Hearts of Iron IV - 48th Development Diary - 11th of March 2016

[podcat]

Hi everybody, the topic for today is Naval Invasions.

The main design goal for naval invasions has been to make invasions something that requires a lot of preparation to make it possible to pull off, combat "gamey" tactics of sneaking troops in when others are not looking and make it clear how you go about defending yourself, something that requires both navy, air and land.

Let's start with what is required to do a naval invasion:

• You need to position troops at a starting naval base and draw up an invasion plan for where you want them to go.
• Before the invasion can be launched you need to prepare the invasion. This is first a matter of needing a certain amount of convoys available (which the invasion plan will grab) and a time. Both these depends on just how big this invasion is. Small invasions can be planned and executed quickly but large amount of divisions will require plenty of preparation time.
• For each strategic area you pass through with the invasion plan you must have sufficient Naval Supremacy. You get that by having sufficient amount of ships on patrol and by controlling the skies (air superiority). If you do not control these things you won't be able to invade (no sending your whole army to suicide). This makes it pretty clear now to defend as well. For example as UK - as long as your fleet is strong and stationed around the island and your air force is up and about you can feel safe from naval invasions.

There are also things you can do to improve your chances of successful invasions:

• Use special troops - Marines are much better than other troops for securing the beach.
• Make sure to always have ships set up as escorts. Even if you have sufficient naval supremacy to launch the invasion - if the enemy rallies their whole fleet after the invasion is already under way there is still a chance some of the convoys could get intercepted.
• Station battleships in the destination coastline. They will support the invasion with naval bombardment which will help your guys get the edge when fighting on the beaches.
• Use a commander with the Invader trait, he will help speed up the preparation as well as speed up to time it takes to get invading troops ready for fighting.
• And finally: make sure to research transportation technologies. The really useful ones are only available from 1940 (unless you research ahead with the penalties for that), but you can improve things like: Needing less transports to carry out invasions, halving the preparation time required, get extra defense from damage taken during invasion and speed up the time it takes for your troops to get out of the ships and on to the beach where they can fight.

The actual invasion combat has some special rules. Once troops land they first need to unload from ships and during this time they are unable to fire back effectively. If you have the right technologies researched troops will actually get some extra protection during this time, but still it's something you want to do as quickly as you can. Once on the beach they can fire back, but will still be suffering from naval invasion penalties.

Next week we'll talk about nukes!

 

[podcat]

I'm actually very interested in how much supply is secured when landing on a beach/harbor. A rough guide would be nice since a lot of forces were lost in WWW to supply issues after landing!

Basically, you need to secure a naval base. Depending on the base level you can move in a certain amount of supply. Any local supply you need to link up with (take over area/VPs)

Will convoys be locked for invasion plans or can you just not execute the order if you're lacking convoys?

convoys get reserved by the invasion order when created and you can launch it until it has enough.

Sounds more structured than in previous games, and that's nice.

How does one integrate airborne troops into the whole thing?

well its a while different things. Paras we might talk about in a future diary separately. Basically its like naval invasions but not with a long planning phase. You need to deploy transport planes from their air bases to move the paras and drop them and any area they pass though requires fairly high air superiority. Paras also get shot at by AA (or enemy planes) so are likely to be damaged on landing.

As well as marines can we land amphibious tanks and the like? Or only infantry?

you could mod some in. We dont have special tanks for this. You can try to land tanks but they are aweful at it.

Can naval invasions be part of a multi stage plan - i.e. land here then advance to this battle line?

Yeah you can multistage:

Can only battleships be used to support naval invasions?

no, any capital ship (well not carriers directly at least) can.

Also, how are sealifts between friendly territories handled?

I'm worried that someone could plan a lightning 1 division invasion with minimal prep and then land 10 divisions behind. Not unlike the old hoi2 exploit of taking plymohth with paras and then having transports preloaded with the entire 6th army sneak in.

as someone already said, then its not a large invasion and if enemy leaves a gap open its their fault. Its generally not a problem because swatting down single guys isnt so hard.

Thank you for the DD. Nice to read one that wasn't covered, in detail, during the WWWs.
I'm assuming that the nation being invaded can improve their defense defenses against invasions, as well? Would this be done through research, too? How?

well, you defend using air/navy so its part of the standard stuff. you can build naval forts as well.

Is the invader trait assigned to Naval commanders or Army commanders or is it a combination of both?

army commander.

I am curious how multi-nation naval invasion is handled like the June 6th day landings? Would they be several separate invasions or is it possible for multiple nations to be used as one force?

separate invasions, but you can see when ai plans to launch. you can also give over expeditionary forces

 

[podcat]

So you can't create a template using Marines with a little bit of tanks battalion ?

you can, but the penalties of tanks are so bad that it wont be a good idea. but sure they are better than just tanks at invading

 

[podcat]

Can we please get notification about landed invasion? I can live without knowing my country is going to be invaded if i have not enough intel, but not being notified that I'm attacked when I'm focusing on the front on another continent, can be troublesome.

you get told:
1. when the invasion is spotted. If you have radar and ecryption/decryption thats early. or if you have ship patrols around and they spot it
2. if all else fails the second the transports enter the province next to your shore you get told

 

[podcat]

What support brigades would fit well with marines during an invasion?

engineers

 

[podcat]

Can I get around the long prep time required by a large invasion by splitting it into several simultaneous small invasions?

if you have enough available ports to run them from yes. Generally this means you need to manage more naval supremacy

 

[podcat]

If we keep following this path, we will start seeing random DD's about country X. Which for the most part people would care less.

We've already made a whole bunch of those. They seem well received (but we already covered all the majors now I think)

Wait, so are there different kinds of landing craft, or are we just using generic convoys and our tech determines how "protected" our troops are when landing on beach?

Also, is naval supremacy a binary function, or is it more complicated?

For example: Germany and the UK are at war with each others alliances. The English Channel is a sea zone. What are the options for Naval supremacy? The UK only? Germany only? Or is it possible for neither side to have naval supremacy? Can Italy gain naval supremacy to let Germany run an invasion (faction wide supremacy)?

you share supremacy with allies. Its binary, so it doesnt matter how much you have as long as you have enough to do invasions. Of course the things adding up to the supremacy value are all things you want lots of and that will help (like more fleet and air force)

there are no special landing craft, you use convoys and research techs to improve things.