Frostfire

Frostfire refers to a type of magic wielded by Mages. As the name implies, it takes upon the powers of both Frost and Fire even though these are often the opposite of each other. Frostfire is special as it combines the strengths of these two elements - if an enemy is invulnerable to frost, it will deal fire damage and vice versa. Likewise, it also has the ability to apply both DoT's, which is used by fire spells, and chills, which is used by frost spells.

Spells
Only two spells which makes use of Frostfire magic currently exist:
 * Frostfire Bolt
 * Frostfire Orb

Equipment sets
A few equipment sets refers to Frostfire magic:
 * Inv chest cloth 43.png Frostfire Regalia (removed from game)
 * Inv chest cloth 43.png Heroes' Frostfire Garb
 * Inv chest cloth 43.png Valorous Frostfire Garb

History
"Frostfire" as something used by Mages was first mentioned as the name for the Frostfire Regalia set in vanilla WoW. The mechanic was later implemented in Wrath of the Lich King with the introduction of Frostfire Bolt. The second spell, Frostfire Orb, was introduced in patch 4.0.1 which prepared for Cataclysm.