Instance dungeon

In MMORPGs, an instance dungeon is a special area, typically a dungeon, that generates a new copy, or instance, for each group that enters the area. This ensures that there will never be competition (kill stealing, spawn camping) over resources such as mobs within the instance and that player characters experience minimum lag. Instance dungeons may contain stronger than usual mobs and sought-after equipment.

Games that have been known to use instancing include The Realm Online, EverQuest, Anarchy Online, City of Heroes, Everquest2, World of Warcraft, Dark Age of Camelot and Guild Wars. This last one uses instancing extensively to help make the product free of monthly fees.

One game known for not using instance dungeons is EVE Online. Because of the vast amount of space available in the EVE universe, missions for players are created in real space, which any other player could in theory travel to. This allows multiple players to perform the same mission at the same time (in the same manner as an instanced dungeon) but also allows other players to view or participate in the mission, if they discover the location, or if invited to assist by the player who was initially given the mission.

The use of instancing is a hotly debated topic among the MMORPG industry. Brad McQuaid wrote an article on the topic that can be found here: Brad McQuaid on Instancing.