Instanced Zone
From EQ KnowledgePit
[edit] General Information
The term instanced zone, or simply instance, refers to any circumstance in which a group or raid gets their own "copy" of the zone. Nowadays, nearly all progression missions and raids take place in instances. All end-game raid zones in recent expansions take place in instances; this avoids the issues experienced with guilds blocking one another in Veeshan's Peak, the Temple of Veeshan, Vex Thal, and the Plane of Time (before it was revamped to use the expedition system of instancing).
Most (all?) instances are encapsulated by an adventure (in the case of LDoN), expedition, or mission. This prevents unnecessary server load caused by solo players all getting their own instances, as most instanced quests require a group of at least three.
[edit] Solo instances
While almost all instances require a group of three players to get, there are some that can be started by a solo adventurer:
