The mechanics of spell hit with counterspell

Errelno · 04/20/07, 4:25 PM

I've read a bunch of people's opinions on this, but wonder if anyone has done any testing on this. What I'm curious about is whether talents like arcane focus (2% less chance to have arcane spells resisted) and/or spell hit above the cap will work against talents like imp concentration aura.

For example, if I have 10% base spell hit, 5/5 arcane focus, and try to counterspell a paladin wearing talisman of the breaker and using imp concentration aura, what is the resist rate?

It seems as though most players don't really know for sure, so a lot of mages think 5/5 AF is a must, where others see it as a complete waste. Has anyone actually figured this out for sure?

chase · 04/20/07, 5:02 PM

Short answer, nobody knows for sure.

Counterspell is a binary spell.

On binary spells hit/miss/resistance are all rolled into the first roll.
Looks something like:
spell hit * resist % = X
Server Roll < X = Hit
Server Roll >= X = Resist/Miss

Now it is never mentioned in the blue post if the hit cap is taken into account in the first roll on binary spells.
If you can exceed the 99% hit cap in the first roll than exceeding the hit cap increases your chance to land the spell.
If you are capped at the 99% hit cap in the first roll than any +to hit beyond (3% for pvp) is worthless and only spell pen (and talents to the same affect) will help you break resistances.

There have been several people who have claimed that exceeding the +hit cap for binary spells (notably frost) does indeed decrease the resist rate. (noted for bosses, and binary spells breaking the boss resist) However, every time I have looked into the claim the data behind it was nothing but smoke.

So you can either belong to three camps:
1) Spell hit beyond the cap increases your chance to land binary spells. So arcane focus is great for landing arcane binary spells. (sheep, CS)
2) Spell hit beyond the cap does nothing for your chance to land binary spells. If you want to break (non-boss) resistance your only hope is spell pen and lots of it.
3) Little faires determine hit/miss/resistance or we just don't know enough yet.

I'm in camp 2 and 3. The only reason I grab arcane focus is because it is the best of the worst talents to grab on the way to clearcasting.

Errelno · 04/20/07, 5:53 PM

I'm mostly talking about in a PvP environment, with respect to talents that increase the chance to resist interrupt/silence effects.

Eylirria · 04/20/07, 6:10 PM

I don't think anyone has ever done any sort of testing about if exceeding the base +hit cap versus a target that actually has more resistance than the assumed cap works.

We know that binary spells are on a single roll that is the result of other information rolled (no pun intended) into one.

We know that it is "Spell Hit * Resist = the_roll"

We know the values we need to cap spell hit, and we know it caps. The question here is whether Improved Conc Aura, or the neckpiece, if their buffs push the spell hit down, or if they push the resistance factor up.

Judging by http://www.thottbot.com/s20256, 3/3 Improved Concentration Aura seems to be pushing something up, and it's not clear what is getting added +15. It would seem that you would either need spell penetration, or something that is just not itemized to counter this particular effect.

From looking at what I could find, it doesn't seem like pushing over the cap would produce any effect for this particular situation, but this is just purely guessing talk out of theorycrafting.

edit: I just looked over Talisman of the Breaker, and other talents that produce similar effects, and the paladin aura effect is just unique. The Talisman and other talents like Focused Mind seem to increase a "Mechanic Resistance", which in theory should be able to be countered by spell penetration. The paladin aura doesnt seem like it falls under any sort of resistance.

chase · 04/20/07, 6:59 PM

Testing this sounds awful. 400 counter spells would be around 3.5 hours.

To test spell pen you could go to a FFA area like stv arena and have a warlock cast CoA and stack spell pen and go to town with CS.
Do the same with no CoS and spell pen and compare.

(ensure spell hit remains static)

Xunwael · 04/20/07, 7:20 PM

Fairly certain that spellhit has no noticable effect on lowering the resistance to silence or counterspell effects by talents, items, auras or other sources.

My mage, with +16% hit to arcane, still has his counterspells resisted atleast 15% of the time against priests, and my shadow priest, with an equal amount of hit to shadow, gets her silence resisted just as often.

Though, I've done no actual testing - just a few years of experience playing the game too much than can really be healthy.

Ghando · 04/20/07, 7:29 PM

My impression was that talent-based (or item-based in the case of the Heroic BF neck) resistance to interrupts is like dodge/parry ratings. It's an active roll on the part of the player being targetted, and as such can't be affected by +hit or spell penetration.

PapaShlapa · 05/01/07, 11:35 PM

Just a bit of brief testing I did.
Had 16% hit with arcane at the time of testing.
Paladin with Imp Conc, no talisman, no arcane resist.
40 CSes - 36 interrupts, 4 resists.
Same paladin with Imp Conc, talisman, 45 arcane resist
40 CSes - 22 interrupts, 18 resists.

If spell hit had any effect on Silence/Interrupt resist, the chance of him seeing 3 resists in 40 CSes would be very low. Not a perfect test, but some evidence at least.

Zoner · 05/03/07, 5:27 PM

Originally Posted by Ghando

My impression was that talent-based (or item-based in the case of the Heroic BF neck) resistance to interrupts is like dodge/parry ratings. It's an active roll on the part of the player being targetted, and as such can't be affected by +hit or spell penetration.

Magic works nothing like the melee system, except for the fact there is a random number involved 'the roll'.

Snow · 05/03/07, 5:33 PM

I did some incomplete testing awhile back, but the sample size was too small to state anything definitive. I'll see if I can find my exact numbers, I have a tally sheet somewhere. The interesting thing was, it was fairly common(well over 15%) to resist the silence with imp. conc aura, but still be interrupted and locked down. On the other hand, I was never silenced and not interrupted, thus, the silence is the "secondary" effect and can only be applied if the first succeeds. I know that's not exactly what you are asking for...