Spellpower coefficient The best place to start when designing a DPS spell rotation is with the spells themselves. And while there are many qualities that define just how much damage a specific spell can do (like critical strike and haste percentages, for example), none is more important than what is known as the spellpower coefficient. The spellpower coefficient is a number that dictates the combination of a spell's base damage with a specific amount of the bonus spellpower you carry with you on your gear. In other words, the coefficient decides how much of your increasing spellpower gets applied to any given spell's overall damage production. For example, Shadowburn has a spellpower coefficient of 0.50 or 50 percent. What this actually means is that 50 percent or half of a warlock's bonus spellpower will be added to his Shadowburn's base damage. For a warlock with 3,000 bonus spellpower, that's 1,500 in damage added to Shadowburn's base damage value.
The spellpower coefficient is really not that difficult a value or concept to understand, and it's easy to calculate, too. But finding the correct values to use in its calculation can prove to be quite the task. Thankfully, there is a fairly easy way of ensuring accurate values, and like most great things, it involves getting naked.
To find the spellpower coefficient of any ability in the PTR or beta, simply do the following:
In your interface options menu under the Help section, make sure that Beginner Tooltips is unchecked. This will display actual damage values in your tooltips rather than generalized and simplistic descriptions of what each spell does. Also, make certain that your character has not selected a specialization -- doing so will alter the values in those tooltips, adding tree and mastery bonuses to them and complicating your calculations. In fact, you should have no specialization or talents selected or buffs of any kind. If you do, right-click them away to nothingness before moving on to the next step.
Now that you're spec-less and talent-less, it's time to get your gear on -- or off, I should say. But before you get too excited and make a mess of things, you may want to create a save in your Equipment Manager (found in the top right corner of your Character Info window) when fully geared, and then another once you've stripped down to your skin suit, just to make it easy to switch back and forth between the two. I named my saves after two ex-girlfriends. Feel free to name yours however you wish.
Once your character is in the buff, open up your spellbook and find an ability for which you want to calculate the spellpower coefficient. Check the tooltip of that ability and note the damage value (which has been simplified greatly -- no more finding averages!). Now, put all of your gear back on and check the tooltip again, also noting the increased damage value. To find the coefficient, simply subtract the "no gear" damage value from the "full gear" damage value and divide the difference by your gear's total bonus spellpower:
Spellpower Coefficient = ("Full Gear" Damage - "No Gear" Damage) / Bonus Spellpower
An important note: Your bonus spellpower is not
the amount of spellpower your Character Info window says you have when fully geared. It is actually that amount, minus the spellpower value of your character when all of your gear has been removed -- again, you have to get naked to help display the correct values.
Being able to find the correct spellpower coefficients is an important first step in creating a DPS rotation. Since it can be a tedious job that may require a good chunk of time, I've gone ahead and posted them down below for you to enjoy. That said, because we are still in the beta phase of the expansion, these numbers can and have already changed, so getting used to calculating them yourself is definitely something to consider.
The next step in creating a spell rotation is to calculate the average amount of damage each spell in your arsenal can produce. Calculating the average damage per cast time (aDPCT) does just that and quantifies each spell with a value that gives the ability a specific place in a priority rotation. The greater the aDPCT value, the higher up in the rotation's priority a spell will be. For example, if Spell A has an aDPCT of 10,000 and Spell B has an aDPCT of 12,000, Spell B will be case before
Spell A, since it has a higher aDPCT.
The aDPCT value, when calculated properly and thoroughly, is the most important step in conjuring a DPS rotation. But do not underestimate the amount of information you'll need for every one of your spells -- you not only must consider a spell's coefficient and base damage, but also its specific critical strike percentage, haste rating, mastery and tree bonus, glyphs, talents, spell procs, etc. Needless to say, the process is very detail-oriented, and the more accurate you are with the details, the more precise you'll be with your calculations.
Once you have as much relevant information as possible gathered on a particular spell, plug those values and information from your specific character (bonus spellpower, critical strike and haste percentages, mastery bonus, etc.) into the following equation to calculate the aDPCT (make certain that all of your percentages are in decimal form):
aDPCT = (base dmg + (bonus spell dmg*Coeff))*(1 + Crit)*(1 + mastery)*(1 + tree bonus) / (base cast time / (1 + haste))
If it seems a little overwhelming, don't worry. I've done all of the calculations for you and posted them below, along with the coefficient values (of most spells, except channeled and AoE spells). It would be helpful to familiarize yourself with this process, however, so if you're in the PTR or beta, I'd suggest grabbing some info and experimenting with the aDPCT equation and comparing them to the values below. And hey, if you find a mistake, I will personally get naked in your honor -- all for science and theorycrafting, of course.
Also, as a side note, it is important to mention that the aDPCT values below are based on a level 80 warlock, meaning that stat values are much higher than they will likely be once we reach level 85.
for full duration
Based on a level 80 destruction warlock (2/3/31) -- 4.0.1 PTR
Critical strike rating
8.00 (10% increase to fire damage)
Bane of Agony
- 8,586.62 w/ Doom and Gloom (Increase critical chance by 8%)
- 10,733.28 w/ Doom and Gloom, 3 extra ticks from haste (1 tick added to each group)
Bane of Doom
- 32,819.64 w/ Doom and Gloom (Increase critical chance by 8%)
- 7,737.67 w/ Improved Corruption
- 10,316.90 w/ Improved Corruption (.12 increase), 2 extra ticks from haste
- 2,126.96 + 7,723.96 = 9,850.92
- 3,509.48 w/mastery, tree, talent + 14018.99 w/mastery, tree, talent (.20), glyph (.10 increase)
- 17,528.48 w/mastery, tree bonus, glyph, talents
- 20,332.27 w/mastery, tree bonus, glyph, talents, 1 extra tick from haste
- 2,728.39 (assumes Emberstorm)
- 3,410.04 w/ Immolate on target
- 5,844.88 w/ Immolate on target, mastery (.25), tree bonus (.10), glyph (.05), talent (.12, .06 increases)
- 8,349.63 w/ all buffs and backdraft proc
- 6,138.91 w/mastery, tree
- 9,077.95 w/mastery, tree bonus, Improved Searing Pain (^crit 40% when target below 50%)
- 2,929.63 (assumes Bane)
- 3,281.19 w/talents (.12 increase)
- 4,687.41 talent and Backdraft proc
- 4,714.44 w/mastery, tree bonus
- 9,428.88 w/mastery, tree bonus, instant cast
- 4,114.49 (assumes Bane)
- 5,996.88 w/mastery, tree bonus, talent (.06 increase)
- 8,567.29 w/mastery, tree bonus, talent Backdraft proc
- 14,018.99 w/mastery, tree bonus, talent, glyph (for Immolate)
- 2,686.98 w/mastery, tree bonus
Next week, we'll take a close look at the application of these values, designing rotations for each of our incoming talent trees and their respective specializations. In the meantime, experiment with the numbers above, and see what you can come up with. Enjoy.
Blood Pact is a weekly column detailing DoTs, demons and all the dastardly deeds done by warlocks. We'll steer you toward tip-top trinkets and Soulburning your way through Cataclysm.