Starting at the top of Arcane, it's obvious fairly straight off that overcoming resistances is a priority for this build. Between 4/5 Arcane Focus and 2/2 Arcane Subtlety, targets now have 10 less resistance to all schools and an 8% lower chance to resist Arcane spells (as well as less threat being done from Arcane, though based on the spells he casts I don't think that should have much effect). Note that, due to the dual nature of resists in WoW, these two talents apply to two different kinds of thing. Arcane Subtlety does the same thing as spell penetration gear: it acts as if your opponents had lower resist scores. If I have 30 Frost resist and I'm fighting Xykon, as far as he's concerned, I now have 22 Frost resist.
This is the kind of resistance that causes partial resists ("Your Fire Blast hits Examplename for 720 (212 resisted)"). Of course, to make things confusing, some spells are "binary," which means they can't get partially resisted -- they either hit fully or not at all. If resistance causes a binary spell to be resisted, all you see is "resisted" in your combat log. Generally speaking, binary spells are ones with an added component besides damage, like Frostbolt's slowing effect.
However, Arcane Focus does the same thing as spell hit gear, which applies to a completely different kind of resistance. Essentially, it reduces your chance to miss with spells. For all the mind-numbingly mathy details, check out my post on "Attack Tables and You," but in short: where a physical damage attack might have said "miss," a magical attack says "resisted." These sorts of resists are always complete (not partial), and are based on level. A level 70 caster has an 83% base chance to hit a level 73 mob (like a raid boss) with spells, so any amount of +spell hit up to 17% from gears or talents is useful in increasing DPS.
Next we have Arcane Concentration, which is a core Mage talent for many builds, and Magic Absorption, which reads like a PvP talent to me and probably achieves its stated goal of increasing survivability. However, its numbers feel a bit low, and when you're getting hit, as a mage, is not usually when you're trying to get mana back; I might try to work around including this talent on the grounds that I could get more DPS out of other talents, and the best path to survivability is to kill stuff real fast.
Moving along: Magic Attunement. Hm. Two of the least-used buffs in the game, Amplify and Dampen Magic seem generally useless -- until they're really useful, like on the Curator fight. So this is definitely a niche talent, although if you're doing enough encounters for which Amp/Damp Magic help, this is probably worth taking for the time being. Still, another candidate for shuffling points out of. Improved Counterspell, by contrast, is one of the best PvP talents in the game, and quite useful in other situations. Definitely a good call to take it here.
Now, passing the halfway point of the Arcane tree, we really get to the meat of its "boost everything" potential. Presence of Mind lets you make anything instant (as if Mages didn't have enough instants already). Formidable in PvP, valuable in PvE. Arcane Mind boosts Intellect, which is even better than boosting mana directly, since you get extra crit as well (and benefit from Mind Mastery later on). Arcane Instability blows my 1% benchmark out of the water, by giving 1% damage and 1% chance to crit per point -- and based on some of the talents to come, 1% to crit is going to be worth considerably more than 1% damage. Continuing on the crit front, Arcane Potency works out to roughly 3% chance to crit per point.
The next batch of talents increase damage more directly. Arcane Power, along with Presence of Mind, leads to the "three minute Mage:" every three minutes, you can have an instant-cast, 30% bigger version of whatever you want. Sweet. Right next to it is Spell Power, which, although it took me a little while to figure out the math, ends up making your spell crits do 175% damage (untalented, spell crits do 150% damage, of course). This makes all the crit chance we've been pumping up that much more valuable. And we finish Arcane with a talent that blew me away the first time I saw it: Mind Mastery. Increasing your spell damage based on your Int is a great concept, taking Mages' most important stat and giving them more out of it. Great stuff.
Frost time! Although for the leveling and PvP Mage Frost's calling card has historically been its amazing potential for control, here we're mostly going to be taking it for its damage abilities. Improved Frostbolt is a no-brainer; I'm not sure I've ever seen a Mage build that didn't take 5/5 in Imp Frostbolt or Imp Fireball (with the exception of those that used Arcane for primary nukes). Imp Frost Nova is something I probably wouldn't take on its own, but it's required for Shatter. And Ice Shards stacks with Spell Power to make the crits from this build over the top: now they do 215% damage. Frostbite, to give our Frostbolts a chance to freeze, is going to help us out in a minute.
I'm sure Cold Snap is useful in all sorts of situations, like a Rogue's preparation, although I know it's a lot less useful in 2.1. Ice Block is going to give the "Hypothermia" debuff for 30s, which prevents Ice Blocking again. It's like a Priest's Weakened Soul effect (from Power Word: Shield). So this means no more Ice Block -> Cold Snap -> Ice Block. However, Ice Block is still on a five minute cooldown, which will give plenty of opportunities to Cold Snap out of it.
Moving right along, in a certain sense, the talent this build is built around: Shatter. Crit chance against frozen targets is increased by 50%. This means that if your target has been frozen, by Frost Nova, melee against Frost Armor, or a Frostbite proc (see? Frostbite is good), your next spell will probably crit. There's a bit of a catch, though.
As Xykon points out in his email, in 2.11 or 2.12 Blizzard changed crits against frozen targets, in that any crit from any source now breaks the freeze affect on a frozen target. This means that I frost nova a Mob and freeze it in place, once I crit the target it will break the freeze preventing multiple crits in this fashion. There is one loophole around this however. If you stand somewhere between 10-25 yards away from the frozen target, and cast a frostbolt at it and immediately cast ice-lance afterwards, it is possible for them to both crit. This is because ice-lance is a faster spell which allows it to hit the target simultaneously with the earlier cast frost nova. It is this play style that this build is optimized to take advantage of when soloing.
There's a bit of good news in regard to frozen targets for 2.1:
- Chance to break crowd control from damage: The increased chance for
a spell to break from taking a critical strike has been removed.
Instead, all targets over level 60 have a slightly larger chance to
break out of crowd-controlling effects when they take damage.
As far as I can make out, this is good news for Shatter, except possibly in raids, where people are going to be constantly beating on the mobs and probably breaking Frozen pretty quick.
And of course, at the end of any 21 points in Frost is Ice Block. I stand by my assertion that Mages currently have a tendency to pull aggro, and when they do, Ice Block tends to save their biscuit. It's also immeasurably useful in PvP to be temporarily immune to damage.
Overall, I like this build a lot. In fact, I like it so much that if I ever level my own poor little mage to 70, I might spec him heavy arcane. There's a few talents I don't really like in Arcane, and I don't believe as Xykon does that "arcane focus and arcane subtlety greatly reduces the times when my sheep will prematurely break." I'm pretty sure that those talents only help keep Polymorph from getting resisted in the first place, and have nothing to do with the time it lasts -- am I wrong? Please do let me know.
Upon trying to re-organize this build, I found that all the talents he took that seem iffy to me are more or less required filler for getting deeper in the tree anyway. Therefore I conclude that I have no improvements to suggest for this build. But I'm sure you guys do! Take it away, comments section. And don't forget to email your builds for next week's episode to me at firstname.lastname@example.org
, with a link to the talents (Armory, Blizzard's calculator, or Wowhead's) and an explanation of your goals and anything else you care to mention about the build.