Winter's Chill

Winter's Chill is a mage talent that gives the mage's frost spells a chance to apply the "Winter's Chill" effect. Each application of the debuff increases the critical strike chance of all spells cast against the target by 1%. The debuff stacks up to 5 times.

The talent also increases the mage's chance to critically hit with Frostbolt.

This talent is most useful when it is maxed out. Any lower makes it likely that the 'Winter's Chill' will not stack, as not all your spells will be applying it; maxing out the talent means that every frost spell you cast will apply this debuff. Because the effect expires after 15 seconds, a new Winter's Chill must land every 15 seconds to maintain the stack, otherwise it will expire and must be re-stacked.

Winter's Chill versus Improved Scorch
This effect does NOT stack with Improved Scorch which provides the exact same bonus. As such, a single charge of either will not allow the other to be applied to the mob, making mistaken Winter's Chill or Scorch applications costly in terms of raid DPS and time.

A mage must decide which to use in his or her spell rotation. While this would naturally follow one's chosen spec (either Fire or Frost), careful consideration of either Winter's Chill or Improved Scorch may prove very beneficial to one's build and strategy.

Currently, Improved Scorch is preferable to Winter's Chill. That's because Improved Scorch applies the full 5% buff with one hit. On the other hand Winter's Chill can be applied by any Frost damage spell, including Blizzard and Frostfire Bolt, whereas only Scorch applies Improved Scorch.

When it comes to speed of application, Improved Scorch is fully applied with one hit. Blizzard is the fastest way a Frost mage can apply Winter's Chill. Blizzard gives a debuff per damage tick - with its 8 ticks of damage, a single Blizzard is enough to stack all 5 applications for the maximum critical strike bonus.

In terms of debuff duration, Improved Scorch has the advantage. It lasts 30 seconds compared to Winter's Chill's 15 seconds. This means a Fire mage does not have to Scorch often to maintain the debuff or lower his DPS. However, Winter's Chill is refreshed by any Frost spell from a mage with the Winter's Chill talent, making it the easier to maintain of the two debuffs. Because even high-powered, damaging Frost spells can be used to maintain Winter's Chill, a Frost mage will not lose as much DPS as a Fire mage who has to switch to Scorch to refresh Improved Scorch on a target.

That is not to say Scorch and Improved Scorch are completely without advantages. Scorch has excellent DPM and is good for non-solo PvE as it attracts little threat, at the cost of high damage.

Winter's Chill is naturally tied to the other debuffs and advantages of the Frost magic school, namely snares and roots. Spells like Blizzard and Cone of Cold both also have AoEs, with the former being a channeled spell and the latter cast at instant speed.

For parties and raids, in the event another mage is present who uses the talent opposing one's own, communication must be made so that either applications of Winter's Chill or Scorch do not cancel each other out or that the stronger debuff is used.