Audience
While slightly out of date, this guide may still be useful to a mage in a guild strugglig with some of the Ulduar hard modes.
Guide
Note: This is a bit out of date with all the nerfs, but if you're struggling with a fight you may still want to consider trying one of these builds.
Specifically, as of 3.2 the arcane spec is now the top DPS spec, so keep that in mind if you're reading this.
Addons
From my perspective the must-have Ulduar addons for a mage are:
- Scorchio2: for scorch, living bomb
- Power Auras: for Hot Streak/Missile Barrage/Brain Freeze
- Talented: for why, just see all the hardmode talent specs below
- ActionBarSaver: helps switch hotkeys easily when you respec for a hardmode.) It has been a lifesaver since I can easily reload not just my new talent tree's spells but also any fight-specific macros, and it lets me just use one hotkey for fire and frost wards both. I have my profiles named after the bosses for ease. (/abs restore mimiron, for example)
Fight-Specific Builds
For normal-mode Ulduar progression, my two trees were:
* Fire: 20/51/0 (note: as of 3.2, this would be arcane for many fights)
* Frostfire: 0/53/18
I used the Frostfire build for only Vezax.
Once we got into hardmodes, though, there were some additional builds. Note that these are the 25-man hardmodes, which are tuned much more difficult than the 10-mans -- you may not need to respec for any of the 10-mans unless your guild is struggling on them.
Iron Council (medium)
We prefer using the same build we use later on Freya: Frostfire: 0/51/20
While it doesn't have the +hit talent, it does have the snares and roots to make it trivial to deal with Runemaster last.
Iron Council (hard)
While it might be tempting to go frostfire "because my mana is bad on this fight", remember no dps actually matters until the last mob, so you can just easily evoc at the end of the second mob.
Thorim (hard)
Picking up two points of Magic Absorption in a fire build go a long way to making it easier for healers to keep you alive: Fire: 20/51/0
It's not required of course, but 80 resists mitigates about 13% of the damage done to you.
Mana can be tight on Thorim, so avoid AE'ing -- other classes can do it better and single-target is sufficient for the entire tunnel.
Hodir (hard)
Fire or Frostfire are excellent here, because arcane will get GCD-capped.
Freya (hard)
If mages are snaring:
We have two different builds we use here. One mage goes frost: Frost: 18/0/53 (note: no frostbolt glyph, because you act as the primary slow on Snaplasher and never change targets for the duration)
The others go a specific Frostfire build for added control: Frostfire: 0/51/20 (note: no +hit, no +range)
Mages are not strong DPS on Freya hard anyways, they're useful for control of Snaplasher and the Detonating Lashers. The frost-mage not only has the deep frost snares, but a ranged frostnova.
If your guild is good at Detonators (which you probably will be once you get Freya close to dead), respec to remove Frostbite. It can cause random deaths on Snaplasher and isn't necessary once your guild has full control over the detonator phase.
Mimiron (hard)
With multi-target living bomb, this fight is excellent for fire. Like with Thorim, a build with Magic Absorption is very strong: Fire: 20/51/0
Vezax (hard)
I prefer frost on Vezax both for mana efficiency and for survivability: Ice Barrier is extremely useful during the Animus phase.
One potential build is: Frost: 25/0/46
This build gives up some DPS, taking only 1/5 Chilled to the Bone in exchange for going deeper into Arcane to pick up 5/5 Arcane Mind.
Alternatively, the more straight dps but lower mana build: Frost: 21/0/50
You can go with Glyph of Water Elemental if you want the higher DPS, or Glyph of Ice Barrier for higher survivability in the Animus phase.
Manly on EJ also reports that a straight Frostfire Bolt build works as long as you don't use Living Bomb (and few Pyroblasts other than maybe during Animus.)
The reason I like frost is the added survivability of Magic Absorption and Ice Barrier. And given that frost is only just below elemental shaman levels of damage (they are extremely good on this fight since they're designed to never run OOM anyways so they don't have to respec), I'm not concerned about its dps.
Now that the fight is very easy for us and Arcane has been buffed, I actually am most entertained by being Arcane on this fight, despite being very GCD-capped with sub-1.0 second casts.