Note: Some of the information below may no longer apply as of the Mists of Panderia expansion.
Frost AOE grinding can be a lot of fun once you get the hang of it. I suggest you practice and start out with only a few mobs. Perhaps 3 or 4, then you can slowly work your way up to 10 or more mobs at once. It’s even more fun to try this on players in battlegrounds ;)
BUFFS & GLYPHS FOR FROST AOE GRINDING
Starting out, its best not to have frost/ice armor on as it has a chance to freeze mobs if and when they hit you. This will make gathering them up a bit harder. If a mob does happen to get rooted you can rally the other mobs around him. To avoid the situation altogether just use mage armor. Add the Glyph of Mage Armor you’ll be regenerating 50% mana while casting as a benefit. This is a great boost to those interested in power leveling anyway as far as your uptime goes. Another great glyph to use in this case is the Glyph of Frost Nova.
Mage Leveling Build for Frost AOE Grinding
At level 40 your frost leveling spec should look something like this 0/0/31 Notice I didn’t pick up improved frostbolt. I would only go for that if leveling including a lot of instances or single target damage, otherwise for aoe purposes its just not needed. If you can afford to dual spec then do it so you can have both an aoe grinding and single target damage spec. You might even have fun making frostfire your single target spec.
No matter which points you pick up in the frost tree the following are essential. All others I would pick up in priority by damage done, and cool downs. Thats unless you find yourself relying on the CDs more. Note, every essential spell I chose below has something to do with either the frost nova or blizzard spells since these are the two main ones mages use most when they AOE grind.
Improved Blizzard – gives a chill effect to your Blizzard which lowers target movement speed. Note the word Chill effect in this part of the tree.
Ice Floes – Ice Floes reduces the cool down on frost nova so it is essential to your build.
Permafrost – Increases the duration of chill effects, reduces movement speed and reduces the target’s healing. Whew! Great for pvp also.
Cold Snap: Cold Snap allows you to reset all of your frost spells. With AOE grinding you want to be able to reset your frost nova and ice barrier especially on a large pack of mobs between CDs.
Frostbite – Increases the chance that your chill effects freeze the target. Nothing is more lovely than to see targets lose the frost nova effect only to be frozen in place once more from blizzard.
Shatter: Can give a boost to critical damage done on frozen targets. Shatter is awesomeness.
Ice Barrier – This is a must have for survivability. It helps while you are running around gathering mobs. The shield not only protects you but it prevents any spell casting interruption.
Ice Shards and Piercing Ice make your blizzard much more powerful so spec them. They increase damage and critical strike chance.
Frost Channelling: Improves your mana efficiency up to 10%. Blizzard is one of the most mana hogging spells on the tree so this will make it cost a bit less.
Precision – reduces mana cost and increases your chance to hit.
Icy Veins – increases spell casting and come quite in handy.
One spell to avoid is shattered barrier however, as it has the chance to freeze any mobs that hit you if your ice barrier wears off.
THE STEPS IN FROST AOE GRINDING
Please note there is no one way to do this, you may see other variations of this or make some of your own. The following is just a description of the basics.
1) Cast Ice barrier then round up mobs on your mount or on foot, whichever suits you. If on foot you can use ice lance to tag mobs that are a bit farther away while running about.
2) Once you’ve rounded them up, cast frost nova
3) blink away
4) Blizzard your heart out but keep it in mind that the mobs will soon unfreeze and walk towards you before your blizzard cast is over. Place Blizzard in a spot that is slightly in between you and the mobs so they walk into it. While this is happening they are likely to receive chill effects and be frozen again in place or at least their slow down effects lengthened/reapplied.
5) Once they get closer to you, cast Frost nova
6) blink, then blizzard again.
7) finish them off with your instant cast spells such cone of cold, arcane explosion, fireblast, ice lance etc. All mobs should be dead at this point
As far as nailing this down, practice makes perfect. You will get better at if if you learn not to bite off more than you can chew and improve at keeping a good distance between yourself and all the mobs.