I created a lot of submarines as Germany to try to bring british industry to a halt by cutting off the supply. How to organize submarine fleets for best interception percentage? What are the tradeoffs?

1. Hoi4 Doctrine Comparison

Group size?For subby hit-and-run smaller fleets (1-3) sounds better but one can hardly afford a leader to all of them, let alone one with a spotter or sub-master skill. Also, I imagine too large a fleet would not be optimal either.

Distribution?When to use any such 'properly sized' fleets in 1 specific region vs have larger overlapping areas for each sub fleet?

Unfortunately the game seems to lack any strategic 'spreadsheet' or diagrams to measure trade interdiction progress.

1 Answer

'Broscience' says the groups of 7-9 subs are most optimal for Germany - good punch and still good stealth.

Hoi4 Doctrine Comparison

I completely agree with you! I somewhat dislike the lack of distinct malus for the combination of non-fitting doctrines. In my current game as Germany I have a combination of Armored Spearhead/Blitzkrieg-Doctrines and do also use American Superior Firepower-Doctrine to give me +1 Brigade-slot per Division and British +5% reinforcement chance tech, simply because it gives me a bonus. Mobile warfare. The main goal of this doctrine is to wage war basing on vehicles. Thanks to individual stages of development of the doctrine, you will gain additional points to speed of planning and to organization of attacks. It is useful both in the case of invasion and defensive war. Thanks to the versatility, it harmonizes with mobile warfare and mass attack doctrines. This doctrine will be interesting to all of the players who rely on their aviation for the strength of their army.

I am not aware of the possibility to change a supply root tranjectory so it only make sense to set the sub at the busiest regions. If you can handle it one sub group only one region.

Recommended regions: Coast of Africa and mid Atlantic - less British fleet and a lot of traffic, avoid English channel, as too heavily guarded.

General sub tips so far:- I call sub fleets 'sub 1', 'sub 2', etc- Create a many production queues as i have sub fleets and direct the newly produced subs to the fleet directly- Set engagement level to 'not engage' and repair priority to yellow- Avoid placing subs to the ports easily accessible by enemy bombers (unless you have air superiority) - so basically avoid English channel coast line- Place a good commander- Combine subs with nav bombers

Yes, the ledgers are gone, they might be back though. If you keep sub notifications for a month you can see on the map which regions are the most successful and therefore find a good engagement region.

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I compiled a little guide on how the different land doctrines operates. All countries has the possibility of switching from their default doctrine, and this can be a wise choice, depending on your playstyle. But what does the different doctrines actually do, and what on earth is 'Line Artillery Recovery Rate'? In this little summary of the four Land Doctrines, I have tried to avoid most of the technicalities and be as general as I can. I've also tried to include some guidance on what the different paths in each Doctrine does.

Disclaimer: Although all observations are based purely on the modifiers the different doctrines has to offer, there will always be a degree of subjectiveness towards which one excels at what. I've tried to be as impartial as possible, but I would love your input.

• Extremely powerful combat bonuses

• Focuses on mobile divisions, especially tanks

• Great on the offensive, the worst doctrine when losing

• Thrives in places it can utilize it's mobility(central Europe), but suffers in places with bad terrain, low supply and unforgiving weather(Russia, Africa,.).

• Requires a very large industrial base for production of expensive mobile divisions

Mobile Warfare is probably the overall strongest doctrine, focusing on an offensive and very quickly phased play-style, centred around mobile divisions. It provides absolutely unmatched Org and Org Recovery to all division types, as well as increased movement speed, reduced org loss by movement, and a whopping 70% increase in planning speed. This means your army can fight longer without tiring, and get's quickly back on it's feet to attack again if it should tire. Using this for it's maximum impact often requires some micromanagement from the player, and preferably a country with a larger industrial base. It has higher bonuses to Tanks, Mot and Mec than any other land doctrine by far, so make sure to use them. Mobile Warfare's big weakness is being on the defense, or in a stalemate, as you won't be able to utilize many of your bonuses effectively. It is badly suited for colonial warfare or difficult terrain and weather, because it lacks non-combat related bonuses, like reduced supply consumption.

Mobile Infantry or Blitzkrieg?
This is an easy one. Sorry, Blitzkrieg, but Mobile Infantry is just overall better. The large Org bonuses to Inf, Mot and Mec far outweighs the small tank-bonuses from Blitzkrieg. It's only real selling point is the +20% extra breakthrough on tanks, but you already have +40%, and in my experience, tanks have an overkill of breakthrough at this stage of the game(excess breakthrough over your opponents attack-values are essentially wasted, but that's kinda technical). Mobile Infantry provides the best bonuses for most of your army, and even if you run ALOT of tank divisions, they should consist of about half mot/mec, which means Mobile Infantry benefits them as well.

Desperate Defense or Modern Blitzkrieg?
Modern Blitzkrieg is the obvious first choice. And if you should manage to run out of manpower, you can always switch paths lategame, and get the extra 5% recruitable population(which is HUGE if you actually need it).

• Jack of all trades, master of none

• Great at stale fronts, utilizing it's high entrenchment and planning bonuses Viruses for android are they exist in america.

• Balanced between offensive and defensive abilities

• Emphasis on Inf, Mot and Mec - provides the most powerful offensive Infantry bonuses

• Requires no special industrial base.

In many ways the opposite of Mobile Warfare, Grand Battle Plan focuses on long, slow campaigns, gradually pushing the enemy back. Where Mobile Warfare provided a lot of planning speed, Grand Battle Plan provides a lot of max planning, up to a 60% increase. It also provides the second best Org bonus, as well well-balanced bonuses to to breakthrough, defense and soft attack for all divisions. It does fine in both offense and defense, but excels in neither. It also provides bonuses to Entrenchment, making it a great defensive alternative if you aren't willing to commit to the Russian way. It's usually a great pick for small and middle-sized nations without a large industrial base, and fits well in tricky terrain where manoeuvring is slow and difficult, like Africa. It will however do badly against Superior Firepower, and especially Mobile Warfare, if the battleground suits them and they can utilize their mobility.

Assault or Infiltration?
There's not really a wrong choice here. Assault offers some small extra bonuses to armed and mot/mec, and doubles the max planning bonus from 30% to 60%, while Infiltration mainly gives -10% supply consumption and +25% night attack. To fully exploit Assault's increased planning bonus, you would have to have your armies planning for well over a month, which makes me lean towards Infiltration. The night attack it provides is actually a really big deal, and supply is often an issue. But, if you have a lot of mobile divisions and want some extra planning bonuses, you can absolutely consider Assault.

• Good general combat bonuses

• Great at preserving manpower

• Focuses on an Infantry/Artillery heavy unit composition

• Balanced between offense and defense, with a slight preference for defense

• Requires a large industrial base for production of costly infantry divisions

Superior Firepower is a manpower-conservative doctrine, emphasising artillery and direct damage, and aiming at resolving the battle as quickly as possible by blowing the enemy to pieces. It provides absolutely unmatched bonuses to Soft and Hard Attack(a bonus almost completely lacking in all other doctrines). Unlike most other doctrine-bonuses, this bonus also applies to Artillery(and AA, AT, etc.), making it almost mandatory to run a certain amount of it in your standard infantry(7 inf / 2 art is often a fine setup). Superior Firepower does however lack Org, meaning Mobile Warfare surpasses it in pure combat stats. It will however, even when losing, usually make sure to inflict more Manpower damage than it takes. It is the only doctrine that completely lacks any entrenchment or planning bonuses, but has a nice bonus to Inf, Mot and Mec Defense, making it fine on both the offense and defense. Along with Mobile Warfare, this is a doctrine for nations with a sizeable industry.

Dispersed Support or Integrated Support?
This pretty much adds up either way. Playing as a nation that picks up Supererior Firepower, you will be running both full support battalions, and a decent amount of artillery in all infantry divisions. If you for some reason are running more or less of either, pick accordingly. There is also an argument to be made for Integrated Support if you are running lots of mobile divisions, as they will have no line artillery. Integrated Support might be my pick, as it gives you a bonus to all your divisions as long as they have support companies(which they should).

Airland Battle or Shock & Awe?
Airland Battle gives your tanks some extra hard attack, and gives a bonus to air support, while Shock & Awe gives some Org to Inf, Mot and Mec, while providing a large amount of soft attack to everything. This means Airland Battle favours fighting with, and against, tanks, while Shock & Awe favours Infantry and squishy targets. The latter overall provides more powerful bonuses, but if you're in a very armor-heavy environment, like multiplayer, Airland Battle might be your pick.

• Poor general combat bonuses

• Very powerful other defensive bonuses, to supplies, manpower, partisan effects on enemy etc.

• Heavily focused on cheap Infantry

• Very defensive

• Great in difficult terrain, weather, and low supply areas

Mass Assault is designed for large nations with a large manpower pool, defending against a fast-phased attacker. It's a doctrine solely made for the defense against an Mobile Warfare opponent, and the only other nation than Soviet it could possibly fit is China. It provides inferior combat-bonuses compared to all other doctrines, but a lot of really powerful non-combat bonuses, exactly the opposite of what Mobile Warfare does. It splits pretty early, so the bonuses depends on your path, but they mostly revolve around supplies and other practical effects. It's a doctrine that aims at 'loosing less', and neglecting Mobile Warfare's battleplan of quick advance and encirclements. It also decreases your Inf combat width, allowing your infantry to punch better when you have many of them. It is generally an Infantry and Manpower focused Doctrine. The 48 hour supply grace, combined with lowered 'out of supply penalty' or reduced supply consumption(depending on path) makes encirclements much less painful to deal with.

Deep Battle or Mass Mobilization?
This is solely a question of 'how much are you losing?' Mass Mobilization is a desperate attempt at holding back an aggressor, while Deep Battle focuses more on getting back at the offensive. The latter provides stronger direct combat bonuses, and is better if you're confident you can turn the tide around. It has a sweet -25% Org loss when moving, and -20% supply consumption, making advancing into low-supply areas much more comfortable. Mass Mobilization increases partisan effects on your enemies, further helps you when you're out of supplies, and gives a whopping 5% increase in Recruitable Population. Are you planning on getting on the offensive? Pick Deep Battle. In multiplayer against a Paradox Developer on Germany? Pick Mass Mobilization.

Keeping your default doctrine can be a part of getting the historic feeling of the country you are playing, but if you should wish to switch to a better doctrine, here are some options for a couple of countries:

Germany - ..lol. Mass Assault? I'm kidding. Please don't play Germany with Mass Assault. Mobile Warfare is made for Germany, keep it.

Soviet - Soviet should usually switch doctrines, as Mass Assault's main purpose is defending against Germany. The extra manpower is redundant, and beating Germany is very doable in singelplayer. If you are in multiplayer, you might consider keeping it, especially if you expect to be overrun. Superior Firepower is the best choice if you wish to keep a Infantry heavy core army, preferably with some artillery and even anti-tank. If you like tanks and mot/mec, Mobile warfare is a good choice.

United States - Superior Firepower fits their playstyle pretty great. Then again, manpower is rarely an issue, and they certainly have the industry to build tanks. Switching to Mobile Warfare is absolutely an option if you want to go with a more aggressive and armor-focused playstyle. Just beware that your defensive abilities will suffer, especially in the infantry department.

Japan, Italy, UK - These are all kinda in the same boat. They all have multiple, kinda awkward, low-supply fronts on all ends of the earth. Africa, India, China, and all kinds of Islands. Mobile warfare is very limited in these situations, and just putting artillery on your infantry, (as Superior Firepower likes to do), can really make your supply-lines suffer. Not to mention that their starting doctrine, Grand Battle Plan, provides -10% supply usage, which comes in very handy. Honestly, sticking with Grand Battle Plan is the safe choice. But if you want to invade the United States, roll over Europa, or have some other crazy ideas, while also being confident that you can handle Africa, China or whatever, go ahead and switch to something you are more comfortable with. Grand Battle Plan is not exactly ideal when going head to head with i.e. Germany.

Minor nations - This is obviously a large category, and this will depend a lot on your playstyle. Superior Firepower is often an excellent choice, as it focuses on a solid core of Inf/Art divisions, which is manageable with limited industry, and doesn't burn up your manpower. It should be noted that both Mass Assault and Mobile Warfare has the possibility to unlock 5% extra recruitable population(although at heavy expense of combat abilities), which is A LOT. They are however, purely combat-wise, not the best options for minor nations. Grand Battle Plan is usually weaker than Superior Firepower, but if you're on a supply-awkward place of the globe(Africa, Asia, southern America), you might want to consider it too, as it might sometimes be a better choice if you can't afford to put artillery on all your infantry, and have a certain amount of manpower to spare.

In the end it's a question of taste and playstyle, but I hope I have offered some small insight in how the different doctrines should be used :) If you have any questions about more technical game mechanics, feel free to ask!

Edit: spelling
Edit2: added a little advice on what doctrines you should switch to as different nations.