“The expansion introduces new factions to the game’s universe: The Blood Elves, former High Elves that now suffer from addiction to magic; the Naga, mutated former Night Elves; the Draenei, the original inhabitants of Draenor, the orc homeworld now known as Outland; and the Pandaren, a race of globetrotting, anthropomorphic pandas. The Frozen Throne follows the quest of the Night Elf warden Maiev Shadowsong to recapture the renegade Illidan Stormrage, Blood Elf prince Kael’thas’ struggle with the Alliance and subsequent service to Illidan, Arthas’ attempt to rescue the Lich King from Illidan’s assault, and Sylvanas Windrunner’s fight for independence.

The Horde campaign is separate from the other three, being a stand-alone story and using more role-playing game mechanics over real-time strategy game mechanics. The campaign chronicles the early days of the Horde’s newly established kingdom from the perspective of the beastmaster hero Rexxar.”

- Source: Wikipedia