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HOI4 Dev Diary - New Naval Combat

Hi everyone! Since forums were all down yesterday the diary is coming today instead :) Today we are going to look at core changes to naval combat coming in 1.6 Ironclad. We have already discussed how missions are changed as well as basics of the new spotting system in a previous diary and a future one will be fully dedicated to submarines so I will only cover them a little for how the interact with regular fleet battles today. So lets charge in!

Its best to start by looking at problems in the old system so you can see how we have tried to solve them and iterate. We identified the following:
  • Battles are extremely decisive so tiny mistakes have bad consequences
  • Combats tend to snowballs as everyone and their mother’s fleet pile in
  • A big fleet was always better, together with the above point promoting doomstacking
  • The interface gets very confusing as ships close with each other. Distance overall is very hard to show and balance.
  • It is easy to miss a combat happening while busy elsewhere.
  • Its “simulation nature” made balancing an incredibly hard problem. Resulting in things like the all-battleship fleets performing well.
“Battle-lines”
battle.jpg


To deal with distance and screening issues we have split up the battle in 4 areas per side to represent position and distances.

Screens - Your screen ships go here. Screens are the closest to the enemy and protect the ships behind them (details below).
Battle line - This is where your big guns sit. Heavy cruisers, Battleships etc. Anything with heavy long range guns. These guys also help to protect carriers and convoys behind them.
Carriers - Furthest back are carriers protected by the other two lines. This is also where convoys will be if part of the combat (say during invasion or a convoy raid battle).
Submarines - Under the sea. This area is actually two as we separate located submarines (which can be engaged with depth charges) from unlocated submarines.

By splitting things up in discrete distances unlike the old system we can more easily capture the impact of distance and positioning, and keep it easier to see what is going on at a glance.

The area they are assigned to depends on the weapons they have, which makes things tie in neatly with the ship designer. Rules for combat are now largely depend on how different weapons interact with the areas, so it is important to go over them before we continue. We also show these summarized at the top of the combat screen for quick information and to help you evaluate the combat situation:
stats.jpg

Light Guns - These are smaller caliber guns. The armament on destroyers/light cruisers and secondary armament on heavier ships. Their job is to hit and kill smaller fast moving ships. They generally do not have the armor piercing to lay down serious hurt on capital ships. Light guns attack ships one line over. So screen ships can shoot other screen ships, and when there are no more shoot the enemies capital ships. Capital ships with secondaries can fire from behind the safety of the screens at the enemy screen.

Heavy Guns - These are hard hitting armor piercing guns designed to take out big ships. They have trouble hitting small fast ships, but when they do it is for significant damage. Heavy guns have the range to fire over one of the enemy lines. So they will be hitting the enemy battle line even if it is screened.

Torpedoes - These are the big capital killers. They ignore armor, and have big damage but are terrible at hitting fast/small ships. Torpedoes can hit any line as long as it is not screened properly. So if your screening is down to 50% then half of the enemy torpedoes can be fired at your battle line, and if the battle line is also weak some torpedoes can slip through and hit carriers or convoys.

Anti-air - AA works a bit different. When firing back at enemy planes a ship will also get a part of the fleet’s AA armament to help it, so it’s quite nice to make sure your support ships (or battleships if you focus on carriers) are stacked with as much AA as possible.

Depth Charges - This is the only weapon that can hurt subs, and it only works versus revealed subs.
Carrier Planes - Carriers can carry different kind of planes. Naval and dive bombers help attack other ships and fighters help protect yourself. The whole air model in naval combats is now more in line with the rest of the game and takes place in the airzone as you would expect. So can now be disrupted etc. This fixed a bunch of issues we had with the interaction between land based air and carriers.

sub.jpg


Next to the weapon summaries we also display the side’s positioning value. This is a value simulating how well positioned your task forces are. A low positioning could for example mean that all your screens are scattered in a storm and your capital ships are wide open to attack. Positioning affects screening directly and a low value will directly hurt the fighting abilities of the ships as they wont be in optimal range, have another ship fouling the range etc. A big effect on positioning is the relative sizes of the fleets. So the bigger fleet will have an inherent penalty to its positioning versus a smaller, more easily controlled force. An admiral’s maneuver skill helps with this though. There are also traits like Lone Wolf and the Capital Ship Raiders tech from the Trade Interdiction doctrines that help increase this penalty for the enemy. The idea is to make smaller capital raiding forces more competitive if you tech right and have a trained Admiral in charge.

screening.jpg


Tooltips for ships now give great breakdown on where the damage is coming from so you can see how well (or not) a particular weapon type is doing, there are also totals summarized in the top of the interface.
dmg.jpg



Entering and exiting combat
After the initial battle starts, further task forces can join. When they do they get put in the “Incoming” box, much like before. The time spent there depends on their org levels. The lower the longer they have to wait to join. Org is affected by moving, but also by giving manual orders to fleets (we want you to plan ahead, not react for max efficiency). Whenever ships are called to a combat, they will take an organization hit, which slows down their joining. Similar delays also apply for missions like convoy raiding or escort at suboptimal efficiency so it’s harder to bring all your power to bear at the same time.

On the flip side, if you take out the enemy side before the incoming ships arrive, the battle ends and you can run away (or the sides have to re-spot each other if they still want to fight), the idea is to help subs and other raiders out by allowing fast hit-and-run battles.

run.jpg


As for exiting combat that is both something you can order directly and something that happens when ships take enough damage (remember, you set up aggression levels to control how risky you want your task forces to be). Retreating is a process that takes some time. It is affected by doctrines, traits, weather, terrain, and the speed of the ship. We show it as a progress bar so you can bite your nails as the enemy pride of the fleet slowly gets away. Note that we also now have critical hits which will slow down ships and making it harder to run - a ship with a jammed rudder has a wooping 90% penalty to escaping. Escaping is an important part in keeping battles from being too decisive.

This is also where submarines come in. They follow normal torpedo rules, but also free to circumvent them when it comes to escaping ships. So if you have subs hiding in your battle they can engage the enemy capitals as they start to run (of course this reveals them, depending on doctrine levels, leaving them open to return fire from anti-sub vessels).

See you next week for a look at submarines :)

image.png


Rejected Titles:
- Sinking inside the box for a change
- Bravely retreating in the face of underwhelming odds
- Man, those guns!
- "Stop writing dumb titles and post already podcat!"
 
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Okay. I've been fine the past few months, but now this is killing me. I figuratively can't wait for this anymore. I'm sooooooooo excited for this. This sounds amazing.
 
I guess that depends on your definition of 'fleet carrier'. HMS Glorious, albeit being a converted battlecruiser, could house 48 aircraft, so was of a reasonable size. Escorted by just two destroyers she was sunk by the Scharnhorst and the Gneisenau, before getting any aircraft airborne.

That was due to gross negligence on the captain of that CV. No alert aircraft, smoke spotted but nothing done, Ignored warnings, Plus a few more errors. So yes if they add gross stupidity to the leaders then it can happen.

The reason I say it never happened and would never happen is because orders given to the CV fleets (except for CVE Taffy task force) was ALWAYS to stay out of gunnery range. And I can't find a single instance where in a CV vs. CV fight the admiral ordered the surface portion to engage the enemy CV's at gun range. It just never happened. And one MAJOR reason why is finding out where the hell those CV's are at. Without aircraft to spot and locate them how the hell would the surface component know where to go?
 
What if I have more than one task forces engaging in battle in a sea region?

For example, TF1 for air strike,
  • 2 Shokaku + 8 Akizuki
TF2 for surface engagement,
  • 2 Kongo + 4 Takao + 2 Agano + 8 Shimakaze
And TF3 for sub hunting,
  • 1 Nagara + 8 Matsu
So I would expect the AA-specialized Akizukis in TF1 to stay back around the carriers and focus on escort role, and let the torpedo-specialized Shimakazes in TF2 to be at frontline and fire torpedoes at enemy ships, and the ASW-specialized Matsus in TF3 to evade any superior enemy fleets.

Is this possile in the new combat system, either automatically managed by ai, or by player manually assign different roles to the three task forces?
 
What if I have more than one task forces engaging in battle in a sea region?

For example, TF1 for air strike,
  • 2 Shokaku + 8 Akizuki
TF2 for surface engagement,
  • 2 Kongo + 4 Takao + 2 Agano + 8 Shimakaze
And TF3 for sub hunting,
  • 1 Nagara + 8 Matsu
So I would expect the AA-specialized Akizukis in TF1 to stay back around the carriers and focus on escort role, and let the torpedo-specialized Shimakazes in TF2 to be at frontline and fire torpedoes at enemy ships, and the ASW-specialized Matsus in TF3 to evade any superior enemy fleets.

Is this possile in the new combat system, either automatically managed by ai, or by player manually assign different roles to the three task forces?
Good question, going a battle stack or get sucesives engages by task forces...
 
Wait.... so.... naval combat is going to be the best part of the game instead of the worst? I know that was the intention of the dlc, but I am surprised that it actually sounds like they are pulling it off. No offence to the devs of course! :D New naval combat system looks so solid!
 
@podcat
thinking about what you showed in the DD concerning Midway. I could really tear it apart from a historical perspective but on the positive side, if you were attempting to simulate the search and destroy Bismarck mission, then this is pretty close and given the past naval warfare performance of HOI IV, this is a huge improvement.

Lets move to the Pacific side for a moment and understand that even old surface fleet Admirals like Spurance got the new Carrier tactic. He strategically placed his two carriers in a position where a surface battleship could not engage them. He sent his aircraft to go find and fix the enemy. He was looking for carriers not battleships. The other thing to keep in mind about Spurance was that he was not the TF's usual commander. Halsey was out sick. Yet Spurance performed just fine and did not make surface commander mistakes, he understood the new carrier tactics. HOI IV should simulate this carrier to carrier battle, Midway, as well as the hunt for the Bismarck. I think its possible with the new combat structure, but I am not sure. Can HOI IV demonstrate lessons learned and perform as well as Spurance?

Can a carrier task force set itself back within its aircraft range?
Can a carrier task force's screen stay within sight of its carriers, providing AA and ASW for the carriers?
Can a carrier's air wings be given missions that correspond to the plane type? For example, Fighters usually get either CAP or escort missions. Fighters could search but it is the rarest of its three missions. Dive bombers and Torpedo bombers were usually assigned Search and Destroy or sent to the most likely location to destroy carriers.

In addition to the above questions could you also answer these from @xustc:
What if I have more than one task forces engaging in battle in a sea region?

For example, TF1 for air strike,
  • 2 Shokaku + 8 Akizuki
TF2 for surface engagement,
  • 2 Kongo + 4 Takao + 2 Agano + 8 Shimakaze
And TF3 for sub hunting,
  • 1 Nagara + 8 Matsu
So I would expect the AA-specialized Akizukis in TF1 to stay back around the carriers and focus on escort role, and let the torpedo-specialized Shimakazes in TF2 to be at frontline and fire torpedoes at enemy ships, and the ASW-specialized Matsus in TF3 to evade any superior enemy fleets.

Is this possile in the new combat system, either automatically managed by ai, or by player manually assign different roles to the three task forces?

Please @jju_57 allow @podcat to answer even if it is a new thought for him and may have to be postponed until the next DLC but imho this is the perfect place to get carrier battles really into HOI IV and demonstrate why battleships became obsolete after WWII before missiles became the weapon of choice for surface combat.
 
@jju_57 allow @podcat to answer even if it is a new thought for him and may have to be postponed until the next DLC but imho this is the perfect place to get carrier battles really into HOI IV and demonstrate why battleships became obsolete after WWII before missiles became the weapon of choice for surface combat.

Sure he can answer... again. But he already has answered your questions so I doubt you'll see another post here. In this and the other DD's all of your questions have been covered.

Funny that shomehow you think I have the power to prevent him from saying anything here and that I have to "allow" it else he won't respond.
 
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Great work.
We hope we don't see again situations like Italian AI sends on day 1 his entire fleet against english one, or even italian AI sends troops for a walk around the Mediterranean while enemies had naval superiority.

Hope also that this silly HOI AI can manage all your beautiful work.
 
@podcat

Have you considered a new achievement called There's No Business Like Shōwa Business ?
 
For historical accuracy, you could make Britain automatically win all Naval-related things! RULE BRITANNIA, BRITANNIA RULES THE WAVES!

But of course, nothing better than seeing the glorious achievements of vessels such as the HMS Hood or HMS Prince of Wales during the war while drinking a cup of Earl Grey Tea.
 
Once again, great changes!
 
Sure he can answer... again. But he already has answered your questions so I doubt you'll see another post here. In this and the other DD's all of your questions have been covered.

Funny that shomehow you think I have the power to prevent him from saying anything here and that I have to "allow" it else he won't respond.
Thank you for taking the time to properly read the dev posts and then help the people who missed the information. Also, please reinstate Podcats posting rights.
 
I'm really hoping there's much more to this, because it doesn't seem remotely capable of modeling carrier battles as it's shown now. And since it now appears that the aerial mechanics are going to undergo minor tweaks at best, naval striking in a seazone is not an acceptable replacement. (Nothing nonsensical about having those 2,000 land-based fighters living off of "local supply" fly LRCAP over your fleet at all times, right?)
 
Im starting to think the victoria 3 team is developing Man the Guns.

Also are you guys gonna add more formable nations with this new dlc? Like (Hopefully) Babylon, and maybe even an Iberian Ferderation or a Spanish Monarchial thing like how Denmark, Sweden, and Norway can form (the one w/o Finland) where it has Spain, Portugal, and Naples. or maybe even a Chinese empire, or the Sultanate of Rum, oh and most important the Mongol Empire, this could also double as a hard achievements speaking of which why isn't there an achievement for forming Rome?

also could you maybe add the following releasable nations, thier reasons are stated w/ them...

North Korea, possibly as an event like the East and West Germany event, cuz North and South Korea are a important historical outcome of the 2nd World War on the Pacific Theater
Texas, cause i'm Texan, and we're are being illegally occupied by the Americans
Catalonia as a releaseable nation as easter/reference to the upcoming EU4 DLC, Golden Century. (Maybe even Navarre or Glacia if your feeling spicy)
Venice, Venice.
Bavaria, cause of the 1919 Socialist Bavarian war for independence, which failed but still
Somaliland, I think you added this in this dev diary but I could be wrong but still its kinda an important thing in East africa
Katanga, cause of the War for Katangan independence from the DRC, it may have been in the sixties but hey, Katanga, roll off the tongue so why not
Kurdistan, cause well kurdistan (I can understand if not included cause of... well... politics... yeah...)

Thank you, and have a nice day!
 
From a GUI standpoint, wouldn't it make sense to put some "perspective" into the battle-lines? The 2D nature of strait lines combined with the sub-surface area for subs and aircraft isn't immediately intuitive (it looks like the ships are flying, at the same height as planes). Minor thing but it took half a second to force my brain to disregard the notion (which is a bad thing in GUI design).
Just tilting the lines slightly inward towards a "horizon" would make a lot more sense IMO.

2reqeyd.jpg

Simple intelligent solution. I really think Paradox needs to use the community for things like this. Maps, Portraits, and units also.