Mage Frost Talents Builds

Frost Warding (2 ranks)
Increases the armor and resistances given by your Frost Armor and Ice Armor spells by 15/30%. In addition, gives your Frost Ward a 10% chance to reflect Frost spells and effects while active.
D: No effect.
E: No effect.
S: 168 extra armor at level 60.
C: No effect.
=: Armor is equal to wearing 168 extra armor;
PvP: ***
Raid: *
Level: *
Notes: You do not need the ward on to get the extra armor.

Improved Frostbolt (5 ranks)
Reduces the casting time of your Frostbolt spell by 0.1/.2/.3/.4/.5 sec.
D: Up to a 20% dps increase.
E: No effect.
S: No effect.
C: No effect.
=: No other way to reduce Frostbolt's casting time.
PvP: ****
Raid: ****
Level: ****
Notes: An excellent upgrade to Frostbolt. Note that this makes Rank 1 Frostbolt a 1s cast, which is good to use for quck snares.

Elemental Focus (3 ranks)
Increases chance to hit with Fire and Frost spells by 2/4/6%
D: Up to a 6% dps increase.
E: No effect.
S: No effect.
C: No effect.
=: Equal to +6% hit gear.
PvP: ***
Raid: ****
Level: ***
Notes: Useful for ensuring spells land on higher level foes when levelling up; also reduces resists in raiding and PvP.

Ice Shards (5 ranks)
Increases the critical strike damage bonus of your Frost spells by 20/40/60/80/100%
D: Makes Frost crits for 200% rather than 150%.
E: No effect.
S: No effect.
C: No effect.
=: No other way of obtaining this effect.
PvP: ****
Raid: ****
Level: ***
Notes: A solid
Use With: Shatter

Frostbite (3 ranks)
Gives your Chill effects a 5/10/15% chance to freeze the target for 5 sec.
D: No effect.
E: No effect.
S: No effect.
C: This will proc off of Ice Armor, thus auto-rooting any enemy melee attackers.
=: No other way of obtaining this exact effect. The world drop epic Freezing Band has a weaker reactive-only effect.
PvP: ****
Raid: **
Level: ***
Notes: Good in PvP, not so great in raiding since most bosses are immune to being Frozen. A notable exception is Ragnaros.
Use With: Shatter

Improved Frost Nova (2 ranks)
Reduces the cooldown of your Frost Nova spell by 2/4 sec.
D: No effect.
E: No effect.
S: No effect.
C: Allows you to Frost Nova approximately 20% more often.
=: No other way of reducing Frost Nova's cooldown.
PvP: ****
Raid: **
Level: ***
Notes: Once again, a PvP talent. Most raid bosses are immune to freezes.
Use With: Shatter

Permafrost (3 ranks)
Increases the duration of your Chill effects by 1/2/3 sec and reduces the target's speed by an additional 4/7/10%.
D: No effect.
E: No effect.
S: No effect.
C: Makes all your chills last longer and be stronger.
=: No other way of obtaining this effect.
PvP: ***
Raid: **
Level: **
Notes: Not so great for Frostbolt, since you're typically chain casting Frostbolt anyway. Best used with Improved Blizzard. It's worth noting that it does work on Ice Armor's proc.
Use With: Improved Blizzard

Piercing Ice (3 ranks)
Increases the damage done by your Frost spells by 2/4/6%
D: 6% more damage.
E: No effect.
S: No effect.
C: No effect.
=: However much +dmg gear is equivalent to 6% more.
PvP: ****
Raid: ****
Level: ***
Notes: More damage is good, and this talent applies its multipler to your +dmg gear, which means it scales as your gear gets better.

Cold Snap (1 rank)
Instant/10 min cooldown - When activated, this spell finishes the cooldown on all your Frost spells.
D: No effect.
E: No effect.
S: No effect.
C: Eliminates any remaining time on your Frost spells.
=: No other way of obtaining this effect.
PvP: ****
Raid: ***
Level: ***
Notes: Mostly useful for PvP where an extra Frost Nova/Cone of Cold combo or another Ice Block is most useful. Worth picking up as you go deeper in the Frost tree, as it's a solid talent, althought its own cooldown is somewhat long (10m).
Use With: Ice Block, Ice Barrier, Frost Nova, Cone of Cold

Improved Blizzard (3 ranks)
Adds a chill effect to your Blizzard spell. This effect lowers the target's movement speed by 30/50/65%. Lasts 1.5 sec.
D: No effect.
E: No effect.
S: No effect.
C: This makes Blizzard into the best AoE snare in the game.
=: No other way of obtaining this effect.
PvP: ****
Raid: ***
Level: ***
Notes: Best used in Alterac Valley or other places with tightly clustered groups of enemies (e.g. around Arathi Basin flags or WSG flag rooms). Also has select uses in raids (e.g. can be used in Nefarian's room). Finally, this can be the cornerstone of an AoE kiting levelling build if combined with Permafrost (which makes the snare last 4.5s).
Use With: Permafrost, 5 piece Netherwind set bonus for a truly massive AoE snare

Arctic Reach (2 ranks)
Increases the range of your Frostbolt and Blizzard spells and the radius of your Frost Nova and Cone of Cold spells by 10/20%.
D: Adds 6 yards to your Frost Nova.
E: No effect.
S: No effect.
C: Increases the radius of Frost Nova and Cone of Cold by 20%.
=: No other way of obtaining this effect.
PvP: ****
Raid: ****
Level: ****
Notes: More range is a good thing. This bumps Frostbolt over 30 yards, which is the radius for many raid bosses' area effect abilities.

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Frost Channeling (3 ranks)
Reduces the mana cost of your frost spells by 5/10/15% and reduces threat caused by Frost spells by 10/20/30%.
D: No effect.
E: Frost spells cost 15% less mana.
S: No effect.
C: No effect.
=: This talent is the only way of getting any threat reduction on Frost spells, aside from much smaller reductions possible through some very expensive enchants. Also, this talent is the only way to get any mana cost reduction on Frost spells.
PvP: **
Raid: *****
Level: ***
Notes: A cornerstone of a mana efficient raiding build.

Shatter (5 ranks)
Increases the critical strike chance of all your spells against frozen targets by 10/20/30/40/50%.
D: +50% crit chance vs.
E: No effect.
S: No effect.
C: No effect.
=: No other way of obtaining this effect.
PvP: *****
Raid: **
Level: ***
Notes: Frost's burst dps potential lies around the careful use of this talent. Note that it also works with non-Frost talents. Combine this talent with AoEs and/or +crit talents to obtain near certain crits on frozen targets.
Use With: Frostbite, Improved Cone of Cold, Frost Nova, Blast Wave, Flamestrike, Critical Mass, Arcane Instability, Improved Arcane Explosion, Improved Flamestrike

Ice Block (1 rank)
Instant/5 min cooldown - You become encased in a block of ice, protecting you from all physical attacks and spells for 10 sec, but during that time you cannot attack, move or cast spells.
D: No effect.
E: No effect.
S: 10 seconds of complete immunity.
C: 10 seconds of being unable to do anything; you can right-click on the buff to cancel the Ice Block early
=: No other way of obtaining this effect.
PvP: *****
Raid: ****
Level: **
Notes: You can be healed while Ice Blocked. Thus if you are getting focus-fired, hit Ice Block and wait for a healer to heal you. Then when you get healed, you can drop Ice Block and go back to work.
Use With: Cold Snap

Improved Cone of Cold (3 ranks)
Increases the damage dealt by your Cone of Cold spell by 15/25/35%
D: +35% to Cone of Cold damage
E: No effect.
S: No effect.
C: No effect.
=: However much +dmg gear is equivalent to 35% more damage on Cone of Cold.
PvP: ****
Raid: **
Level: ***
Notes: Useful if you're relying on Nova+CoC combos for burst. If you're just using CoC as another snare, it isn't worth grabbing this talent. Has some use for Frost kiting levelling builds.
Use With: Shatter, Frost Nova

Winter's Chill (5 ranks)
Frost spells cause a debuff that increases chance to crit with frost effects by 1%, which stacks up to 10 times
D: Up to 10% more crits on Frost spells.
E: No effect.
S: No effect.
C: No effect.
=: No other way of obtaining this efefct.
PvP: **
Raid: ****
Level: **
Notes: You want at least one Frost mage to have this talent in your raid.

Ice Barrier (1 rank)
Instant/30 sec cooldown - Instantly shields you, absorbing 818 damage. Lasts 1 min. While the shield holds, spells will not be interrupted. Now stacks with PW: Shield and gains 10% of +Frost dmg gear. Absorb effects now prioritized over Mana Shield.
D: No effect.
E: No effect.
S: Effectively 818 (or more) hit points every 30 seconds.
C: No effect.
=: Very similar to Power Word: Shield, fortunately it stacks with it now (it used to get overwritten by it).
PvP: ****
Raid: ****
Level: **
Notes: It can be dispelled. It gains 10% from any +dmg that affects Frost, thus "Increases damage and healing done by magical spells and effects by up to XX" will affect it.
Use With: Cold Snap