Need clarity on the Armor Penetration value

I need help in understanding the value that armor penetration adds to the damage formula.

Taken from @Wak4863 is the following formula I read as an example:

Berserker has a damage modifier of 2.24 swinging a star metal great sword with 58 damage and 19 ap
2.24 * .07 = .1568
2.24 * 58 = 129.92
129.92 + 0.1568 = 130.0768
Swinging on an unarmored target light attack did 140
130.0768 + 19 = 140.00 with some rounding.

If I’m understanding this correctly, the 19% armor pen, added 19 damage to an unarmored target. That would mean a very high armor pen value would be insanely good if it’s adding base damage to something.

Am I missing something?

As far as armor pen, it doesn’t add damage to weapon it reduces the opponents armor value.

So if target has no armor then it does nothing. But if they have let’s say a base armor of 100, and you have 14% ap on weapon, they now have 86 armor. For the defender that rating is a reduction to damge taken in % based on Calc. Can never have 100% armor reduction. so let’s say 100 would have been a 15% reduction, and 86 is 12 %. that means your damage is 12% less than weapon Calc total.

the norm is something like weapon + str x 2.
so a weapon of 50+ 5 str would be 110 damage - the 12 %.

How do you respond to the math based on @Wak4863 damage values that I listed above then? Clearly the armor pen is factoring into the 140 total.

Secondly, I’m pretty sure there is a Katana that the red mother drops that does 100% armor pen.

Yeah just confirmed Blade of the Seven winds had 100% armor pen.

I’ve got a suspicion (though you would need some of the folks who’ve gone more in depth on the numbers to be able to confirm) -
if you go back to the original damage calculation, it makes one big assumption - that 130 + 19 rounds to 140. If it was 150 I might believe it, but 140 feels unlikely to come from the ap. But there is another candidate - every swing in a combo has its own damage modifier (which is why, if you perform a full combo, each strike does a different amount of damage) (I learned about this from some PVP guys, but I don’t remember any of the numbers). So, if the strike being tested had a damage modifier of around 1.08, that would then take 130 to 140, without ap being a factor (which would be how it should be…)

As for how AP works - the following is pure speculation, but I feel it makes sense with the data we have -
Armour (+agility bonus etc) provides an ‘Armour Value’, this then translates to provide an armour percentage., rewarding on a curve, so as the Armour value gets higher, the percentage increases more slowly. Armour percentage is then the amount that the damage is reduced by (so a strike that would do 100 damage, striking a target with 60% armour would only do 40 damage). I think armour penetration reduces the ‘armour value’ by the relevant percentage (so, for example, 1200 armour, hit by 50% armour pen, would reduce to 600 armour) - this reduced armour value then gets turned into an armour percentage in the same way as normal, and reduces the damage by that new percentage (so in the example, 1200 armour giving around 80% protection would have been reduced to 600 armour giving around 65% protection - very rough estimates, I haven’t checked these numbers, just trying to illustrate what I mean).

As I said, I haven’t tested or proved any of this, but it makes sense to me, and is the only way I can come up with that these different values could logically interact.

Edit: I should add - I’d love some actual clarity on some of this - my speculation is all well and good, but facts would be more useful :wink:

Armor Pen used to reduce armor. So 20% Armor pen against 100 Armor would’ve treated it like 80 armor. Or 28% DR became 24% DR.

Now it reduces Damage Reduction Directly. So 20% Armor Pen against 100 Armor reduces the DR from 28% to 8%. This change happened sometime before or right around the launch of Siptah. I’m not exactly sure.

You all can test this in game, Damage Reduction = Armor / (Armor + 250). And just use admin commands to set dmg of a weapon to 100 and set Armor Pen equal to the Damage reduction (There’s a video floating around) of the test target. You can enable building damage and PVP and attack your own spawned thrall.

But for some quick and dirty values. ~80% is about the cap in PVP vs heavy Armor. ~50-60% is the cap for most heavily armored stuff in PVE.

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So in PVE, it seems like an absolute must to have some sort of Armor Pen as that massive reduction seems amazing. (28% > 8% is a huge leap).

I’m thinking specifically of Battle Axes which a lot have 0%, I notice I don’t quite hit things as hard when I’m using them. Would I generally want to craft a battle axe using a T4 Edgesmith to get the Armor Pen up a lot? Then using the Master Weapon Fitting for the damage and pen?

You do NOT want to use an Edgesmith with Battle Axes.

0% * 23% = 0% bonus

Edgesmiths give a 23% bonus to Armor Pen, so if its a 20% Armor pen weapon it will give an extra 4.6% for t total of 24% (I think it rounds down, but not sure how rounding works with that). And 0% gets nothing.

Your best bet with Axes is to use a Master Weapon Fitting for +5 Damage and +12 Armor Pen. That will give them at least 12% Armor Pen which is better than nothing. And then use a Bladesmith to get the damage as high as possible when crafting them.

Axes in general are normally not great against the heaviest armored NPCs.


Thanks for the info.

Yeah I actually just got the Grandmaster Weaponsmith from Vault chests on Siptah and was really happy so now I just need to re craft some of my weapons.

I like running around with a lot of different weapons on Siptah, right now using Axe of the Fiend, Greatsword of the Fiend, Daggers of the Great Wolf and the Voidforge Gladius.

In general should I try to get close to 30-40% armor piercing for “regular” weapons and get a high armor Pierce weapon for like Rockslide and other high armor bosses?

Sounds like a decent setup.

I tested various weapons with the Hosav UI mod, so I could actually see the amount of damage done. It turned out that on a blue skeleton, 5 points of armor penetration is approximately equal to 1 point of weapon damage. Obviously, for more armored creatures like rhino or rocknose, the ratio would be different.

That just means 100% that you have no armor as the opponent.
Wak is right in damage total…but again AP only adds if the opponent has armor.

And almost everything except players start with a base, some as low as 40.

The experiments I did with ot held up.
on sp I created 3 thralls and put armor in them. I looked at rating and then using my stats got the armor reduction percentage. then "left clan’ so the thralls were not friendly. I then attacked each one and noted the hp damage using 4 weapons. 2 1h axes 0 ap and then the same ones modified with 12 %. Math held up.

At the time of making the video there was a bug that added the damage from AP to an unarmored target. But it went away quietly.

There are very few targets in the game that have zero armor.

As for what to go after to defeat the PVE content with ease status effects are really where it’s at as those deal 100% of their damage regardless of armor. So bleed and poison are very helpful.

Lastly if it’s an axe you’re after you want the ancient Lemurian axe because of the natural AP it has and the boost in stats when crafting with a thrall.

However in all my tests on the Best blacksmith to use it was the bladesmith the raw damage number is better the the added ap from the edgesmith.

As for the math above it was reverse engineered through my testing and not the actual mathematical equation that Funcom uses. So it may be lacking some things that Funcom calculates.


I am sorry for making you repeat the things you just said but I want to understand something here.
I always use feroxic war axe (1h)
Is it wrong that I use armor pen upgrade on it, or you mean something else.
Thank you for your patience.

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Armor pen upgrade on an axe should be fine (that adds armor pen).

It is the Edgesmith (blacksmith that gives best armor pen) that doesn’t work (because they multiply the existing armor pen of the weapon, so since axes have zero, they do nothing for them).

(Except Ancient Lemurian Axe, because that does have armor pen, so an edgesmith could improve it - though, as Wak explained, bladesmith is still better.) :slight_smile:


You’re good. Using kits gives a flat bonus that adds.

The bonus from Edgesmith is multiplicative.



Oh, so you suggest me not to use edgesmith for crafting axes correct?
One last question please, who is the best blacksmith for crafting axes, thank you in advance

As with what other had say use a Bladesmith as most weapon don’t have that high of base armour pen that will have a noticeable increase when using Edgesmith.


Wrong. Armor pen (AP) gets subtracted from the enemy’s damage reduction (DR).

If the enemy has 60% DR, then a weapon with 14% AP will bring the enemy’s DR down to 46%.

Use a Bladesmith. Always.


No it is a % reduction. If subtracted, then you would get -% if a player as let say 5% damage reduction. I have tested and the math holds up with a +/- of 2 or 3 hp.