In massively multiplayer online games, an instance is a special area, typically a dungeon, that generates a new copy of the location for each group, or for a certain number of players, that enters the area. Instancing, the general term for the use of this technique, addresses several problems encountered by players in the shared spaces of virtual worlds. It is not widely known when instances were first used in this genre. However, The Realm Online (1996) is sometimes credited as introducing the concept. Design considerations The problem can be stated as follows: every player wants to be "The Hero", slay "The Monster", rescue "The Princess", and obtain "The Magic Sword". When there are thousands of 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 became obvious in the game EverQuest, where several groups of players would compete and sometimes harass each other in the same dungeon, in order to get to the monsters dropping valuable items. The creation of instances largely solves this set of problems, leaving only travelling to and from the dungeon as a potential risk in player versus player environments. Stated another way, instances can be used to reduce the competition over resources within the game. Excessive competition in these spaces leads to several undesirable behaviors such as kill stealing, spawn camping, and ninja looting as players do whatever they can to acquire the limited rewards. Instancing preserves the gaming experience, since some gaming scenarios do not work if the player is continually surrounded by other players, as in a multiplayer setting. Instance dungeons may contain stronger than usual mobs and rare, sought-after equipment. They also may include level restrictions and/or restrict the number of players allowed in each instance to balance gameplay. Several games use instancing to scale the mobs to the players' levels, and/or the number of players present. Despite its advantages, instancing in MMOGs has been criticized. Brad McQuaid, lead designer of EverQuest and Vanguard: Saga of Heroes (both of which did not feature instancing at launch), wrote an essay in 2005 arguing that instances can negatively affect the game's community, virtual economy, churn rate, and other factors. In response to this article, Raph Koster added that instancing should be limited to situations in which the creation of a "pocket zone" makes sense within