How are proc chances calculated?

Grim Dawn Gameplay Discussion
1

Hi all. I am trying out a DEE Witch Hunter build and I just got Scorpion Sting from the Scorpion devotion. At first I bound it to DEE and it seemed to proc as the tooltip says (25% chance on attack), but I tried it on Shadow Strike (as the build guide suggests) and now it seems to proc every time.

Why is this? How does this work?

Thanks!

2

Skills on longer cooldown get an increased chance to proc. Precise calculation is unknown though

3

Go back to the devotion screen and look at the cooldown of the devotion proc after you bind it to an ability. It will be updated with the new proc chance. Higher cooldown base ability = higher devotion proc chance.

4

Is it?

procChance = procRate * (1 + (cooldown * 81)/100) * (1 - (attackDuration * 11) / 100)
5

What is attack duration?

6

It’s the time the attack lingers on screen. An example would be transmuted BWC which has 5 seconds cooldown but because it lingers for 5 seconds, it doesn’t increase the proc chance of devotions by much. A skill with 5 seconds cooldown with no lingering time will increase devotion proc chance much more than transmuted BWC.

7

Thanks guys! I’ll check the devotion screen when I get a chance. I didn’t think it might get updated like that. Pretty cool!