Definitive Critical Strike Chance Formulae

General
1

Just making this so if I need to find the formulae i can get to it through my profile/bookmark, obviously also use this if you need to! (Ignore the examples if they aren’t needed, they are only there for if the formulae are unclear).

Though the Character Sheet displays your crit chance of all types, it only factors in global and generic increases, not factoring in skill trees and things like “crit chance for lightning skills”.

Minion critical strike chance is calculated in the exact same way as players, so this formula works to calculate a minions crit chance as well. (minions also have 5% base crit chance).

Calculating Critical Strike Chance:

Formula:

x * (1 + y%) = Critical Strike Chance

Key:

x = Base crit chance + Added % crit chance from all sources.
y = Increased % crit chance from all sources.

Example:

If you had 5% added crit chance from your base crit chance, and +10% added crit chance from source 1, x would be 5 (base crit chance) + 10 (source 1). Meaning x = 15

If you had 100% increased crit chance from source 1, and 50% increased crit chance from source 2, y would be 100% (source 1) + 50% (source 2). Meaning y = 150%.

calculation with 15% total added crit chance and 150% total increased crit chance:

15 * (1 + 150%) = 37.5% Critical Strike Chance

Calculating with multiplicative increases:

Formula:

x * (1 + y%) * (1 + m1%) * (1 + m2%) = Critical Strike Chance

Key:

x = Base crit chance + Added % crit chance from all sources.
y = Increased % crit chance from all sources.
m = More % crit chance from a single source. (Number differentiates sources).

You can have more than 2 sources of “more”, you would just consider those m1, m2, m3… etc and they follow the same rules as the 2 sources used.

Example:

If you had 5% added crit chance from your base crit chance, and +10% added crit chance from source 1, x would be 5 (base crit chance) + 10 (source 1). Meaning x = 15.

If you had 100% increased crit chance from source 1, and 50% increased crit chance from source 2, y would be 100% (source 1) + 50% (source 2). Meaning y = 150%.

If you had 20% more crit chance from source 1, and 30% more crit chance from source 2, meaning m1 = 20%, and m2 = 30%.

Calculation with 15% total added crit chance, 150% total increased crit chance, 20% more crit chance and 30% more crit chance:

15 * (1 + 150%) * (1 + 20%) * (1 + 30%) = 58.5% Critical Strike Chance

If I have gotten any calculations wrong or could simplify any of them please let me know and I will edit this post ASAP. Hope this helps and have a good day! <3

EDIT: Reformatted the formulae and fixed the “more” formula which I believe was incorrect. Big thanks to PvtVlad.

EDIT: For an explanation on calculating when factoring in Critical Strike Avoidance and Critical Vulnerability on an enemy, please read the comments below, as people much smarter than me have explained how it works alongside the formulae. Many thanks to those commenting!

2

Hum… You are making it harder on yourself, and when I read you it seems wrong but we arrive at the same results.
It’s simpler if you do

(Base Crit + Added Crit) x ( 1 + Inc Crit Chance%) x ( 1 + More Crit Chance %A) x ( 1 + More Crit Chance %B) x…

Added Crit is the sum of all the added Crit Chance from all sources
Inc Crit Chance % is the sum of all increase Crit Chance from all Sources.

2 Likes
4

hm it seems the “more” calculations are giving different results, i think ive gotten the formula incorrect, I will reformat to match the ones you have sent since you probably have a greater understanding of all this. Ty for the help!!

5

The maths is the same as the damage formula, though simpler on account of there being different damage elements (phys, fire, void, etc) & types (melee, spell, etc) & the formula for that is in-game as well as on the forum in various places.

6

oh good to know! I knew the calculations would be practically the same, just didnt realise there were easy ways of finding it.

7

There is also Critical Vulnerability ailment, that adds a flat crit chance on top of your total crit chance

8

Very true, though I doubt you need to use a formula for that, since its just adding onto whatever your total crit chance is.

If you have +20% crit chance from crit vulnerability, and it is applied before calculating, you just add it to x. If its added on after, you just add 20% to whatever you get from the formula.

9

It’s not, sadly, though it was originally.

10

Whichever way it works, it should be very easy to factor in, can you give me a proper explanation of exactly how critical vulnerability interacts with the formula and I can edit it into the post.

Hope thats not too much trouble and I would greatly appreciate it! <3

11

Critical Vulnerability adds flat crit chance per stack but this flat crit chance isn’t affected by anything else. So at max stacks it reduces the “normal” crit chance you need to 80% if you want to hit crit cap.

12

Should be enough, but… only with zero crit avoidance :roll_eyes:
Crit % + CV% - CA% = resulting C% chance
where Crit % is that formula of base, added, inc and more crits from one of the previous answers

Last layer is - crit multiplayer, as it can affect crit so hard that it will be = normal dmg strike (but still proc some On crit effects)

13

Which Crit Vulnerability also reduces…

Crit Avoidance is multiplicative, not additive.

14

Hmm
(Crit % + CV%) * (100% - CA%) with no negative ?

1 Like
15

Yup, crit avoidance is just a multiplier at the end, after crit vulnerability

1 Like
16

Crit Vulnerability also reduce Crit Avoidance

17

Are you saying that Crit Vulnerability allows you to crit on a target with 100% crit avoidance?

Because I have never seen that occur.

18

https://www.lastepochtools.com/ailments/critical_vulnerability

-10% Critical Strike Avoidance per stack up to 10 stacks

1 Like
19

Ah, you meant like that. I thought you meant that the extra crit would ignore crit avoidance (so at 10 stacks an enemy would still be crit even with >200% CA)
Sorry if I worded it badly.

So the complete formula would then be:

( Attacker_Crit% + CV_Crit% ) * ( 100% - (Defender_CA% - CV_CA%) ) = final chance to crit

1 Like
20

What a twist.
So for 0% CA target with max CV stacks (10/10)
30% Attackers Crit chance is an effective cap as it will be a guaranteed crit
(30%+102%)(100%-(0%-10*10%) or 50×2=100

21

You would have to test it, but I’m assuming negative Crit Avoidance doesn’t work.
So at 80% Attacker Crit, you’ll guarantee crits with 10/10 Crit Vulnerability, unless the target has >100% crit avoidance.

Again, Edge cases need testing to confirm, but I recall the crit vuln change (from 5% to 2%+10% CA) was just to counter mono mods, not to just double your crit.