World of Warcraft, also known by the acronym WoW, is a 2004 action MMORPG video game developed by Blizzard Entertainment and published by Vivendi Universal for Microsoft Windows and macOS. World of Warcraft is the most played MMORPG in the world, with approximately 5.2 million active registrations as of October 2017.
Intent on establishing themselves in Durotar, Thrall's Horde has expanded its ranks by inviting undead outcasts to join Orcs, Tauren, and Trolls. Meanwhile, dwarves, gnomes, and ancient night elves gave their allegiance to the Alliance, led by the human kingdom of Stormwind. After King Varian Wrynn mysteriously disappeared, the Great Warrior Bolvar Domadraghi takes his place as regent, but his service was influenced by the mind-controlled black dragon Onyxia, who reigned incognito as a human noblewoman named Lady Katana Prestor. As the heroes investigated Onyxia's manipulations, the ancient elemental firelord Ragnaros reemerged to threaten both the Horde and the Alliance. The heroes of both factions unite and together they defeat Onyxia and send Ragnaros back to the Elemental Plane.