The latest change to Spectrum Shield

Can someone explain to me what that change means? Maybe with some concrete example with others damaging reductions skills.

"The damage reduction of this skill now stacks multiplicatively with other damage-reducing effects instead of additively."

Is it a nerf?

P.S. The text of the skill in game says it reduces by 50% only condition damage and not power damage, not a big deal but cool if get corrected and updated.

I'm going to use revenant as an example, but it should still work for engi.

Protection: 33% reduction (66% damage)Rite of the Great Dwarf: 50% reduction (50% damage)

Imagine they're both on you.

Additive: 83% reduction total (27% damage) obtained by adding 50% and 33%Multiplicative: 66% reduction (33% damage) obtained by multiplying 66% and 50%

The game uses a multiplicative system for a good reason. An additive system can easily reach a point where you'll take 0 damage. But, a multiplicative system can't.

@"whoknocks.4935" said:Can someone explain to me what that change means? Maybe with some concrete example with others damaging reductions skills.

"The damage reduction of this skill now stacks multiplicatively with other damage-reducing effects instead of additively."

Is it a nerf?

P.S. The text of the skill in game says it reduces by 50% only condition damage and not power damage, not a big deal but cool if get corrected and updated.

As @Blood Red Arachnid.2493 said, it's a big difference mathematically.

Additive damage reduction theortetically allows you to obtain temporary invulnerability -- you could theoretically stack over 100% DR with the right set of equipment, skills, and traits if they were additive. Multiplicative simply means that you will never reach 100% DR without a skill or trait explicitly stating that you can do so.

You can do some simple math for an easy analogy:

Subtractive/Additive Damage Reduction: Initial Damage is 100.

100 - 50 (Spectrum Shield) - 33 (Protection) - 12 (Iron Blooded) = 5 damage. You take 5 damage in this case if they are additive/subtractive damage reduction.

Multiplicative Damage Reduction: Initial Damage is 100

100 x 0.5 (Spectrum Shield) x 0.66 (Protection) x 0.88 (Iron Blooded) = 29 damage. You take 29 damage in this case from a multiplicative/dividing damage reduction.

In all scenarios, additive damage reduction is way more powerful than multiplicative. Thus, this is a nerf.

@Vagrant.7206 said:

@"whoknocks.4935" said:Can someone explain to me what that change means? Maybe with some concrete example with others damaging reductions skills.

"The damage reduction of this skill now stacks multiplicatively with other damage-reducing effects instead of additively."

Is it a nerf?

P.S. The text of the skill in game says it reduces by 50% only condition damage and not power damage, not a big deal but cool if get corrected and updated.

All clear.

So if let's do a real example of what I use:

I use -10% damage food plus the holo mode trait -15% damage. And that's a 25% clean damage reduction because it stacks additively.If i pop spectrum shield will be:75*0.5 = 37.5 damage taken100 - 37.5 = 62.5% damage reduction

If I have protection on will be:42*0.5 = 21100 - 21 = 79% damage reduction

So your example of multiplicative is wrong:If you have protection and iron blood with 12% will be:100 - 33 - 12 = 55 (because they stack addictevely)So if you pop spectrum shield having protection and iron blooded at 12% will be:55*0.5 = 27.5100 - 27 = 73% damage reduction

So you don't take 29% damage but you take 27.5%

But probably you were just explaining me how multiplicative works.

Every single damage reduction is calculated addictevely, food traits and all and only for spectrum shield you have to multiply.

You won't reach 100% anymore but i think you still can go really go close to it.

@whoknocks.4935 said:

@Vagrant.7206 said:

@whoknocks.4935 said:Can someone explain to me what that change means? Maybe with some concrete example with others damaging reductions skills.

"The damage reduction of this skill now stacks multiplicatively with other damage-reducing effects instead of additively."

Is it a nerf?

P.S. The text of the skill in game says it reduces by 50% only condition damage and not power damage, not a big deal but cool if get corrected and updated.

I believe the majority of damage reduction skills/traits in the game are supposed to stack multiplicatively (with the exception of skills like endure pain). Spectrum shield was weird in that it worked additively.

I don't know if food or utility items stack additively or multiplicatively.

@Vagrant.7206 said:

@whoknocks.4935 said:

@Vagrant.7206 said:

@whoknocks.4935 said:Can someone explain to me what that change means? Maybe with some concrete example with others damaging reductions skills.

"The damage reduction of this skill now stacks multiplicatively with other damage-reducing effects instead of additively."

Is it a nerf?

P.S. The text of the skill in game says it reduces by 50% only condition damage and not power damage, not a big deal but cool if get corrected and updated.

Ah ok, I though everything stacks additively and they setted spectrum shield to multiplicatevely to "nerf" without completely destroying it.

I think they stacks additively, for example the trait in Tools which gives you 10% more damage while under vigor, and the trait in Holosmith 15% more damage when above 50% heat, that should be a clear 25% damage boost you have, so maybe it works the same with food and traits like iron blooded or light density amplifier.It's all a big obscure, in fact it's the first time I heard about this different between additive and multiplicative XD So who knows how every single interaction works.

@whoknocks.4935 said:

@Vagrant.7206 said:

@whoknocks.4935 said:

@Vagrant.7206 said:

@whoknocks.4935 said:Can someone explain to me what that change means? Maybe with some concrete example with others damaging reductions skills.

"The damage reduction of this skill now stacks multiplicatively with other damage-reducing effects instead of additively."

Is it a nerf?

P.S. The text of the skill in game says it reduces by 50% only condition damage and not power damage, not a big deal but cool if get corrected and updated.

Yeah, for some reason ArenaNet rarely explicitly states what's additive and what's multiplicative. The general consensus is that most things are multiplicative, but there may still be cases of additive DR.

afaik basically almost everything stacks multiplicatively. Damage amplifiers as well as damge reducers. So if you have a 10% dmg boos from Vigor, a 15% dmg boost from Lasers edge, 5% dmg boost from sigil of force and 10% dmg boost from Scholar runes that makes a total amplification of 1.1x1.15x1.05x1.1 = 1.46 -> 46% more dmg and not an additive 40% more dmg.Same goes for damage reducers, it is always multiplicatively.In case of dmg amplifiers, multiplication is a boost and in case of dmg reducers, multiplication is a nerf.In my opinion, it makes complete sense that spectrum shield and all other dmg reducers/amplifiers stack multiplicatively. After all, you also have power, precision and ferocity multiplied (for crit dps) and you have toughness scaling by Division, so the Major part of damage calculations are done by multiplication.