Vulnerability Question

[Beerdsly]

If you have a weapon that applies a stack of 1% XXXX vulnerability on hit (fire, for example), and the enemy is immune to that damage, does it have no effect? My assumption is that is the case. But if not, and they are temporarily vulnerable to that type of damage, how does the math work? Are they temporarily open to take just 1% damage, or...?

I tried testing a cold vulnerability weapon on the abbot in MoD to find it has no effect, but I wasn't sure if this was a function of him being a purple named enemy or not.

Thanks!

[Xgya]

Most forms of the immunity bypass work that way - against an enemy you should be doing no damage, deal normal damage instead.

So an enemy that's normally vulnerable to fire would still receive more damage from fire.
If that enemy would be immune, but you tacked on 20% vulnerability, your damage against it would be 0x1.2, so 0. The immunity bypass activates, and you instead deal normal damage.

[Beerdsly]

If that enemy would be immune, but you tacked on 20% vulnerability, your damage against it would be 0x1.2, so 0. The immunity bypass activates, and you instead deal normal damage.

I'm confused by what you're saying. I understand that an immune enemy with 20% vulnerability damage would be 0x1.2 = 0, so by that you mean immune enemies are still immune. But the immunity bypass? I guess that's the heart of my question - does vulnerability then cause immunity bypass? Thanks in advance for the clarification!

[GeoffWatson]

But the immunity bypass? I guess that's the heart of my question - does vulnerability then cause immunity bypass?

No.

[cru121]

I recall reading somewhere that all different types of vulnerability are in fact the same effect.
5 stacks of vuln = +5% to all incoming damage.

I never bothered to test this.

Of course, if an enemy takes 0 damage, with 5% vulnerability is 1.05 * 0 = 0.

[Beerdsly]

No.

Thanks, GeoffWatson. This is what I assumed, however have not been able to confirm.

So what are sources of immunity bypass? I know Tiefling's racial ability Improved Scorch does so. (Description: Enemies affected by your Scorch spell increase Fire damage that they take by 5%. When cast on a creature that is immune to Fire, it makes them vulnerable to that element for a short period of time.) Does anyone else know other immunity bypass options?

[cru121]

Does anyone else know other immunity bypass options?

Tieflings have Improved Scorch.
Sorcs have 2 things (single-target in t5, universal in capstone)
Druids have level 9 spells (Anger of the Noonday Sun/Mantle of the Icy Soul)
Wizards have Unholy Avatar for negative damage vs undead.
Artificers got the clumsy on-runearm-blast immunity removal.