Question on Mezz Resist IOs

Hello Folks,

I have been looking at IOs alot lately and a question arose that I didnt know the answer to.
Perhaps someone could help me out with this.

IO set resistance to Mezz effects can stack (Which I knew), but how does that actually effect the duration of an effect.
For example Health has a passive 48% sleep resist, and with IOs, I can easily get this to 90%.

Does this make the duration of a sleep effect 10% of its normal length, or.. 100%/190%
approx: 52% of its normal duration ?


Thanks for any help

It's the latter - 100% mez reist cuts the duration in half. So, in your example, 90% sleep resist does indeed cut the effect to 1/1.9 of its original length, or about 52%. Which makes mez resistance from IOs somewhat underpowered in my opinion - the percentages are usually very small.

For reference, Accelerate Metabolism offers +216.25% mez resistance.

You're right - the piddly little single digits from set bonuses aren't noticeable at all.

Although the Aegis unique provides 25% mez resistance or a 1/(1 + .25) = 80% so a 20% reduction in duration. Which for me, at least, is worthwhile. Also the Impervious skin IO is 1/(1+.075) which is 7% reduction, which might we worthwhile depending on your build. Unfortunately mez resistance is susceptible to diminishing returns (due to the inverse nature of the relationship, something that the true numbers doesn't accurately report). So the two together are only 1/(1+.325) => 24.5% reduction. But the set bonus numbers are hardly worth mentioning.

The aegis unique is the only IO mez resistance bonus worth getting, and only for certain specialized builds.

I seem to recall reading about that stacking effect on the Aegis IO.

But for the rest of it Draggynn, I guess that just leads me to more questions.

Let me use an example; I take 5 powers and slot the 7.5% resist IO from ImpSkin in each one, and then in a Toggle I put the Aegis IO. On paper these would seem to say you have 57.5% resist to mezz. Then 100%/157.5% means 63.5% mezz duration.

With them being non-intuitive, do you mean this would actually be;

100% / (1.25 x 1.081 x 1.081 x 1.081 x 1.081 x 1.081) = 1/1.845

and the end result being 54.2% duration of mezz effects ?

P.S. : I hope my math is right here

You're close to right. The problem is distinguishing between mez duration reduction and mez resistance. The Aegis provides 25% resistance, and each impervious skin provides 7.5% resistance (The text claims 7.5 duration reduction, but this is wrong it's resistance, while the aegis claims 20% duration reduction and this is correct, since it's really 25% resistance). Thus your total mez resistance is actually (7.5*5 +25) = 62.5% which results in a mez duration of 1/(1+.625) = 61.5% or a mez duration reduction of 38.5%.

The actual calculation is straightforward, except that real numbers reports mez duration reductions. If you look at the real numbers, it will report your imperious skin bonuses as providing a 1 - 1/(1+.075*5) = 27% reduction and your Aegis as providing a 1 - 1/(1+.25) = 20% reduction but your total mez duration reduction is really only 38.5% not the 47% that they would suggest. The mez duration number reported in true numbers is accurate, but the percentage reduction numbers aren't.

Hopefully that helped. Let me know if you have further questions.

Thanks Draggynn

That does help alot. I would need to look very closely at the descriptions on set bonuses and powers like Health then to determine which number to use.
Figure and Tally all the actual resistance values before doing the reciprocal.

So, Best case scenario for a defender, using Health, Sonic Resonance powers all slotted with ImpSkin, and a couple 5-piece Basilisk gaze bonuses would MAYBE push the duration of sleep to just under 40%.

In Contrast, ANY defender could take ONE resist power, Health, 1 ImpSkin and 1 Aegis IO and get to around 55%. Too bad really, would have been nice to see Sonic have a niche as the king of Status resist for Squishies. Looks like FF can rest easy