Battle tactics

[Edhelras]

Hi, I'm nearing my first completion of the game, with Ethiopia. I've reach all my personal goals and the mission tree, I've got 500K of gold and 900K of manpower. However, due to my low INT I struggle with the battle tactics. Any advice on how to understand the game better would be appreciated.

With combat width 40, I've arranged my 1000 units into 41-unit corpses (19-2-20). They usually don't incur attrition. In any pitched battle I combine 2 corpses and can see that they nicely fill out 40 cannon in the back row, and infantry and flanking horse in the front row.

However, in large scale battles, I still struggle sometimes. So a few tactical questions:

1. When my army starts getting depleted or demoralized - should I just throw in another 19-2-20 corps? Or should I rather keep around a reinforcement corps with solely infantry? As it seems frontline infantry are the ones taking the most physical and moral damage?

2. Sometimes againt a huge enemy I start taking moral damage and usually loses the battle. In those cases, it seems it doesn't help throwing in even more fresh corpses. Why is that? Should I rather accept that this particular battle is lost, and instead arrange my reserves in another province, or alternatively wait until my losing corpses are defeated, and then start a new battle with fresh corpses?

3. Is it useful to study each tiny little unit in the combat screen, to see which ones are damaged or demoralized? Can I use this to determine reinforcements? And will a damaged or demoralized unit do less damage in battle, so it would be better to get rid of it? And at what point would a damaged individual unit be removed from the frontline, to give room for reinforcements?

4. As above, should I micromanage the flow of reinforcements into the battlefield, or should I just pour reinforcement into the province and hope that it will do the trick?
Given that (I think?) poor morale will affect not only front line units, but as well any reserve units not actually placed in the battle rows - would it be ideal to have only just about 80 units (or, a bit more) in the battle province at any given moment? If I was able to steer it thusly.

5. I've a problem understanding the battle phases in relation to days - is there a rule of thumb for at which day reinforcements ought to arrive on the field? With forced march and game speed 1, I think it might be possible to finely decide exactly when reinforcements are to arrive on the field, if keeping track of the days is useful.

Another question:
6. I've understood that infantry are the most important in the end-game. However, is that only because cavalry are more expensive? Or are infantry actually better, independent of costs? It seems that level 28 infantry have exactly the same total pips as level 28 cavalry - does that mean they're equally powerful, or do infantry or cavalry have any other strengths/advanteges besides number of pips?
(At level 30 infantry gets one more pip than the best cavalry, so I guess that at that level infantry is preferable?).
(I don't know much about the different ideas and other features improving infantry or cavalry that might play into this, maybe this question depends on which kind of unit gets the most additional benefits?)

[Kapika96]

1. Yeah, not really much point having armies with just infantry around (unless it's very early game) so just throw another army in.

2. Don't worry too much about morale damage. What are the casualty figures? They're more important. If more of their troops are dying than yours, then send in an extra army to get your morale back up and you could win the battle. If your side is losing more troops, it might be better to just retreat your army. Not to a nearby province either, you want to retreat far enough away that they have time to recover morale/reinforce losses.

3. No, it's not. There's not really much you can do there specifically, and really you should have more important things to do than monitoring individual units in battles.

4. Generally, no. It could give you an edge, so if you're playing competitive MP or something it might be worth it. But if you're just playing for AI there's no need, just pile your troops into the battle. Worth mentioning that at high army professionalism reserve troops suffer reduced morale damage too.

5. If there are gaps in your front/back line then you want reinforcements ASAP, especially if there aren't gaps in the enemy's formation.

6. Artillery are the most important, by far. They are better than cavalry though, yeah. Unless you have boosts to your cavalry it might be worth omitting them completely and just going full inf/art. Cavalry have advantages to shock damage and flanking. Fire damage is more important, since the fire phase comes first in battle and the flanking advantage means less late game when infantry can have 2 flanking as well. Plus artillery have as much flanking range as cavalry too.

Early game cavalry are better than infantry. Although still worth mentioning that infantry is more economically efficient. You can probably afford 3 infantry for 1 cavalry and 3 infantry is the better choice there. But they can be the difference in battle so if you have the cash and need an advantage they're good. Same as above, if you have cav boosts for your nations then they can be even more useful. Like hordes that can go 100% cavalry really should!

Also FYI corpses = dead bodies. It might be better to say armies instead.

[Edhelras]

Thank you!
In my case, the armies unfortunately ended up as corpses, so actually that turned out to be the correct term....

I do have high professionalism (100 %). So that will reduce the morale damage on reserves-in-waiting?
I've read different things about professionalism, but in this game, I tried staying away from mercenaries except from the very beginning of the game, and have been drilling constantly trying to have 100 % drilled armies and ever-increasing professionalism. It's something of a hassle, checking on the drill status of all armies, and it seems I'm more prone to losing valuable generals during exercise? (So I did try to use the poorest generals for drilling, and sometimes they got an extra pip from it.). Also, I feel it makes me more vulnerable and less flexible, if something pops up close upon a drilling army with low morale.

But is all this drilling and professionalism really worth it? I liked it from a role-playing aspect, and generally I felt my armies were strong and well-performing. But I'm not sure if it was worth the trouble (and does it cost me anything?). I notice that my vassals generally did drilling, so I thought it was a good idea for me too.

[Kapika96]

Originally posted by Edhelras:

Thank you!
In my case, the armies unfortunately ended up as corpses, so actually that turned out to be the correct term....

I do have high professionalism (100 %). So that will reduce the morale damage on reserves-in-waiting?
I've read different things about professionalism, but in this game, I tried staying away from mercenaries except from the very beginning of the game, and have been drilling constantly trying to have 100 % drilled armies and ever-increasing professionalism. It's something of a hassle, checking on the drill status of all armies, and it seems I'm more prone to losing valuable generals during exercise? (So I did try to use the poorest generals for drilling, and sometimes they got an extra pip from it.). Also, I feel it makes me more vulnerable and less flexible, if something pops up close upon a drilling army with low morale.

But is all this drilling and professionalism really worth it? I liked it from a role-playing aspect, and generally I felt my armies were strong and well-performing. But I'm not sure if it was worth the trouble (and does it cost me anything?). I notice that my vassals generally did drilling, so I thought it was a good idea for me too.

IMO professionalism is definitely worth it. It gives a number of benefits, see the wiki for full details, but one of them is a -50% reduction to morale damage for reserves at 80% or above. https://eu4.paradoxwikis.com/Army#Army_professionalism

The main benefit to mercs is using a separate manpower pool. That's definitely useful early game, if you've got the money for it getting a merc army ASAP is usually worthwhile. But late game you often have more than enough manpower with regular armies alone that they're not as important. I know some people still rate them highly, and with certain nations/ideas they probably still are good late game.

Drilling isn't as worth it. It actually gives more benefits at 100% than professionalism, but takes a while to get to 100% and will start dropping as soon as you stop drilling. It's nice for a boost to your armies, but late game it's not too important. You're probably going to have more armies than generals by that point anyway so can't drill them all.

Drilling doesn't cost any more than regular army maintenance. Drilling does make them cost 100% even if you lower army maint costs though, so if you need to save money/repay loans and want to lower army maint to do so then drilling will impact that.

As for drilling armies being vulnerable, keep them away from the front lines or high unrest provinces when drilling. Enemy armies should be blocked off by forts anyway so you'd have a chance to recover morale before they need to fight.

[Edhelras]

Thank you!

[BlueBangkok]

1. Combat Width - if you are high mil tech, I would put more cavalry in the front row. Late game cavalry is very good, and does devastating damage in shock phase. The only limitations are costs and flanking range. Ideal army for CW40 is something like 40 infantry, 8 cavalry, 40 artillery. Basically, you want the full back line of artillery and a little bit more than full front line of inf+cav in each army that is fighting, to ensure maximum damage to the enemy and some trickle of reinforcements to the front row.
Note that the ratio of inf and cav can be different depending on your nation - what I wrote is applicable mainly to Western European armies, as I haven't played in Africa. If you have modifiers to cav combat ability and/or flanking range, you might want to increase cavalry ratio even more.

2. It's probably because weaker units like artillery start dropping into the front row, getting killed, which in turn increases morale damage. The longer the battle takes and the more soldiers are killed the quicker you lose morale. Leaders also play a huge role - generals with high fire and shock stats will often win battles that are close in numbers, unless they get extraordinarily unlucky with dice rolls.
Also, be sure to check the enemy nation's ideas and tech. If they are mil tech above you and they have better military ideas, you will need to overpower them with very high numbers. You should see stats such as their tactics, discipline, in the battle window.

3-4. Reinforcements will boost your morale, so the only micro management you need to do is to ensure that your fighting army is properly reinforced in time to get morale boost and not lose before the reinforcing army reaches them.
If you really want to micro the war, you should build tons of backup regiments, mainly inf, then immediately after a battle consolidate regiments in your main army and reinforce to the 40-8-40 ratio from the backup regiments. But I don't usually bother with this against the AI.

5. No. Not that useful. Just reinforce before you lose. If the battle is close, reinforcements should tip it in your favor. But see point 2, you will need many more troops to overpower enemies that have superior stats.

6. See 1. Cavalry is very strong at mil techs 26+. They are also quite strong the entire game, it's just that they are more than double the cost of inf regiments and not x2 stronger, thus not usually worth it to use en masse, unless you are a Horde or have tons of cav bonuses.
As for units pips - it really depends on you which types of units to prioritize, I don't think there is a wrong answer here.
Cavalry has much higher shock pips than inf. For example, at tech 28, impulse infantry has 3 offensive shock pips. Latin lancers have 6 offensive shock pips. That means during offensive shock phase, the cavalry will inflict much more damage. To calculate how much more, please see the Wiki - Land Warfare formulae; assuming enemy has 3 defensive pips and everything else (leaders, terrain, dice roll, tactics, discipline...) is identical, it should be double the damage of infantry in base casualties.

[dbond1]

Professionalism and drilling are both worth it in my view, as they are 'free'. There are potential pitfalls to drilling, as mentioned above. You need the room to do so without undue peril to the drilling stack. And it is rather a luxury, affordable only to those nations with plenty of downtime. Some runs just don't give you the time, like when you are Emperor and stamping out heresies, or any sort of run where you are fighting on all fronts, all the time. But if you have the time and security to do it, it's worth it especially considering there is no cost.

Few AI nations reach high professionalism, so the player will almost always have an advantage here, and we want as many of those as we can get. There's a government reform that will let you drill faster and retain the effects longer, if that might be appealing. I just used it in my Adal Golden Horn run and yeah, you can go years with the drill bonuses so that was cool.

[BlueBangkok]

Originally posted by dbond1:

Professionalism and drilling are both worth it in my view, as they are 'free'. There are potential pitfalls to drilling, as mentioned above. You need the room to do so without undue peril to the drilling stack. And it is rather a luxury, affordable only to those nations with plenty of downtime. Some runs just don't give you the time, like when you are Emperor and stamping out heresies, or any sort of run where you are fighting on all fronts, all the time. But if you have the time and security to do it, it's worth it especially considering there is no cost.

Neither is free. Professionalism costs money or mil mana, drill costs money. Prof. is great, because it doesn't tick down.
Drill itself, however, is not worth it, imho. Not because it's expensive as you are paying full upkeep, but because it ticks down waaay too quickly. I still do it, because there's simply nothing else to do later in the game unless I want to hoard ducats for something, but the moment you stop drilling, recover morale, and go fighting / sieging, you already lost part of the drill. And you lose drill super quickly in battle or attritioning. You will never see the full drilling bonuses in practice.

[vdarkcharlie]

I like how you use the word corpses instead of corps. Not sure if it is on purpose but in your case both apply.

[red1]

I know that the common wisdom here is that military ideas are less than. However, more than once I have beaten countries (aka Ottomans) with armies half the size. The main reason, quality of my troops. High morale, discipline, well drilled, and the military quality group. Everyone has their on style of play. I for one, have never taken the Admin group. I am over 14K hours playing now.

[Marquoz]

You can of course play any way that works for you. But if you want to get some of EU4's hardest achievements, playing without groups like Admin is like trying to run while wearing cinder blocks on your feet.

The advice we give here is designed to be the strongest, most efficient, and easiest approach to the game. Other ways can work, but new players who find the game too difficult need to follow the path of least resistance, at least at first. Blobbing efficiently outstrips all other single player strategies by a very large margin and therefore is that path.

[Kapika96]

Originally posted by BlueBangkok:

6. See 1. Cavalry is very strong at mil techs 26+. They are also quite strong the entire game, it's just that they are more than double the cost of inf regiments and not x2 stronger, thus not usually worth it to use en masse, unless you are a Horde or have tons of cav bonuses.
As for units pips - it really depends on you which types of units to prioritize, I don't think there is a wrong answer here.
Cavalry has much higher shock pips than inf. For example, at tech 28, impulse infantry has 3 offensive shock pips. Latin lancers have 6 offensive shock pips. That means during offensive shock phase, the cavalry will inflict much more damage. To calculate how much more, please see the Wiki - Land Warfare formulae; assuming enemy has 3 defensive pips and everything else (leaders, terrain, dice roll, tactics, discipline...) is identical, it should be double the damage of infantry in base casualties.

Mil tech 26+ is actually one of cavalry's weakest points. IIRC the only time cavalry is weaker (for Western tech group) is at mil tech 9 (since infantry gets a new unit, but cav has to wait until tech 10).

It will also never actually do double the damage of infantry like you're saying. Damage is multiplied by remaining troops/total troops and the fire phase always comes first. Inf having 3 or 4 defensive fire pips compared to cav having only 1 or 2 mean they'll always suffer less losses in the fire phase, so cav will have a larger reduction to damage in the shock phase from losses than inf will.

IIRC at those tech levels cavalry will actually suffer more losses than infantry due to worse defensive pips too. It's more likely to win the battle, but it will suffer more while doing so.

Don't get me wrong, 1vs1 cavalry is still better than infantry then, it just seems misleading to say it's "very strong at mil techs 26+" when it's actually stronger at nearly all the techs before that.

[BlueBangkok]

Originally posted by Kapika96:

Mil tech 26+ is actually one of cavalry's weakest points. IIRC the only time cavalry is weaker (for Western tech group) is at mil tech 9 (since infantry gets a new unit, but cav has to wait until tech 10).

It will also never actually do double the damage of infantry like you're saying. Damage is multiplied by remaining troops/total troops and the fire phase always comes first. Inf having 3 or 4 defensive fire pips compared to cav having only 1 or 2 mean they'll always suffer less losses in the fire phase, so cav will have a larger reduction to damage in the shock phase from losses than inf will.

IIRC at those tech levels cavalry will actually suffer more losses than infantry due to worse defensive pips too. It's more likely to win the battle, but it will suffer more while doing so.

Don't get me wrong, 1vs1 cavalry is still better than infantry then, it just seems misleading to say it's "very strong at mil techs 26+" when it's actually stronger at nearly all the techs before that.

It should do double *base* casualties damage, which then gets multiplied by remaining troops, morale, etc., etc., in reality it won't be exactly x2, of course, because there are just too many factors. I said that in a very misleading way.

As for cav pips, depends... the area where cavalry is lacking are fire pips, but tech 26+ cav has the same defensive shock pips as infantry has, but double or almost double offensive shock pips. They suck in the fire phase, that's why the overall pips seem weak compared to infantry. Also don't forget about the extra flanking range late game tech gets, which makes cav more useful.

OP's army comp with 2 cav is actually decent, I would have used more than that, but it's probably not the reason why he's losing close battles.

[RCMidas]

Consider this: taking less damage initially means you can inflict more damage with your retaliation, which means your enemy deals less damage afterwards AND you resist it better, which then snowballs into you inflicting WAY more damage on them, which means...

And it just goes on and on and on. All else being equal, those defensive pips being lower for cavalry mean they will swiftly die quicker than infantry. The only time late-game cavalry are really useful are when you have specialised "sniper" armies for engaging smaller enemies so as to make use of cavalry's larger flanking ability. Given that that is so ludicrously situational outside of perhaps finally assaulting a Balkanised HRE with 70+ OPMs, not exactly worth it.

[Mr.M]

The one and only way to build armies is to go 100% cannons.

Not 20/0/20, not 16/4/20 but 0/0/40. Found that out only recently

[Edhelras]

Thank you all for very, very useful advice!