"Ding" is an exclamation used by players of MMORPGs to indicate that their character has just leveled. As with most MMORPG terms and conventions, "ding" originated in the game EverQuest because of the ding-like sound that accompanies a character's advancing in level. Still used in games like World of WarCraft, despite the fact that leveling in WoW does not cause a "ding" sound to play.