Question about X% chance of Y happening mechanic

There are few instances of this in game.

First one, x% chance of y% cooldown. Like on a set bonus for Clayrvoiant or on green items with Gildam Arcanuum suffix or Ulzuin’s Chosen. How does this work? Is it proced every time we hit a target? (like with every dot tick too?) Does it have internal cooldown?

Then there is x% chance of y energy leech/leech retaliation like on some items/devotion nodes or on Phantasmal Armor skill from Nightblade mastery. Again, does it have an internal cooldown? Does it proc every time we hit a target including dot ticks? How does it scale with weapon damage? In case of energy leech retaliation, does it work every time we get hit?

And also, x% chance of +y% to damage. Same questions basically.

It depends. CDR triggers on skill use, damage/leech etc on target. For example, I have 10% chance for 120 HP leech over 3 secs, 75% for 15k burn over 2 and 1% chance for 100% cool down reduction and I use Blitz:

Pressing Blitz button activates CDR chance, hitting an enemy triggers both leech and burn.

Retaliation works the same, but it’s on-getting-hit.

It’s best to think about these stats as being always active but not always applied.

That is to say that any time you use a skill or do anything that could involve the effect of the proc, the proc chance is rolled to see if it actually procs. So any time you use something with a CD, % Chance of CDR procs are rolled. Any time you use something with Weapon Damage, % Chance of Weapon Damage effects (like leech) are rolled.

Thanks for the explanation, guys.

Is there an internal cooldown for let’s say Clayrvoiant set bonus?

Also, does energy leech scale with weapon damage? (like with 30% weapon damage i only get 1/3rd of my total energy leech)

Not quite.

No, just as there is no internal cooldown for the damage bonus from Decorated Soldier, for example.

However, there is still a limit imposed by attack and cast speed so that the exact same skill cannot proc that set bonus twice at exactly the same instant.

Finally there is the limit imposed by how quickly the game updates its state, which can be CPU-bound.

The tricky question - and one I’ve never been able to figure out coz I’m dumb - is how these different sources stack.

Say I have 10/10 ulzuin’s chosen + Gilman arcanum suffix. What then?

This has been researched ages ago by someone else. They stack multiplicatively.

Here’s the real tricky part - increasing CDR provides increasing marginal returns but multiplicative stacking of multiple chance-based CDR sources provides decreasing marginal returns. So what will be the net effect? This is a maths problem that I CBA to solve right now. :cool:

EDIT:

If you’re talking about how TD stacks with Ulzuin’s Chosen for example, well you could call it “destructive interference.” Suppose you bound TD to Canister Bomb. If you cast it and UC procs, then you have an extremely short window of opportunity to exploit it before TD procs from the first CB explosion. So it’s actually better to bind TD to a non-UC skill like CT, for example, so you can optimise exactly when TD procs.

That last part about not binding TD to skill like Canister Bomb, thanks, I will use it in my sorc build.

also, if I attack multiple mobs with aoe skill like for example grasping vines, and I have 40% weapon damage on this skill from Wildblood set and 15% chance of 50 energy leech. Will it proc 15% chance of 20 energy leech (because decreased weapon damage) against each mob it hits every time it hits it?

This doesn’t sound correct. Do you have personal confirmation or are you reposting DaShiv’s testing?

Edit: Just tested Mastery Passive Skills (Fighting Spirit). Definitely affected by % Chance of % CDR.

Edit 2: Item Actives and Passives are unaffected by % CDR, whether it be a proc chance or not.

As far as the middle column goes, it’s a repost. What’s wrong with it?

Exactly right. Energy leech is just another type of flat damage.