Searching for passive ability

Is there a passive ability that reduces damage of all attacks (normal, pierce, spells, magic..) by a percent?

I think there is, I think it's one of the night elf abilities... Elune's Grace or something.

EDIT!
If this helps clear it up, it has an icon which is set at night time with blackened trees and it's sorta looking up at the sky into the stars and moon.

No elune's grace works only for piercing and magic damage.
It would be nice if there was such ability for other damage types...

As far as I know, defend is the closest thing you'll get. Even then, Elune's Grace is seemingly a passive defend.

So I don't think you can get too much closer, though there is a possibility I may be wrong.

erm, how about increasing armour, that reduces damage by a percent...

If I remember, hardened skin can be changed to affect damage types like melee or piercing.

Then for spells there is a spell resistance amulet or braceless thing, I don't really remember it.

I don't know if this spell damage reduction works on magic attack types as well.

For spell damage i would use 'Alsr' (Special/Items)
and for normal damage you could try using 'AUts' (Undead/Hero).
For the 2nd i don't really know if those fields work correct, so you have to try it.

Yeah Hardnened Skin and, i believe, Spiked Carapice both have fields that should allow for a flat % reduction. Whether they work correctly though...

Hardened Skin only goes as far as melee/ranged specifications...

There's always the complicated and tedious process of triggered damage reduction, it it's honestly very tiresome, complicated, and delicate to work with.

It is not that hard. It's 2008 there are already are thousands of premade libraries for damage detection.