Lhivera’s Library

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Arcane and Invocation: Really a Good Match?

Friday, March 30 2012 at 1:28pm CDT

Many have been assuming since the announcement of Invocation that the optimal Arcane playstyle will be to spam Arcane Blast until at sufficiently low mana to evocate reasonably, recharge, and repeat. I don't think the numbers make this nearly so clear as seems to be the popular opinion on the official forums.

This post is not meant to be an in-depth analysis with answers about the best MoP Arcane rotation; it's simply a look at some of the numbers involved intended to challenge these assumptions and start a discussion. Most of the information below was posted on the forums, but is collected here in a more readable form.

The Talent Buffs

Rune of Power is simple: a 1.15 multiplier, and an increase in regen/sec from 1% to 2%. Of course, it gets a lot less simple if you have to move, but that's something we can explore in discussion.

Invocation is trickier. The total benefit depends on how often you use it. Optimal is once every 46 seconds — 6 seconds of evocating followed by 40 seconds of casting. Deviating from this in either direction reduces the benefit.

The average multiplier is: 1.3 * time between evocations / (time between evocations + 6). Some examples:

  • 40 seconds: 1.3 * 40 / 46 = 1.1304
  • 30 seconds: 1.3 * 30 / 36 = 1.0833
  • 20 seconds: 1.3 * 20 / 26 = 1.0

Mana Consumption

With zero haste, net mana consumption per cast with Invocation including the 1% regen over the 2 second cast time) is:

  • 0 stacks: 0.5%
  • 1 stack: 2.375%
  • 2 stacks: 4.25%
  • 3 stacks: 6.125%
  • 4 stacks: 8%

With rune of power:

  • 0 stacks: 0%
  • 1 stack: 0%
  • 2 stacks: 1.25%
  • 3 stacks: 3.125%
  • 4 stacks: 5%

And there's the rub for the Invocation Spam concept

At four stacks, you're losing 8% mana with every cast. You'll need to evocate every 16-25 seconds (presumably spending some time on Arcane Missiles), effectively negating your Invocation damage buff. A four-stack spell only does about 14% more damage than a three-stack spell (200 / 175 = 14.29); factor in the lower average Mana Adept bonus, and it doesn't look to me like you come out ahead.

Here are some examples if you want to play around with the numbers. Since you're comparing multipliers, you don't really need to worry about base damage. You can just compare the multipliers. Higher multiplier means higher damage. 

Mastery Multiplier * Mana Level * Arcane Charge Multiplier * Buff Multiplier


  • Base mastery, 92% mana  four charges, 20 sec evo: 1.12 * 0.92 * 2.0 * 1.0 = 2.0608
  • Base mastery, 76% mana, four charges, 20 sec evo: 1.12 * 0.76 * 2.0 * 1.0 = 1.7024
  • Base mastery, 93.875% mana, three charges, rune: 1.12 * 0.93875 * 1.75 * 1.15 = 2.1159
Share your thoughts!


Submitted by Fennor on

Does evocation still provide the first 15% mana instantly? If so, we could use evocation every 12 seconds for only two seconds (two ticks). Every third evocation has to be channeld for the full duration in order to get the damage buff. Then we have a new multiplier: 1.3 * 36 / 46 = 1.0173913

That makes it possible to have slightly higher mana regeneration as we'd have when evocating every 20 seconds, but still have a better damage mutltiplier.

Submitted by Fennor on

Also, I think runes of power are on the GCD, so it has a multiplier of 1.15*58.5/60=1.12125

Submitted by Lhivera on

...or, assuming perfection, 1.15 * 60 /  61.5 = 1.122, as you can start the recast after it expires. A bigger issue is going to be moving around and potentially having to maintain two of them. (They actually have a cast time of 1.5 sec, so the timer doesn't start until the end of the GCD.)

Submitted by Fennor on

Hm... are you sure about the 60 / 61.5? I think that would be the case if runes of power had a 1.5 sec cast time. That's why it is 40/46 for evocation instead of 34/40. I think it would be 34/40 if evocation triggered a 6 seconds GCD instead of having a 6 sec cast time.

But never mind, I guess it doesn't really make the difference.

Submitted by Lhivera on

The runes do have a 1.5 sec cast time...of course, that means you can't place them while moving without use of POM or Ice Floes.

Submitted by Aowyn on

1.15 * (60/61.5) = 1.122, lower than the 1.13 found for Invocation. I wish I had seen it before =\

Submitted by Malon on

Just pointing out you've factored in 1% base mana regen during casting while specced for Invocation - currently, it reduces that to 0%.

Submitted by Lhivera on

...and I don't think they have, it now reduces regeneration by 50%, rather than 100%. I've factored it in as 1% per 2 seconds accordingly. You're probably thinking of the version on the online talent calculator, which is out of date.

Submitted by Aowyn on

Just in case your talent calculator is outdated, you can find updated information in http://mop.wowhead.com/mists-of-pandaria-talent-calculator#m!

Incanter's Ward has potential for better average increase in damage than both Invocation and Rune of Power in this case, since it can maintain +30% damage for 15s every 25s. Assuming the mage use it during movement due to its instant nature and that the boss deals enough damage to deplete the absorption, we have (1.3*15 + 1*10)/25 = 1.18 average increase in damage.

On the other hand, the mana return promises to be lower, 15% every 25s nets an average of 0.6% of maximum mana per second in an ideal situation. This doesn't affect fire or frost much, though, only arcane, and means restriction of when using a burn rotation to get optimal damage, which isn't always feasible. It would be weak on Hagara, for instance, since you would have to take lots of damage just before she is stunned, and doing that when she summons frost is likely to kill you, even with Cauterize.

Where Invocation shines is with Arcane Power factored, since the power increase is just as easy to obtain as Rune and has doubled damage multiplier with this one:

> Invocation (1.3) + Arcane Power (1.2) = 1.56 damage multiplier during 15s, excellent for burst. Assuming evocation after AP expires followed by two evocations (haste factored as ~9.10% to reduce channeling time to 5.5s), we may obtain (1.56*15s + 0*16,5s + 1.3*59,5s)/90s = 1.19444... , roughly 1.194, in every cycle of 1.5 min, the cooldown of Arcane Power.

> Rune (1.15) + Arcane Power (1.2) = 1.38 damage multiplier during 15s, weaker burst. Assuming Rune of Power is renewed every 1 min (for an average of 2,06s spent casting it with 9.10% haste), we have (1.38*15s + 0*2.06s + 1.15*72.94s)/90s = 1.16201111... , roughly 1.162, in every cycle of 1.5 min. It doesn't account for better consistency of Mana Adept damage increase, though.

> Incanter's Ward (1.3) + Arcane Power = 1.56, just like Invocation. Assuming it is refreshed every 25s, 9.1% haste, that the first is used with perfect timing with AP, 1.375s*4*90s/100s as an normalization term for how often we are in global recasting Incanter and an average of (1.3*15s + 1.0*8.625s)/23.625 = 1.1905, we get (1.56*15 + 1*10 + 0*4.95s + 1.1905*60,05)/90 = 1.16544, roughly 1.165 in every cycle of 1.5 min. This is an ideal case, however, when the mage can perfectly time the Ward depletion with Arcane Power's cooldown, and doesn't factor the lower mana return for Mana Adept nor usage of Evocation, both likely to lower the average.

Invocation seems the most powerful talent for Arcane here, both in average damage and praticity. Fire And Frost, however, may see better results with Rune of Incanter due to the 1.1306 average for Invocation found by Lhivera. Take into account however that the above calculation doesn't assume that the arcane mage will be spamming burn rotation followed by Evocation every time, but that it will follow a burn and conserve rotation.

Note: the 9.1% haste was chosen because I wrongly assumed that arcane would try to use two evocations only during a 1.5 min cycle, but the Mana Adept would likely have an impact on the damage after using AP. I'm yet to redo these calculations with no haste factored.

Submitted by Aowyn on

In the last but one paraghaph, I meant Rune OR Incanter. Rune of Incanter would be too powerful of a spell =P

Since these calculations didn't take Mana Adept into account, we may see lower average for Invocation too. It should be worth to see how much damage the burn rotation does in comparison with the conserve one, especially since AM and ABarr benefits from Arcane Charges now.

Submitted by Aowyn on

We need to explore the ratio of burn and conserve rotation to see whether Mana Adept and the frequent evocations (every 16-25s) reduce Invocation's value too much.

Assuming, for simplicity sake, that a AB does an average of 100 damage and that ABarr deals 75 and that casting bombs change little for average dps in regard of talent chosen, we have for a conserve rotation that 4 AB + ABarr with Rune of Power does (100+125+150+175+150)*1.15 = 805 damage in 9.5s => 84.74 dps with no haste. It's Burn rotation should deal 200*1.15 /2 = 115 dps.

With Invocation, assuming AB spam and that Arcane Charges' duration of 10s allows AB to have 4 charges after evocation, we have 200*1.3/2 = 130 dps. With no haste factored and considering between 16-25s of burning followed by evocation, we have:

worst case: (16s*130dps + 6s*0dps)/22s = 94 dps, 10.93% more damage than the conserve phase with Rune of Power

best case: (25s*130dps + 6s*0dps)/31s = 104 dps, 22.73% more damage than the conserve phase with Rune of Power

To find the ratio of how long the burn phase with Rune of Power has to be compared to the conserve rotation to obtain competitive results with Invocation in both cases, we have (a*115 + (1-a)*84.74) => (84.74 + 30.26*a), where a = [0, 1]. We have, then:

To match the worst case: a = 0.306

To match the best case: a = 0.636

In both cases, the arcane mage with Rune of power would have to spend considerable time burning her mana, which may end invalidating the damage increase with Mana Adept, especially since Rune replaces Evocation. It becomes more concerning once we factor the multiplier added by Arcane Power, which interacts better with Invocation, as shown in the comment before.

Unless Rune is buffed or a Mastery-focused build gets considerable improvement in Rune's conserve phase over a haste-build for Invocation's, Rune may end never being a PvE competitive talent.

Submitted by power on

you ignore arcame missiles:

Invocation: every proc nets you: am-damage (4stack) + 1% mana

Rune: every proc nets you: am-damage (4stack) + 4% mana

Submitted by Hercules on

that invocation was the superior spell... the fact that it has NO cast time makes it superior when that 1.5 second makes a difference... well, the hardcore raiders will have their mages specc'd into invo.

Submitted by Hercules on

then rune will be superior... but i'm willing to bet that there will be a lot of movement

Submitted by Lhivera on

Not sure what you mean. You have to complete the full 6-second (minus haste) channel of evocation to activate Invocation's buff.

Submitted by Ridesdel on

Since w/ Invocation removes the CD on evo, couldnt in the last 15 seconds of invoc you have a mini burn phase and dump your mana to ~50% before the full evo?