Frostbite (mage talent)

Frostbite is a mage talent in the frost tree that gives your chill effects a 5% chance per rank to also freeze your target for 5 seconds, up to a maximum of 15% at rank 3. Mage spells that have chill components include Frostbolt, Cone of Cold, Frost Armor and Ice Armor, and Blizzard if talented with Improved Blizzard.

Frostbite is popular in frost and elementalist talent builds that use Shatter. The freeze effect grants more chances to crit via that talent. Since mobs and bosses in raid situations are often immune to freeze effects, frostbite is not as effective in those situations. It is more effective in solo PvE and PvP situations.

Tips and tricks
In PvP situations Frostbite is effective at catching runners or slowing large groups, which is valuable in Warsong Gulch. Two effective ways to get a Frostbite are with Frostbolt (Rank 1) and Improved Blizzard (Rank 1). With Frostbolt (Rank 1), the cast time is 1 second with full Improved Frostbolt and 1.5 seconds untalented, allowing the mage to rifle them off quickly with the hope of landing a Frostbite. With Improved Blizzard, each tick of the AoE applies a chill, and thus each tick has a chance to Frostbite. Rank 1 is mana efficient enough to chain cast it for a Frostbite hit.

The Frostbite effect does not overwrite the Frost Nova effect or the Water Elemental's Freeze effect. These spells have a longer duration (8 seconds vs. 5 seconds) than Frostbite, and thus supersede it. Even if the Frost Nova or Freeze has fewer than 5 seconds remaining, Frostbite will not take effect. However, if the attack with a chill happens to break the freezing effect, it is possible for the Frosbite freeze to take effect immediately.

Because Frostbite only lasts for 5 seconds, and higher ranks of Frostbolt have a minimum casting time of 2.5 seconds (3.0 seconds untalented), a mage often only has enough time (due to lag) to cast one Frostbolt before the effect wears off. However, if a Troll mage casts Frostbolt in conjunction with the racial Berserking (thus reducing the cast time to 2.25 seconds or less) then he can have up to two chances to crit off a a Frostbite. A mage of at least level 66 can cast the Ice Lance spell instead of additional Frostbolts, as it can allow several castings into a frozen enemy, which is advantageous considering that it does triple damage to frozen targets.

Frostbite is an undesirable talent in frost AoE grinding builds. The goal in a frost AoE situation is to keep a large pack of mobs grouped close together and snared with Cone of Cold and/or Improved Blizzard. If Frostbite lands, it can separate a mob from the pack, complicating the kiting process.