Total Spell Damage Reduction

I did a little poking around and couldn't find exactly what I was looking for, though if I didn't poke hard enough, feel free to chastise me .

But I was looking at Steelbreaker last from 25-man's Fusion Punch, and just how hard it would hit me. It has a base damage of 35000, and once the other two members of the Assembly are down, it is increased by 50% (25% 2x) to 52500. Now, my first thought is that it is unsurvivable without cooldowns, as I cannot get much past 45k raid buffed (gg no tank loot for first month of Ulduar). But I wanted to be sure about its final damage.

Here is where I come to my question. What is our total spell damage reduction? I know some things are additive, while others are multiplicative, but I had trouble finding what had a relation to what, and in what order they worked to reduce the damage of the blow, or if all of the reductions were added/multiplied, and then that final number was multiplied against incoming damage.

But our spell damage reduction talents/skills/etc are as follows:

Talents: Improved Righteous Fury (6% all damage), Shield of the Templar (3% all damage), Guarded by the Light (6% spell damage)
Glyph of Divine Plea (3% all damage)
Other: Blessing of Sanctuary (3% all damage), Effulgent Skyflare Diamond (2% spell damage)

I believe that is everything. I heard rumors that Grace, the Disc talent, stacked with Blessing of Sanctuary, but as it is just rumors, it is not included in my calculations. I included the Effulgent Skyflare Diamond because I felt that the strength of Fusion Punch as well as the pulsing High Voltage more than justified the 2% spell damage reduction over the 2% armor.

But the problem lies in how these all add up. Do we just add everything for a 23% reduction? Or do we multiply everything for a hair under 21% reduction? Or is it some combination of the two?

Doloth wrote:Or do we multiply everything for a hair under 21% reduction?

This.

The first tank on Steelbreaker after the other two assembly members are down can take fusion punches without any cooldowns (disc priest shields are nice safeguards in any case). After that you will need cooldowns for each fusion punch.

It's worth noting that the Efflugent Skyflare Diamond doesn't work how you would expect it to.

What it actually does is increase your resistance by 2%, not reduce spell damage taken. It's pretty much the worst meta gem ever invented, to be honest.

Levantine wrote:It's worth noting that the Efflugent Skyflare Diamond doesn't work how you would expect it to.

What it actually does is increase your resistance by 2%, not reduce spell damage taken. It's pretty much the worst meta gem ever invented, to be honest.

I haven't tested it personally, but I believe it was fixed to work properly a few patches ago. I know the datamined spell effect was changed to indicate a damage reduction consistent with other similar effects. Previously, it was an increase in resistance.

The Efflugent Skyflare Diamond now works as it should, reducing spell damage taken by 2%. I tested it on Mimiron during his Plasma Blast in phase 1, as that had a set amount repeated over and over again while the cannon is engaged to you. I had the math written down somewhere, but I can't find it now, but next time I do Mimiron, I'll try to throw up some exact numbers to show you the difference between the two. I keep the Efflugent diamond in my Tempered Titansteel helm, which I use in my max stam, dragon tanking helm.

Interesting. I should see if I've still got my Titansteel helm lying around then. O:

Didn't see anything in the patch notes, so I just kinda assumed they didn't change it.