Let's look at the first change first. Yes, I came up with that order on my own.
Arcane Blast is stackable up to 4 now, instead of 3. The damage increase per stack remains the same, at 15%. Only the mana cost has changed, and it has actually gone down. Instead of doubling with every stack, it has gone back to something closer to the pre-Wrath era--130%. This means that the mana cost per stack now looks like this:
1st cast: 229 mana
1 stack: 297 mana
2 stacks: 387 mana
3 stacks: 503 mana
4 stacks and beyond: 653 mana
Currently, a fully stacked Arcane Blast costs you 1830 mana. This is an absolutely massive mana reduction for our major nuke. Feel free to correct my math, which was performed by me, a person for whom numbers with more than one digit are confusing and scary.
So once the patch hits, our main nuke won't eat up nearly the amount of mana it does now, and the difference in our mana efficiency should be pretty astonishing. Our staying power will increase dramatically in long fights, and we should find that we can pick and choose when to use Evocation, instead of the current situation, where you absolutely must use it every two minutes without fail, and if you happen to get interrupted during an Evocation, you're reduced to alternating wanding and crying like a little girl until your mana gem cooldown pops.
And it only gets better.
This is the game-changer, right here. My first fear, upon reading this change, was that they'd be taking away the gatling-gun speedy missle effect this talent currently grants. I've since tested it out on the PTR, though, and I can confirm that this is not the case.
Here's the deal: On the PTR, Missile Barrage works exactly the same way that it does on the live server, only with two key differences. The first is that it completely removes the mana cost for the next Arcane Missiles you cast. Yes. I totally just typed that. Your next Arcane Missiles is free. Still fast, still powerful, still fully buffed from the Arcane Blast buff (4 times instead of 3), only also free. I only wish there were a way to italicize that even more than the font we use here at WoW.com allows. I would italicize it to the ground, baby.
The second key difference is that your chances of proccing Missile Barrage go up significantly when you cast Arcane Blast. Instead of the standard 20% chance you get from casting the other applicable spells, Arcane Blast will give you a 40% chance. That's twice the chance, according to my math, or to be more scientific, 200% more awesome. Casting other spells will still grant you the 20% proc chance. Which of course begs the question: why would you cast anything else? You wouldn't, that's the answer. Also, why would you ever, ever cast a non-Missile Barraged Arcane Missiles? Let's weigh the options here:
Option one: Costs a bunch of mana, takes 5 seconds to cast.
Option two: Costs zero mana, takes 2.5 seconds to cast. Also, gives you a back massage and makes you breakfast.
I know which option I'm picking.
So here are the implications for Arcane Mages should these changes make it through the testing process and then not get nerfed 36 hours after the patch drops. Cough.
1. There will be one acceptable spell rotation in PvE: Arcane Blast x 4>Arcane Missiles (if Missile Barrage has procced). If Missile Barrage fails to proc after four consecutive 40% chances for it to do so (and we all know this will happen frequently, thank you random number generation), you will keep casting fully stacked Arcane Blasts until it does, since the mana cost isn't prohibitive to do so.
2. Arcane Barrage will have no further use in PvE, except as a way to continue to DPS on the move. This saddens me, since it's a 51 point talent, and it's an awesome spell, and I love it dearly. I pray they can find a way to make it PvE viable again, but doing so without upsetting the PvP applecart is probably going to be difficult.
3. As mentioned before, mana efficiency will go way, way up, meaning Arcane Mages will have far more leeway in how and when they choose to use Evocation and their mana gems. Long fights will no longer be the chore they currently are, and DPS will increase because we no longer have to reign in our mana usage quite as much.
4. DPS will increase overall. Significantly. I anticipate this change putting Arcane on par with deep Fire, and possibly even surpassing it. The increase from that fourth stack of Arcane Blast alone is huge.
5. In situations where a quick burn is called for, as when a boss is near death, we can now spam Arcane Blast and not run out of mana three seconds later. It'll be sweet. A little boring, but sweet.
6. Warlocks will re-roll en mass, finally discovering that felhunters are ugly and difficult to housebreak, and having them totally doesn't make up for the sad fact that Warlocks aren't Mages. Also, this will only happen in my imagination, where Warlocks do things like this all the time. Other things that happen in my imagination? Frost becomes PvE viable. Everything in the videos on this page. Also, Duckie gets the girl. Every time. My imagination probably needs to be medicated, people.
And holy crap, guys, I'm not even taking into account Glyph of Arcane Blast here. 18% damage increase per stack? Times 4? Multiplied by the power of awesome? That equals yay. Yes, indeed.
Every week Arcane Brilliance teleports you inside the wonderful world of Mages and then hurls a Fireball in your face. Check out our recent three-part guide to PvP for each Mage spec, or our look at what hit rating means to Mages. Until next week, keep the Mage-train a-rollin'.