One of the biggest mysteries for shadow priests during the development of Cataclysm was what our mastery mechanic would be. We had some vague notions of what we were getting early on -- Shadow Orbs -- but it took the boys at Blizzards a very long time to define what those orbs would actually do.
Perhaps it's that history that leads to one of the greatest misconceptions among shadow priests today. Most of us believe that Shadow Orbs are our mastery mechanism. They're not. If they were, shadow priests wouldn't see them until we trained mastery at level 80. Instead, we start seeing orbs as early as level 10.
Leveling with Shadow Orbs
Though the Shadow Orb is technically not the shadow priest mastery ability itself, understanding shadow priest mastery requires you to understand how orbs work. We gain access to Shadow Orbs as part of our shadow specialization at level 10.
Shadow orbs are generated through casting Mind Flay and through ticks of Shadow Word: Pain. At level 10, a tick of either spell has a 10% chance to generate a Shadow Orb. You can begin to increase this chance as early as level 29 (if you choose) through the Harnessed Shadows talent on your talent tree. One talent point brings the chance of proccing a Shadow Orb up to 14% per tick; two talent points brings this chance up to its maximum of 18%. The talent also gives you the ability to generate shadow orbs if an enemy hits you with a critical strike -- a very useful thing while leveling, questing, or otherwise attempting content solo.
Though they appear as a 60-second buff, Shadow Orbs don't do anything on their own. Instead, they're akin to (and forgive me for repeating this analogy) shadow priest currency. You can have up to three stored up at any given time.
Spending a Shadow Orb is as simple as casting Mind Blast (and later, casting Mind Spike). A single casting of the spell will consume any and all Shadow Orbs you've accumulated up to that point. Consuming Shadow Orbs has two effects:
- Consuming a Shadow Orb increases the power of that cast of Mind Blast. At level 10 (and all the way up to level 80), each Shadow Orb has a set value of 10%. In this way, a cast of Mind Blast when you have 1 Shadow Orb available causes the spell to hit for 110% of its usual damage; a cast of Mind Blast when you have the maximum of 3 Shadow Orbs available causes the spell to hit for 130% damage.
- Consuming a Shadow Orb gives you a 15-second buff called Empowered Shadow. At level 10 (again, all the way up to level 80), the buff increases the damage dealt by your damage-over-time spells by 10%. This buff does not and cannot increase in strength by consuming a stack of two or more Shadow Orbs.
Mastery: Level 80 and beyond
As I said before, technically, Shadow Orbs are not shadow priest's mastery bonus. The bonus, which you can get at level 80 by visiting a trainer, is Shadow Orb Power. It dramatically increases the power of each Shadow Orb.
At level 80, each shadow priest is given 8 points of what we'll term "greater mastery." With each point of this greater mastery worth an extra 1.5% of damage, your shadow orbs instantly increase in power to a minimum value of 22%. This affects both sides of consuming a Shadow Orb: You can cast Mind Blast for 166% of its usual damage (by spending 3 orbs) and increase the power of your DoTs by 22% for 15 seconds (regardless of how many orbs you spend).
Once you start entering Cataclysm content, you'll start finding gear with what we'll term "lesser mastery." It takes approximately 179 points worth of "lesser mastery" to add up to one point of "greater mastery." Each point of lesser mastery thus increases the power of your Shadow Orbs by 0.084%. It's worth noting that the game tooltips round these percentages to whole numbers, but in practice, each point of mastery does increase the power of Shadow Orbs.
Chances are, mastery is not going to be your best secondary stat. You shouldn't be actively stacking it through gems and reforging for it. As a rule of thumb, a point of "lesser mastery" is approximately equal to a point of critical strike rating for most shadow priests.
When should I consume Shadow Orbs?
In general, you should consume a Shadow Orb as soon as you have one available. There's no real strategy to it, and no real value to saving them up. (Perhaps that's a flaw in their design?) Mind Blast is a powerful spell, and you should prioritize it over Mind Flay regardless of how many Shadow Orbs are active.
The most powerful aspect of Shadow Orbs isn't really the additional damage to Mind Blast (though seeing those ridiculously large crits is great). The real power of Shadow Orbs is in increasing the power of our damage-over-time spells via Empowered Shadows. You'll want that buff active at all times, if possible.
For the most part, Shadow Orbs will be a forgettable part of your arsenal. You'll generate them and consume them often without thinking. This is okay, and indeed, standard operating procedure. It is a rare occurrence when Empowered Shadows drops off during a boss fight, and even when it does, we're somewhat powerless to do anything about it. We're at the mercy of a random number generator.
Gaming your Mastery through trinkets
Consider what I said in that last paragraph: Mastery is not our best stat. Haste is technically better. Despite this, one of the current best-in-slot trinkets for shadow priests is Theralion's Mirror, a trinket with a mastery proc. How the heck is that possible?
To explain this, let's first consider how a typical spellpower proc such as Enchant Weapon - Hurricane works. When Hurricane procs, you get 450 bonus points of haste for 12 seconds. Now, as we discussed before, your DoTs don't automatically benefit from the haste -- you'll need to recast them. In theory, the moment that Hurricane procs, you could recast Vampiric Touch and Devouring Plague immediately to give them the haste benefit. Then, right before the Hurricane proc drops off, you could recast each spell. In this way, both VT and DP will hold the increased value of haste until you refresh them. You could (theoretically) enjoy the haste buff on Vampiric Touch for nearly 27 seconds (12+15) and enjoy the buff on Devouring Plague for nearly 36 seconds (12+24).
(Note that if you've taken the Pain and Suffering talent, Shadow Word: Pain will refresh itself automatically via Mind Flay. This means you don't need to recast it to gain the benefit of temporary haste, spellpower, crit, and mastery buffs. Unfortunately, this also means that the first automatic refresh after the buff drops off will also cause Shadow Word: Pain to lose that temporary buff.)
Because of the complexity of the shadow priest mastery mechanic, we can use this principle to game trinkets with a mastery proc (like Theralion's Mirror and the Talisman of the Sinister Order). The Revelation proc from Theralion's Mirror gives us 1,926 mastery for 20 seconds. Now, the proc rate for Revelation is pretty low (only 10% or so), but that's a good thing (sort of) -- for us to get any real value out of it, we need a Shadow Orb to spend. That sets off a chain reaction of sorts:
- We cast Mind Blast ASAP to generate a higher value for our Empowered Shadows buff. Revelation increases it by about 10.7%.
- Once Empowered Shadows is active, we can start recasting Vampiric Touch and Devouring Plague. Shadow Word: Pain will refresh itself when we start casting Mind Flay afterwards.
- Shortly before the 20-second Revelation buff is about to drop, we can cast Mind Blast again (provided we have at least one Shadow Orb up). This will refresh Empowered Shadows at the higher value, giving us another 15 seconds' worth of buff effect.
- For those next 15 seconds, we'll try to hold off from casting Mind Blast again to keep from overwriting that higher Empowered Shadows value. Shortly before the 15-second higher-value Empowered Shadows buff drops off, we can recast VT and DP. These casts will hold the higher value for their duration, milking even more time out of the trinket's buff.
Of course, reaction time and casting time will probably eat up a good 5 seconds or so of that theoretical benefit. Still, you can see why the trinket is so powerful, even if you're not actively trying to game it. The internal cooldown of Theralion's Mirror is 90 seconds, which is quite long as far as ICDs go, and it does have a low proc rate. But even despite these faults, by gaming the trinket as I explained above, you can easily enjoy some of the proc's benefits for well over half of a given fight.
Are you more interested in watching health bars go down than watching them bounce back up? We've got more for shadow priests, from Shadow Priest 101 to a list of every monster worth mind controlling and strategies for raiding Blackwing Descent.