I’ve determined some inconsistencies in how cooldown recovery works with nodes inside a skill’s passive tree in combination with sources outside it.
With Volatile Reversal, the different cdr nodes are additive with each other, but sources of cdr outside the tree add up to a factor which is multiplied against this rather than added to it.
For example, if I have Timelost Vitality (+60% cdr) and Traveler’s Fatigue (+50% cdr) , and outside the tree, I have the Sentinel passive Valiant Charge (+30% cdr) and a pair of boots with T6 27% cdr, I would expect all sources to be additive and produce:
24 / (1+0.6+0.5+0.3+0.27) = ~9.34 seconds
But I actually get a 7.3 second cooldown, likely due to the following math:
24 / [ (1+0.6+0.5) * (1+0.3+0.27) ] = ~7.28 seconds
This can also be thought of as 2 steps, in which the skills cooldown is “reset” to a new number from it’s tree nodes:
24 / (1+0.6+0.5) = ~11.43 → ~11.43 / (1+0.3+0.27) = ~7.28 seconds
I confirmed this by starting naked with a 24 second cooldown and taking these nodes (or the 300% from Timelost Wisdom) and outside sources in different combinations.
However, testing other skills, I get mixed results. Some of them will add with sources outside the tree (as in the first equation above) and some will multiply (as in the second/third equation above). So far, I’ve tested:
Volatile Reversal: multiplicative
Void Cleave: additive
Snap Freeze: multiplicative
Volcanic Orb: multiplicative
Teleport: additive (going left, increasing the cooldown to 11 and then reducing again)
I noticed 2 different wordings in the tree nodes, in case those were intended to represent the difference in logic:
“Cooldown Recovery Speed: +X%”
“Increased Cooldown Recovery Speed: X%”
But Teleport uses the former language and Void Cleave uses the latter language, and both of those are additive.
Not sure what is and isn’t a bug or typo here, but consistency would be nice.
Suggestions:
I personally would like cdr on gear to be good, and they’re competing with some strong suffixes (and you can only get it on belt and boots), so I would prefer the Volatile Reversal multiplicative scenario to simply be universal to cdr on all skills, so that the first cdr affix on gear isn’t already giving diminished returns.
On a related note, I think it would be a good idea to have increased area of effect do the same. I haven’t tested this (I don’t know how to without counting pixels), but after trying the increased area affix with some skills to see a dissapointingly small increase each time, I imagine it’s because it’s additive with the area increases from nodes in the skill trees (which often offer about 100% already, halving the effectiveness of the stat on gear).
It would be nice to see the area affix actually compete with others, since it’s a stat that actually results in a change in gameplay, and a really satisfying one at that.
Also, in these cases, the nodes should clearly state “multiplicative with other modifiers” as “more” damage nodes do (If you still want Volatile Reversal nodes to add together first, then they would need some extra explanation).