Frost Mage in action (Source: WoW opening cinematic)
A frost mage is a Mage who mainly invests Talent Points in the Frost tree. Through use of freezing and chill effects, a frost mage is able to keep enemies at range and kite mobs. They possess high-damage single-target spells such as 
[Frostbolt] and 
[Ice Lance]. Frost mages are also well equipped for AoE grinding: through use of 
[Cone of Cold], 
[Frost Nova] and Blizzard, they are capable of dealing significant damage while sustaining very little.
Signature talents
The frost tree has many talents and abilities that improve survivability in PvP and PvE situations. Some popular abilities are:
[Ice Barrier] (Frost, Tier 7) - Instantly shields you, absorbing X damage. Lasts 60 sec. While the shield holds, spells will not be interrupted.- Before patch 2.3.2, [Ice Block] was a tier 5 talent for frost mages. It can now be learned from the trainer by every mage who reached level 30.
Though frost does not have the damage potential that Fire spells do, a number of talents improve frost damage to a respectable level. [Frostbolt] is the frost mage's primary damage tool.
- [Improved Frostbolt] (Frost, Tier 1) - Reduces the casting time of your Frostbolt spell by 0.1/.2/.3/.4/.5 sec.
- [Ice Shards] (Frost, Tier 2) - Increases the critical strike damage bonus of your Frost spells by 20%/40%/60%/80%/100%.
- [Piercing Ice] (Frost, Tier 3) - Increases the damage done by your Frost spells by 2%/4%/6%.
- [Arctic Winds] (Frost, Tier 7) - Increases all Frost damage you cause by 1%/2%/3%/4%/5% and reduces the chance melee and ranged attacks will hit you by 1%/2%/3%/4%/5%.
- [Empowered Frostbolt] (Frost, Tier 8) - Your Frostbolt spell gains an additional 2%/4%/6%/8%/10% of your bonus spell damage effects and an additional 1%/2%/3%/4%/5% chance to critically strike.
- [Icy Veins] (Frost, Tier 3) - Hastens your spellcasting, reducing cast time of all spells by 20% and increases the chance your chilling effects will Freeze the target by 10%. Lasts 20 sec. (3 min cooldown) (Added in patch 2.3.2)
One potent source of mage damage is through frozen targets. At level 64, mages learn the [Ice Lance] spell, which deals considerable damage to frozen targets. Furthermore, through the 
[Shatter] talent, mages can gain a significant chance to crit on frozen targets.
- Frostbite (Frost, Tier 2) - Gives your Chill effects a 5%/10%/15% chance to freeze the target for 5 sec.
- [Improved Frost Nova] (Frost, Tier 2) - Reduces the cooldown of your [Frost Nova] spell by 2/4 sec.
- [Shatter] (Frost, Tier 4) - Increases the critical strike chance of all your spells against frozen targets by 10%/20%/30%/40%/50%.
An important frost mage tactic is frost kiting. Frost mages are capable of kiting single mobs such as certain tough elites, as well as large groups of mobs with AoE. A number of talents improve the mage's chill effects:
- [Permafrost] (Frost, Tier 2) - Increases the duration of your chill effects by 1/2/3 sec and reduces the target's speed by an additional 4%/7%/10%.
- [Improved Blizzard] (Frost, Tier 3) - Adds a chill effect to your [Blizzard] spell. This effect lowers the target's movement speed by 30%/50%/65%. Lasts 1.50 sec.
Solo PvE playstyle
The general efficiency of frost compbined with its survivability make it a decent spec to consider for leveling and general grinding. The Frost mage relies heavily on kiting in solo PvE. The general goal is to keep mobs snared with [Frostbolt] or [Cone of Cold] to keep distance from them, as well as [Frost Nova] to root mobs in place and get to maximum casting range. The mage's primary damage spell will be Frostbolt, but also [Ice Lance] at higher levels.
The general game plan when soloing a standard, non-elite mob is to first pull with Frostbolt, and cast more Frostbolts until the mob is in melee range. Next, the freeze the mob in place with [Frost Nova] and gain distance to repeat with more Frostbolts. Fireblast is also good to mix in when it's cooldown is available. Because it is an instant cast, it can be cast on the run while moving away from the target. [Cone of Cold] is similar in that it is instant and can be cast on the run, and has a stronger snare than Frostbolt. However, it requires melee range and is somewhat less mana efficient, so should be saved for when the stronger snare is necessary.
Frost is well suited to soloing elite level mobs. These mobs normally hit too hard and have too much HP to solo toe to toe. By kiting, the mage can keep the elite at a distance and never take damage, and can deal as much damage as his mana pool can provide.
With frost, it's possible to kite large amounts of mobs at once to greatly increase grinding efficiency. This technique is called frost AoE grinding, and incorporates Cone of Cold, Frost Nova and 
[Blizzard], particularly with the [Improved Blizzard] talent to keep multiple mobs snared and at a distance.
Understanding snares
Only one snare can take effect at a time on a mob, and it is always the one that slows the most. Frostbolt is the weakest frost snare a mage has, apart from 1/3 Improved Blizzard. Cone of Cold is stronger, and with 3 points in Improved Blizzard, Blizzard becomes the strongest. With only 2 points in Improved Blizzard, Cone of Cold is just as strong as Blizzard, which lets these spells overwrite each other. It's important to know which spells have stronger snares than others, because if a stronger one is present then weaker ones will not take effect.
One common example is using Cone of Cold in conjunction with Frostbolt. Frostbolt's snare will not overwrite Cone of Cold even if there is merely one second remaining of the Cone of Cold debuff, as Cone of Cold slows by 10% more. If you cast Frostbolt on a mob afflicted by Cone of Cold, it will do its damage, but once the Cone of Cold debuff wears off, the mob will move at full speed. Similarly, Cone of Cold will not replace a fully-talented (3 points) Improved Blizzard snare, but it will replace 2/3 Improved Blizzard, though, as mentioned, 2/3 Improved Blizzard can also overwrite Cone of Cold.
For reference, here's how much each spell slows by:
| Spell | Snare effect | w/  [Permafrost][1]
|
|---|---|---|
| 1/3 Improved Blizzard | 25% | 35% |
| Frostbolt | 40% | 50% |
| Cone of Cold | 50% | 60% |
| 2/3 Improved Blizzard | 50% | 60% |
| 3/3 Improved Blizzard | 65% | 75% |
- Permafrost adds 4/7/10% to all of these chill effects.
End-game dungeons and raiding
End-game content before the expansion placed a high priority on frost damage for mages, with some enemies being completely immune to fire, such as in Molten Core and Blackwing Lair. As a result the typical pre-expansion end-game mage was very likely to be specialized as a frost mage. This is no longer always the case. With the inclusion of spell penetration, and new raid dungeons such as Ahn'Qiraj and Naxxramas with fewer enemies that are entirely immune to any one school of magic, end-game mages can be found with almost any specialization.
A frost mage will use [Frostbolt] as a primary source of damage in most end-game situations. This spell's DPS is normally lower than 
[Fireball], but many talents in the frost tree boost the damage to a respectable level. 
[Piercing Ice] and 
[Arctic Winds] will directly boost all frost damage by a combined 11.3%. 
[Ice Shards] will boost damage from critical strikes, and [Empowered Frostbolt] and Winter's Chill will increase critical strike chances. Because many bosses are immune to freeze effects, talents such as [Shatter] and 
[Frostbite] are not as important, but are still effective when clearing trash in a dungeon.
Most dungeons have AoE situations that can be handled by any mage, however a frost mage has the added benefit of being able to kite at the same time, improving the chance of surviving these situations.
Frost has good mana efficiency which is further improved by talents 
[Elemental Precision] and 
[Frost Channeling]. This allows a frost mage to focus less on intellect and a deep mana pool in favor of more spell damage and spell crit gear.
In many end-game situations, survivability is a factor as the entire group or raid will be taking damage. Frost mages have extra survivability with the 
[Ice Barrier] and 
[Ice Block] abilities. Ice Block has the added advantage that it can purge most harmful debuff effects, which might not otherwise be purgeable. Some examples are the garotte ability used by Moroes, and the Living Bomb ability used by Baron Geddon.
Finally, the frost mage's Water Elemental is a great source of damage in raid encounters. For 45 seconds it does a good amount of damage, while causing no threat for the mage and only using a small amount of mana for the initial summon. The pet's damage and mana pool scale with the mage's gear, so its damage will increase as gear improves. With 
[Cold Snap], the pet can potentially be summoned twice in a single fight.