In World of Warcraft a legendary item is a piece of equipment of extreme rarity and power, a virtual status symbol for those that harness its powers. In SteelSeries gaming mouse parlance, legendary means cheaper with fewer buttons.
The original and Cataclysm editions of the World of Warcraft Gaming Mouse were lovely devices, large, bulky, and sprouting buttons like weeds. So large and sprouting so many buttons that many players found it was too unwieldy and complicated. SteelSeries counters these complaints with the World of Warcraft MMO Gaming Mouse Legendary Edition.