Instance (World of Warcraft)

Instances, also known as instance dungeons or simply "dungeons", are special areas in World of Warcraft of which many copies can exist at once. "Instance" can also refer to a particular copy of such an area. These areas allow many groups of players to traverse the same geography and battle the same enemies at the same time, without interfering with each other. All instances are accessible by a swirling portal, sometimes blocked by a locked door (and thus requiring a key). The Naxxramas Necropolis provides a small exception to the swirling portal rule by not having one, instead you simply step on a platform located in the Eastern Plaguelands to automatically teleport into the instance.

Instances were first proposed by Richard Garriott in the late 1990s as a way to solve a set of related problems which had become obvious in Ultima Online. The problem is simple to state: everyone wants to be "The Hero" and slay "The Monster", rescue "The Princess" and obtain "The Magic Sword". When there are 2,000 and more players all playing the same game, clearly not everyone can be the hero. The problem of everyone wanting to kill the same monster and gain the best treasure was terribly obvious in the game EverQuest. The creation of instances largely solves this set of problems. There are few examples of boss camping and kill stealing in World of Warcraft - because a copy of the dungeon (instance) is always created on demand for a character or their party.