Frost Mage
Rotation
Opener: Frost Armor or Ice Armor, Frostbolt from max range, Frost Nova when they reach you.
Priority: Frostbolt, Frostbolt, Frostbolt. Cone of Cold and Blizzard on packs; Fire Blast when moving; Ice Barrier before pulls.
Cooldowns: Ice Block to drop threat or survive; Cold Snap to reset Ice Block and Ice Barrier; Counterspell on casters.
Forever notes: The leveling and PvP tree, and a fine raid tree where bosses resist fire. Winter's Chill stacks make it the raid pick in Forever if two mages share the work.
Stats
Spell Hit to 16% (Precision covers 6%), Frost spell power, Spell Crit (Shatter), Intellect, then Stamina for PvP.
Frost's crit comes from Shatter on frozen targets, so raw crit matters less than keeping targets frozen.
Numbers for every spec and a gear comparer: stat weights.
Where it ranks
See the tier lists for PvE and PvP placement, and Classic vs Forever changes for what Blizzard altered in this class.
Wowhead and Icy Veins keep spec guides of their own: Icy Veins Frost Mage, Wowhead class guides. Our rotation notes are editorial, written for the Nov 2 tuning.