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HOI4 Dev Diary - Mines and Minesweeping

Welcome to another glorious Wednesday! Today we are going to be talking about mines and mine sweeping. Historically hundreds of thousands of mines were laid during WW2 and with Man the Guns you too will be able to do so in Hearts of Iron.

From a gameplay perspective mines do a lot of interesting things. They add more interaction with the naval layer of the game, create a weapon both for smaller naval nations to fight bigger ones, and for big ones to try and limit where the enemy can get to them.

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As you may remember from my presentation at PDXCON, I talked about adding a ship designer to Man the Guns. It is not quite ready to show off, but it’s important to know that sweeping and laying mines are something you will be upgrading or redesigning your ships to be doing. Minelayers and Minesweepers are not actually new ship classes. In my screenies I have destroyers that can both lay and sweep mines for simplicity, but as @Archangel85 pointed out earlier “I am probably going to have a ton of different destroyer designs”... anyways, details on the designer is for a future diary when it is done, but hopefully it helps explain some stuff in the proper context.

Mines are unlocked from techs and require ship designs fitted to deploy them. Destroyers and light cruisers can do this, as well as submarines with the correct tech (excellent if you as Germany want to make things even more dangerous for the British at a lower risk to yourself). Mines can also be dropped from the air with later game techs. Both of these unlock new missions for navies and airwings.
mine_techs.jpg


Mines can be made better and better through research. You start off with Contact Mines to unlock them. Then their destructive power is improved with Magnetic and Acoustic mine techs and finally with Pressure mines. At the bottom (heh) you also see two techs for submarine mine laying. The first is just the basic ability, while the second improves efficiency a lot by allowing mines to be deployed through torpedo tubes, thus no longer requiring you to design specialized minelaying submarines.

To get rid of mines you need minesweeper capable ships. This unlocks the naval mission to sweep mines and will slowly work at clearing areas. Minesweepers are also nice to include in your fleets as they will then be assumed to travel ahead of the fleet and reduce the impact of mines on them. I suspect a good design combo will be anti-air and sweeper on screen ships to be your passive defense when in enemy waters.
mine_report_map.jpg


There is also a passive “degaussing” technology that can be researched after Magnetic Mines. This was employed during WW2 to reduce the magnetic signature of ships and thus make them less likely to set off mines.

It is also possible to sweep mines from the air, but this is a late game, expensive technology and unlocks a new air mission for bombers. This was something that was done sparingly and in shallow waters, but for example was successfully done to evacuate the Dutch royal family to Britain.

What do mines exactly do then? Well they blow stuff up! Their explosive results are shown on map as accident reports, and there is a new tab too under the Naval Losses statistics interface if you want to dig into details. As ships operate or move through a zone they will risk running into mines. This can lead both to minor damage as well as outright sinkings. The best ways to avoid this is to make sure the area is swept free of mines, but as mentioned above, having your ships travel with sweeping capable ships makes it safer for all.

mines report.jpg

This is not all through, mines have several passive effects.

Naval superiority - Having mines in an area helps amplify the effects of your navy (after all they can concentrate more effectively knowing where the mine fields are). This can be seen in our new naval area screen, which is the naval equivalent of the state view:
travel.jpg


Other than that and blowing ships up mines will slow down enemy ships (since they need to be more careful) and increases the invasion penalty to coastal area. So mines are both good offensively and defensively.

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Mines can only be laid while at war and will start to disappear over time once a nation is completely at peace. You always know how much mines there are in an area, so you know how to deal with them and take them into account. That means that with the new naval access controls you can tell your ships and convoys to avoid heavily mined areas, but of course this may make it a lot more predictable for your enemies where to hunt. Having an advantage in the encryption-decryption war will also add a certain amount of passive defense against mine effects as you may have some information about their positioning.

See you all next week for more Man the Guns info!

Rejected Titles (for extra good reason this time...):
- This War of Mine
- Vengeance is Mine sayeth the Lord Admiral
- Do you mine’d
- This feature was made in cooperation with the seagulls from Finding Nemo
- Mine = blown
- The Ship Designer isn’t unfinished, it’s just a bit shy
- Minesweeper 2000 Online HD Edition
- Mine over Matter
- Mine the guns
 
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I think you should be able to clear mines in a seazone by voluntarily playing (and winning) a game of minesweeper. It would really add to the immersion.

I wish Paradox would take some inspiration from the game Svea-Rike. For those who don't know, it was a grand-strategy game about Sweden which amongst other things featured a space invaders clone were you shot a cannon at cossack-dancing russian invaders.

In all seriousness though, I would enjoy seeing more minigames in strategy games. Perhaps not minesweeper in HoI4 or Cossack invaders in EU4, but gambling with other characters in CK2 perhaps?
 
Will naval mines be free or come with MTG?
The mines themselves are a separate microtransaction - $2 per mine field laid.
 
The mines themselves are a separate microtransaction - $2 per mine field laid.

Or free if you can clear a large minesweeper map in less than 60s.
 
Thankyou for this Dev diary can't wait for the next one which can explain more about naval terrain.
actually the next one isnt about terrain, but its coming. its kinda tied in with combat so while we got it rolling I cant show it properly without all the other stuff ;P
 
btw. seems @TomaszKowalczyk actually added mine decay in peace time :D he had forgotten to tell me. So mines do not actually instantly dissapear, there is some time between if another war kicks off. I'll update the diary itself
 
@podcat

Do you prefer the Hood or the Nelson as your starting flagship?



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btw. seems @TomaszKowalczyk actually added mine decay in peace time :D he had forgotten to tell me. So mines do not actually instantly dissapear, there is some time between if another war kicks off. I'll update the diary itself
That's good. E.g. Finland was still clearing mines into the 1950s, a dangerous task in which many people died. Actually some mines have still been found in archipelagos during the 2000s.
 
Are we going to see new naval units in the new dlc? I'd like to see Light Carriers being utilised by minor-semi major nations as a cheaper alternative to aircraft carriers as well as give other nations the chance to research naval units which were used by specific nations
 
@podcat

Do you prefer the Hood or the Nelson as your starting flagship?



,,,,,,,,,,,,,,,,,,,,,, :oops:
Personally? Nelson obviously. Big guns are all that counts in my book
 
Will there be a balance to where these mines can be dropped? I.e british+allies could mine the entire mediterranean sea before italy joins the war. And allies could also mine the whole pacific and give japan a churchills dardanelles campaign scenario when leaving his ports on his late war entrance
 
This land of mine is a great film for anyone that has not seen it. About the Dutch/allied armies using German boys whom were conscripted in the final days of the war to de-mine the Dutch coast.

Great DD and mechanic. Hoi 4 team is #1
 
Check out :
Laws of War :
Laying of Automatic Submarine Contact Mines (Hague VIII); October 18, 1907 http://avalon.law.yale.edu/20th_century/hague08.asp


Will HOI4 MTG follow the Hague Conventions of 1899 and 1907 ? Will there be any penalties if a nation break those (of course nearly all nationss signed it and iam sure lot of democratic countries may become angry if one break Hague Convention isnt it?)

Please share your thoughts?