For example, the Agonizing Flames talent for Blackwater Cocktail. It reduces resistances by 25 when maxed. How good is this 25? Will it scale well or do you just want to focus on %resistance shredding instead?

Also if Blackwater Cocktail just isn’t worth taking at all generally then that’d also be nice to know.

Multiplicative resistance reduction is generally a lot worse than flat resistance reduction. It comes in far too small quantities to make much use of it except for damage types like Vitality.

Additive resistance reduction, like that on BWC, is solid. You usually won’t see more than 20-35 of it in any given spot.

Having said that, BWC is still pretty trash once you hit Ultimate, or even Elite.

Still not clear and cannot find answers in Game guide/Combat…

Grimcalc says that, for instance, Fabius has
% Cold Resistance 50
% Fire Resistance 50
% Reduced Knockdown Duration 500
% Physical Resistance 20
% Pierce Resistance 20

So his resistances are in %, but what are their flat amounts?
Or % = flat amounts?

I mean:

Monsters max resists are 100 points flat (100 = immune) - yes/no?

If Fabius’ % Cold resist is 50% - means that his flat resistance is 50 points out of 100 possible;
3a) So for Fabius 20 flat resistance reduction will make his resistance 50 minus 20=30
3b) 20% reduction for him will result in 50 flat - 20%=40 flat?

So if flat reduction and % reduction numbers are the same (say, 20 flat vs 20%) - flat will always be better than %?

I’m playing Druid with Raging Tempest so this topic is vital for me

Keep in mind flat resistance reduction is always better point for point until your enemy has +/- 100 resistance. At 50 resistance it is only half as effective. If your enemy has 0 resistance after your flat reduction percentage based reduction will do nothing at all. So it is only marginally useful when you have very little flat reduction or tons of flat reduction. More ‘typical’ values of resistance vs flat reductions it is largely useless.

You have it correct worship. With the added caveat that flat reduction is always applied first.

So if you have Raging Tempest (30 flat) and 20% from a judicator signet it would look like

(50 Lightning Resistance - 30 flat) X 0.8 (the judicator signet) = (20) X 0.8 = 16. Your percentage reduction gave you all of 4 shaved off your enemies resistance.

If it goes negative…

(50 lighting resistance - 30 (raging tempest) - 30 (arcane bomb) X 1.2 (percentage) = (50 - 60) X 1.2 = -10 X 1.2 = -12. Your percentage reduction lowered their resistances by 2.

As you can see the ‘best case’ scenarios for percentage based reduction occur when your enemy has REALLY high resistance, in which case you are best off not fighting that enemy if at all possible, or if they have really low resistance - such as the values of poison resistance Witch hunters can achieve or the vitality resistance values conjurers can achieve.

So a flat resistance reduction will cut a flat percentage? Such as in the case of 30 flat resistance and 10% resistance reduction, it’d be (50-30)*.9, or 18%?

huh, looks like something to be added to grimcalc, perhaps I missed some stats…
maybe they have flat resistances in their monster files. maybe they dont.

It depends on the wording. I often refer people to this very handy cheat sheet:

As you can see, Blackwater Cocktail is a flat resist reduction. In your example, it would cut a flat 10 away: 30% resistance becomes 20%, even if in BWC’s tooltip it does not mention a percentage; all resists and reductions work in %.
“n% reduced resistance” is the only multiplicative type of resist reduction, and the one that is usually very ineffective because of the way it stacks with the other types of resist reduction. In your example, if the resist reduction was of this type (10% reduced target’s resistance), it would turn 30% resistance into 27%.

n reduced target’s resistance can’t stack with another source of n reduced target’s resistance. The same applies to different sources of n% reduced target’s resistance.

The reason -n% resistance can stack is because it is a part of a debuff whereas reduced target’s resistance is it’s own debuff. You can’t stack two curse of frailty on one target for example but you could stack curse of frailty and devouring swarm because they aren’t the same debuff.

What Nine said.
Maybe the “flat” term is a bit confusing, imma explain how I see it:
If an enemy has 50%fire res, when u apply -30 fire res, it will reduce it to 20. But when you apply -30%fire res, it will reduce it with approx. 16.(30% out of 50).
But I might be wrong, I understood it to be this way.

[ul]
[li]30 reduced resist -> removes a flat 30% from enemy resist, which jmeans it can reduce below 0[/li]
[li]-30% resist -> same as above, but can stack with other -xx% resist[/li][*]30% reduced target’s resist -> reduces by multiplicative 30%, so you will get less than 30% reduction on the enemy unless he has 100% resist against it; also doesn’t stack[/ul]

So, for an undead, for example, who has like 500 bleed rez, from the 3 reduction types, (considering for the sake of the example that all 3 are 30), the biggest reduction will provide 30% reduce target resist? Opposite to this, an enemy with 30 bleed rez will benefit less from this 30% reduce target resist?
Sry if I bother you with all these, but things begin to get clearer in my mind, thanks to topics like this one.

You are correct about the effectiveness in your example; however no enemy in the game has more than 100% resist to anything. So multiplicative resist reduction will never be preferred to another, especially since it’s applied last.