Gain % damage as Extra Damage

Did anyone test this and how exactly does it work?

We know so far that they deleted double dipping mechanics that used to work in poe1. For example cold conversion tornado shot, would multiply phys damage then convert to cold and multiply again.

I saw some people say that this is pure extra % damage. A 30% extra damage on top of your 100% damage, (30% more) would be insanely strong and overpowered mod, and it clearly does not work this way.

The tooltip is the most confusing part of the maths, it shows a very insignificant boost in DPS, from gain % as damage.

I think when I had 20% gain cold damage, the tooltip only had about 1% cold dmg total.

It's just like more damage only it's calculated after everything. Actually quite strong which is why it's 2 pts of ascendancy for blood mage.

Gain as extra should work the same as conversion, except the converted part doesn't get deleted afterwards.
It should essentially equate to a more multiplier, assuming all damage types being equal. I can't tell you about your specific example, though.

My understanding is that it applies to base damage (before more/increased modifiers). If you have multiple sources of "as extra damage", they are additive with each other, because they apply to the same base damage.

Unfortunately it's hard to check in game with multiple sources, because most of these supports are conditional, they don't show the damage boost in skill details screen.

"

ImMobile2010#0431 wrote:

It's just like more damage only it's calculated after everything. Actually quite strong which is why it's 2 pts of ascendancy for blood mage.

This is clearly not the case, if you get 50-60% extra damage as another element on a wand, it does not magically doubles / 1.5x your dps.

The most likely case is that another element damage takes in no multipliers from your tree/skills, because it is another element.

But then even gain damage as more lightning damage, does not show me a full on multiplier level of dps.

When I have a wand with 15% extra damage as lightning, that does increase my dps about as much as I'd expect.
Of course the extra damage doesn't benefit from your modifiers to other damage types, it only benefits from modifiers to that extra damage.
So if you have +200% cold damage, and 10% extra lightning damage, it won't be a lot of lightning damage.
It could obviously be something else, whether it's some calculation you#re not privy of, something you haven't mentioned, or a faulty tooltip.