Mid's - Weaken vs. Effective vs. Ignore Resist - Guide [3.0]



  1. Introduction
  2. The Enemy Resistance System (PvE)
    2.1 Base Resistance
    2.2 Resist, Greatly Resist and Immune Affixes
    2.3 Enemy’s Usual Weakness
    2.4 Examples
  3. Weaken
  4. Effective (Mythic)
  5. Ignore Resist
  6. Analysis and Comparison
    6.1 Crystal Weaken (compared to Ignore Resist)
    6.2 Effective (compared to Weaken and Ignore Resist)
    6.3 Arcane Damage
  7. Conclusion (the TLDR Part)

1. Introduction

It’s been some time now that I’ve been wondering how Ignore Resist, Weaken and Effective work exactly. I’ve always wondered why everybody uses Ignore Resist and not Weaken - I reckon this is because nobody really knows how it works.
I’m gonna shine some light on this, expain to you what’s what and would like to thank the boss @SteigerBox for letting me bug him about it ;).
This guide is especially important for those who want to use the new Arcanist - to understand what Weaken does exactly and how to properly include it into your build.

2. The Enemy Resistance System (PvE)

… is actually not as complicated as one might think. Because it is actually just a damage multiplication factor (your damage gets multiplied with this factor) - or a Damage Multiplier as I like to call them.

2.1 Base Resistance

In case the monster has no resistance affixes of a given element (i.e. simply no resistance against it), this factor is simply 1. That means you deal your nominal damage to it if you match the element, your damage is neither in- nor decreased; it gets multiplied by 1 and therefore stays the same.

2.2 Resist, Greatly Resist and Immune Affixes

Now Poison enemies have the affix “Resist Poison”, Shock enemies “Resist Shock” and so forth. These affixes are again simple multiplication factors:

  • Resist - 0.5
  • Greatly Resist - 0.25
  • Immune to - 0

2.2.1 Resist Affix and Immune Affix

The Resist affix is distributed to all enemies of a map. Its element is the element of the map:

  • Act 1: Poison
  • Act 2: Shock
  • Act 3: Ice
  • Act 4: Fire

That means all enemies on an Act 2 map will have the Resist Shock affix - but you will only ever see it shown on normal enemies. Magic and above enemies do also carry the Resist affix, but it is not shown. The reason for that is that they draw their other affixes out of another affix pool: The affix pool shown in the “Enemy Affixes” tab of the Dictionary.
For the same reason (different affix pool) the Immune affix can only ever appear on normal enemies. But other than the Resist affix which they always have, magic and above enemies can never become Immune.
Since there are no Arcane maps, Resist Arcane and Immune to Arcane affixes do not exist.

2.2.2 Greatly Resist Affix

The Greatly Resist affix is only available for magic and above enemies. Greatly Resist Arcane is also available in this affix pool.
Since all magic and above enemies carry a hidden Resist affix, the Greatly Resist affix can match the element of this Resist affix as well: Resulting in a combined multiplication factor of 0.5 * 0.25 = 0.125 in these cases.

2.3 Enemy’s Usual Weakness

Every enemy also has a so called Usual Weakness. Its weakness is defined by the enemy’s element:

  • Poison enemies - Shock
  • Shock enemies - Poison
  • Ice enemies - Fire
  • Fire enemies - Ice

If you happen to use the element of the enemy’s weakness, you will deal 25% more damage (neglecting the resistance affixes from above for now). This means that the damage multiplication factor becomes 1.25 for this element only - the enemy’s usual weakness is defined by this factor.
You could regard it as the base factor multiplied by the usual weakness factor: 1 * 1.25 = 1.25. Since the enemy’s usual weakness is not the element of the map you are on (see previous section), it can never be of the same element as a Resist or Immune affix.
A Greatly Resist affix however can match the element of a Usual Weakness!

2.4 Examples

Example 1:

You deal Shock damage against a Shock enemy (it automatically has the “Resist Shock” affix because it is a Shock enemy):

  • Base factor: 1
  • Usual Weakness factor: -
  • Resist factor: 0.5
  • Total factor: 1 * 0.5 = 0.5

You deal 50% of your nominal damage.

Example 2:

You deal Shock damage against a Shock enemy with “Greatly Resist Shock”:

  • Base factor: 1
  • Usual Weakness factor: -
  • Resist factor (hidden): 0.5
  • Greatly Resist factor: 0.25
  • Total factor: 1 * 0.5 * 0.25 = 0.125

You deal scarce 12.5% of your nominal damage.

Example 3:

Now you happen to deal Poison damage against a Shock enemy with “Greatly Resist Poison”. How much damage do you deal?

  • Base factor: 1
  • Usual Weakness factor: 1.25
  • Greatly Resist factor: 0.25
  • Total factor: 1 * 1.25 * 0.25 = 0.3125

So you deal only 31.25% of your nominal damage to this enemy.

If an enemy is Immune to your element, you will consequently deal no damage at all.

3. Weaken

Weaken “Gives +xx% chance to reduce enemy’s Resists by +xx%”. Unfortunately this description is still a bit misleading, and also only updated for Abyss and the epic affix (crystal affix description still not mentioning the chance part).
Weaken gives you a +xx% chance to increase your damage. How the damage is increased I will explain now.

If the enemy is weakened, Weaken is added additively upon the damage multiplication factor. Say we have 90% crystal Weaken. If it hits (90% chance), we will have:

  • Base case: 1 + 90% = 1 + 0.9 = 1.9
  • Resist case: 1 * 0.5 + 0.9 = 1.4
  • Greatly Resist case: 1 * 0.25 + 0.9 = 1.15
  • Immune case: 1 * 0 + 0.9 = 0.9
  • Usual Weakness case: 1.25 + 0.9 = 2.15
  • Usual Weakness and Greatly Resist case: 1 * 1.25 * 0.25 + 0.9 = 1.2125

as a factor; you get the picture. So we increase our damage drastically with Weaken! By how much depends a lot on the enemy we are facing.
And on its chance. If you want to use Weaken, I recommend to use at least one crystal and one epic affix/Abyss to get 100% chance. Two crystal affixes are of course a lot better, if you don’t need the second crystal slot for something else.

4. Effective (Mythic)

Effective changes your element to the enemy’s usual weakness - during damage calculation!

That last bit is the source of endless confusion. What does this mean? It means that once your damage is calculated, at the resistance step, it will change the element of your damage to the enemy’s usual weakness - and therefore giving you 1.25 as a resistance damage multiplication factor instead of 1 (before enemy Resistance affixes).

This means that if you use Ice damage, it will still slow and in case of an elemental critical freeze the enemies. Poison clouds will still spawn. Blistering, Blight, Frostbiting etc. will still work normally.

5. Ignore Resist

Ignore Resist does exactly that, it ignores the resistance part completely. So it will negate the effects of Effective and Weaken completely (they would therefore be wasted). It will also negate the enemy affixes Resist, Greatly Resist and Immune.
Your damage will always be your nominal damage - you can regard it as fixing the resistance multiplication factor to 1 in all cases.

6. Analysis and Comparison

6.1 Crystal Weaken (compared to Ignore Resist)

If you roll back a bit you will find only one number in chapter 3 which is below 1 - and it is that of Immune enemies. They are not very common, and if they appear you still deal 90% of the damage you’d deal with Ignore Resist (damage factor = 1).
Now there is of course the 90% chance bit, but even with this you will deal more damage on average than with Ignore Resist. Crystal Weaken is better than Ignore Resist!

I will even try and quantify this for you with a bit of thumb ruling…


  • We don’t use Arcane damage.
  • We don’t consider Immune enemies (they are rare).
  • We don’t consider Greatly Resist on magic and above enemies (it is also rare that they match your element).
  • 90% Weaken (10% chance to not apply Weaken).
  • 1/4 chance for Resist against your element (4 different map types).
  • 1/3 chance for your element (when it is not the Resist element) matching the enemy’s Usual Weakness.

So let’s roll:

  • 0.9 * (3/4 * (2/3 * (1 + 0.9) + 1/3 * (1.25 + 0.9)) + 1/4 * (0.5 + 0.9)) + 0.1 * (3/4 * (2/3 + 1/3 * 1.25) + 1/4 * 0.5) = 1.748

Woahh!! So you deal freaking ~ 75% more damage with Weaken than with Ignore Resist!!

Why did nobody ever tell you that? Well I’m doing it now ;). A second crystal Weaken will give you:

  • 3/4 * (2/3 * (1 + 1.8) + 1/3 * (1.25 + 1.8)) + 1/4 * (0.5 + 1.8) = 2.738

So a second crystal Weaken increases your damage 2.738/1.748 - 1 = 56.6% further; remember this is only a rough estimation and not exact - we left out Greatly Resist and Immune enemies, so it will be a bit less. It is therefore comparable to crystal Crit% and Crit DMG% which give you ~ 54.7% average damage per slot (if you combine both).

Crystal Weaken is by far the best first crystal slot. Holy Hell. Why were you using Ignore Resist again?

6.2 Effective (compared to Weaken and Ignore Resist)

Effective secures that you get the 1.25 factor. So compared to Ignore Resist (damage factor = 1) it will give you 25% more damage on average. A tad less, since you have the rare occurrences of enemies which Greatly Resist their Weakness.
Now since you don’t use Ignore Resist, you will want to use Weaken.

With 90% crystal Weaken, we get:

  • 0.9 * (1.25 + 0.9) + 0.1 * 1.25 = 2.06

Thus the damage increase from Effective shrinks to 2.06/1.748 - 1 = 17.8%. If you employ 2x crystal Weaken instead, you get:

  • 1.25 + 1.8 = 3.05

Now the damage increase from Effective has shrunk even further to 3.05/2.738 - 1 = 11.4%. As you can see, Effective is not really worth it with Weaken - the more Weaken you have, the less damage Effective gives you.

If you don’t want to use Weaken for whatever reasons, you can use Effective instead of Ignore Resist. On average, you will deal almost 25% more damage with it. There will however be said seldom cases where you deal only 31.25% of the damage you’d deal with Ignore Resist - or where Ignore Resist would deal 220% more damage (to use another way of saying it).

6.3 Arcane Damage

Arcane damage is a special case, since you don’t encounter Resist against it (except magic and above enemies) and enemies don’t have it as Usual Weakness.
In case you use Arcane damage, 90% crystal Weaken will simply yield

  • 0.9 * (1 + 0.9) + 0.1 = 1.81

81% more damage than Ignore Resist. Now that I think about it this example is much simpler than the calculation series above, maybe I should have started with this :joy:. Anyhow, Arcane has so many disadvantages (no elemental effect, bad elemental critical, …) compared to the other four elements that it is only ever used in conjunction with Arcanist and Ascendent. Where Weaken is mandatory.

7. Conclusion (the TLDR Part)

  • The first crystal Weaken is the most efficient crystal damage boost. Way more damage than Crit% and Crit DMG%.
  • You will want to have at least one slot of it, and then a second one (if you already have Crit% and Crit DMG%) or, if crystal slots are otherwise used up, get 1x Abyss/epic Weaken to trigger Weaken always.
  • If you can’t afford a crystal slot for Weaken you may have built your char wrong. In the very rare and special cases where you didn’t, you may use Effective or Ignore Resist.
  • If for some strange reason you don’t or can’t use crystal Weaken, you can use Effective or Ignore Resist. Effective will average almost 25% more damage than Ignore Resist, but in special cases you’ll deal a lot less.
  • Ignore Resist cancels Weaken and Effective; they won’t work with it.
  • Effective is not worth it if you use (crystal) Weaken. The more Weaken you have, the less effective (pun intended) it gets. You will want to have a look at the new Dauntless instead ;).
  • Crystal Weaken >> Mythic Effective > Legend Ignore Resist - just the way it should be!

For some reason I can’t edit the old thread.

Special thanks @Clogon who dueled me in the old thread until I finally understood what he meant. And needless to say he was right(ish) again :yum:.

Cheers! Mid

Weaken Affix (What,How,When, etc.)
Ignore Resist vs. Weaken & Effective Guide by Mid (as of Patch 2.5)
Need help with my War. Toss Build
Updated Wiki
Is Arcanist(arcane debuff) acivable/good without Asendent
Wizard help
Wizard help
Effective + Weaken. Whats the weakness
Ignore resist? Newbie
Help please
RIP Arcanist 2016-2016

Thanks for the much needed thread! I mean I didn’t know exactly how much better than Ignore Resist but I knew it was significant!

My Seasonal Maiden with Weaken and Effective extremely powerful along with the insane MH% and even more so with the new Arcanist effect with 200% WD . Can work on any mode.

Ascendant 62.5% reduce all other enemy resists since enemies hardly have arcane resist is on Arcane attacks but I’m almost sure it works on the Debuff (DoT definition) which could help.

Obviously arcane attacks in itself are extremely good as you explained but the Ascendant Debuff by attacks or talents like Wrath or sets like Iceburn I’m pretty sure places the 62.5% reduce resists of all other elements.

Septillion damage ftw!


Effective is only goodish as I’ve learned during my recap writing the guide (will not use it in further builds most likely - Dauntless with Cyclone/Taunt!!). Ascendent will add on damage the same way that weaken does (except Arcane obviously). Although with Arcanist + Ascendent I would probably only use one crystal and one epic Weaken.
The second Weaken would not add as much damage as it would without Ascendent and crystal slots are precious :wink:.

Edit: @ktl09 you will find all info you need in my first post!


Yeah that combo would be very good. Cyclone has its taunt effect kind of like Twisters though but the Taunt Skill has larger AOE. 5% reduction per enemy.


My choice 180% weaken is right :blush:


Superb work as usual @Midlumer

These are some of the not so obvious things people overlook. Great job again and very succinct guide!! +1


Thank you :blush:!

I just empirically determined the average increase for epic monsters. Chance for an epic monster to have Greatly Resist is around 83%.
For it to be of your element is thus 1/5 of that.

  • 90% Weaken increase: 83% * 1/5 * 1.15 + (1 - 83% * 1/5) * 1.9 - 1 = 77.5%
  • 90% -> 180% Weaken increase: 50.7%

Now it’s not perfectly accurate and mathematically a bit dirty, but a value one can work with. Seems to match my previous estimate.

My general solution will most likely be 90% crystal Weaken, 30% epic Weaken, 45% Crit Chance and 225% Crit DMG. That leaves me with three crystal slots for Dodge, Block, RCD or the like.

Thanks mate :blush: can hardly cope with all the praise :ghost:!


If CuzegSpiked = Calculator. This man Midlumer is a Computer :joy::joy::joy: MidComputerLumer.


Lol. Computer > Calculator .


:smile: thank you! But not quite correct I still do mistakes.

As a matter of fact I just edited out some kinks. I think the guide is in a good shape now - please proof read it and let me know if you find errors!

@Clogon @Griffin if you find the time ;).


I still do mistakes too :wink: . It takes many mistakes to learn to become great and a lot of questions. Trial and error.

This game is trial and error in and of itself.


So i dont need effective mythic to go with weaken? Just weaken alone?


Weaken alone is enough actually. Effective+ Weaken also works but totally optional.

I chose it because of the Frozen Explosions in the weakness element. It’s not like that anymore but Explosive 400% still does good damage to help imo.


Yes, you understood that correctly ;).


Thanks for clearing that up… Back to farming then hahah my goal now is to reach floor 10000.



thanks for this. really helpful. i just upgraded my set with 90% weaken and 60% epic weaken and i’m almost 1 hitting shrine champions on floor 1900+ really helpful. thanks again.


i got arcanist + ascendent, crystal crit chance (total 75%), 1x cristal crit gmg, 2x crystal weaken.
another 2 crystal affixes are dodge, and APS (total 75%) so there is no room currently.
my skill is ricochet, 4x extra attack, 4x multi attack
is it worth it to go from 180 weaken to 120 weaken and add another crystal crit dmg?
I suggest yes?


Thanks :slight_smile: you’re welcome.

Why don’t you get 5x Strength Nature and 1x epic Crit DMG%?

Crit DMG% cap is 350%, so you only need additional 125% - a second crystal slot would give you 125% more than you need.

In case you have Epiphany (5) you could do that though. You’d need to calculate that according to the CRITav formula in my other guide:

I’m to lazy for that right now ;). But I’m pretty sure in terms of DPS the second Weaken is better than a second Crit DMG% even with Epiphany.


Hey Mid, thanks for the answer. Yes I got also Epiphany Apex (with set affix and bonus affix) so the cap is 437.5.
Maybe you were so kind to calculate it for me in the next days?
Your guide is very cool but I have some problems to understand everything there :frowning:


hey mid thanks for the response i really appreciate all the hardwork you have put onto this guide. i just found out that my set is more effective with the crushing flames bonus based on my calculations. i will post it soon when i finish farming for my set.