have meaningful tradeoffs.
 
This DLC still doesn't address the two most glaring issues with this game:

The missing No1 MkIII Rifle and Ju52 2d artwork.

So sad when game dev companies sell out and go mainstream by not including the volley-sight in their artwork for WW1-era rifles... :(
 
I haven't had the time to review all the dev diaries, but of the ones I see, it seems that there is a greater focus on adding features than improving AI. Right now, the game does not have a functioning AI. AI divisions are not designed efficiently, and in waging war it is disproportionately easy for the player to roll through enemy divisions without resistance.

I don't have any DLC, and I'm concerned that by adding new things like amphibious vehicles, it is only worsening the AI's ability to compete. How will they be able to efficiently use the new features if they cannot even use the ones included in the original game? Is this game meant to be played multiplayer? I've been very disappointed compared to how games like EU4 progressed, where AI issues on release were given adequate improvement in a relatively short time frame, before focusing on adding a bunch of new systems or reworking old ones.

As they have said before it's very difficult to do DDs on AI. It basically consists of the phrase "we're working on it".

The AI is constantly improving and will continue to constantly improve but there are rarely any changes that cause such a step change in results that they can write a dev diary about it.
 
I'm hoping they improve the air AI regarding naval bombing and air superiority. It's a bit of a let-down playing the UK or France and seeing the entire Axis airforce is over the English Channel, eastern North Sea and Western Mediterranean, while the land areas are completely empty of planes.
 
I am afraid that during WWII there were only few prototypes. First conflict, where they were really used, was Korean war and at the time only for transport of people and equipment.
I can see an early form of helicopter tech being added in the secret weapons DLC @podcat wants to do. :)

I just hope they're treated as land units/support brigades and not air units! :p
 
I think they said Amphibs are treated as Special forces. This can be split between Amphibs, Marines, Paras or Jaeger as desired.

That's unfortunate.

After extra years of research, after wasting experience on upgrades, after diverting tons of production .... you just hit the cap.

With current marines at least the equipment you produce for them can be used elsewhere once you are capped.
 
That's unfortunate.

After extra years of research, after wasting experience on upgrades, after diverting tons of production .... you just hit the cap.

With current marines at least the equipment you produce for them can be used elsewhere once you are capped.
You can increase your cap via tech, and some countries even get national spirits that increase it further.

It makes sense that amphibious tanks would fall under the cap, and I'm glad they do. They should be important specialist units, not replacements for your standard light tank divisions.
 
You can increase your cap via tech, and some countries even get national spirits that increase it further.

It makes sense that amphibious tanks would fall under the cap, and I'm glad they do. They should be important specialist units, not replacements for your standard light tank divisions.

Still there is a new mechanic being introduced .... equipment you produce may be restricted to be deployed and used because of a cap. This adds extra hassle with management of production.
 
Still there is a new mechanic being introduced .... equipment you produce may be restricted to be deployed and used because of a cap. This adds extra hassle with management of production.

Then, be careful about how much you produce. Fine tuning your production to your overall strategic needs is a skill every player should learn anyway.

However, I do agree that amphib tanks should be able to be converted back to regular light tanks, or at least LSPART/LSPAA/LSPAT

That being said, I can think of lots of opportunities to “spend” my amphib light tank inventory on. Europe has lots of rivers after all.
 
why aren't amphibious tanks just a new kind of variant? Wouldn't that make more sense, knowing how duplex drives were mostly modified Sherman tanks. Making amphibious tanks have they're own branch seems odd to me.

This way would allow AA/TD/SPA variants based on an amphib model