It's not additive. If it were, you would do less damage with Void vs hoto w/ conc on. His testing shows that Void is still slightly stronger than hoto w/ conc. on which tracks with +magic dmg% being multiplicative. I showed my calculated numbers above.

still, both numbers you guys came up with are less than what it would be if it was multiplicative, but just slightly more than what it would be if it was additive....

at 14,505 dmg, if I drop 1 all skill I go down to 13,886
if +15% magic was multiplicative, I would then go back up to 13886*1.15‎ = 15 968,9

15969/14505‎ = 1,101

That’s a 10.1% increase (if it was multiplicative)
Way more than the 3% or 1.9% you came up with

If I use your example...
lvl 35 BH, 30 conc
total max hammer dmg = 9161
if I remove 1 all skill = 8662
then if we add a multiplicative +15% = 9961
9961/9161= a 8.74% dmg increase
but you say 3%

If the numbers shown on maxroll are correct, then its multiplicative.
But if your numbers are correct, then it's not.

I am too dumb to fully understand all that.
I mean I think I understand but nothing concurrs to what I, or you, expect to happen, so it feels like I don't seem to fully understand the depth of all that.
I will stick to look at what my displayed dmg is ingame and call it a day

Edit : on the "less than if it was multiplicative but more than additive",
The answer to all that isnt it just that either the +magic% dmg is either applied prior or after conc ? Or that it is half before and half after (makes no sense but well) ? Or is it just what you guys say with 'multiplicative' and 'additive' ?

Edit 2 : tomorrow I will put my exact build on Maxroll (or at least what matters ie SKs and magic dmg) and see if it is the same as what I see ingame. This might help to understand if the planner is correct or not on these calcs.

This post was edited by Azomon on Mar 4 2026 02:58pm

He has a 10% void, not 15%.

Your math is very wrong.

HOTO
Level 35 hammers = 398 Avg + synergy = 2627 dmg + 495% Level 30 aura = 9128 dmg
Void
Level 34 hammers = 384 Avg + synergy = 2534 dmg + 10% = 2788 dmg + 480% Level 29 aura = 9479 dmg

3.8% increase

If Void was additive:
Level 34 hammers = 384 Avg + synergy = 2534 dmg + 10% + 480% level 29 aura = 8870 dmg or a 2.8% dmg loss

His char sheet shows an increase, so it's obviously not additive.

My hammers arent lvl 35 and my conc isnt 30 either tho

The levels don't matter, it's just to show the % change, directionally. Give me your hammer/conc aura levels and I can calc it directly.

The order of operation does not matter here as we're looking at 2 consecutive multiplications.
2*10*5=100
2*5*10=100
Like in the example I took from AltonBrown
lvl 35 BH, 30 conc
without any +% magic dmg it results in 9161 max dmg
remove 1 all skill, you get 8662 max dmg
then no matter if you add the +15% before of after the bonus from conc, it results in 9961 (if its multiplicative).
9961/9161*100-100=8,733%
but if he gets +3% in game, then I really can't figure out how it is calculated, but this would mean it's not multiplicative (and yet, not additive either lol)
I'll need to test by myself in game when I get time, cuz those numbers don't make sense right now...

ahhh, well, my numbers were not wrong, we were just comparing different numbers (your example didnt specify 10% magic, and I specified +15% magic)
and I couldn't come to a +3% increase either, as you should get a flat 4% increase if you use a +10% void

ok, makes sense now I guess

So is there a BH/conc level at which Void becomes better or is it always better than HOTO dmg wise ?

It should always result in more dmg
nearly even if all you wear is hoto vs void, nothing else
but it should slowly scale up in favour of void as you add more and more +skills