World of Warcraft Instances
Although World of Warcraft is a persistent gameworld, there are areas of the game called instances. These are separate private areas of the game which you enter as an individual or as a party. These areas are usually part of several difficult quests and can be extremely large. Instances in WoW are indicated by swirling portals which can either be blue, green or red. Once you enter the portal, you will see a loading screen and once loaded you or your party will have entered your own special instanced zone.

A blue instance portal
When you enter these areas, a fresh copy of the dungeon is created and populated with monsters. No other players are in this dungeon and only players in your own party may join your instance. Of course, there are other incarnations of the same dunegon where other groups of players are playing but you cannot interact or meet up with these other players when you are in your instance; your instance is your own or party's own private game area. This solves the problems of boss camping and kill stealing which are prevalent in many other MMOs because a copy of the dungeon (instance) is always created on demand for you or your party.

So what happens if you die? [Also see Death guide] Well ideally you would want a party member to resurrect you, this saves you having to make your way back from the nearest graveyard to the entrance of the instanced zone. Instances are usually tied to an extremely hard quest so it is more than likely you'll be in a party. If you're with a Priest, Paladin, Shaman or Warlock then make sure they are prepared to work together and resurrect other players should they die. If you can't be resurrected, then you need to make your way back to the instanced zone from the graveyard. When you enter the instance as a ghost, you are ressurected with half hp/mana inside the entrance of the instance.

So why have instances at all when this is supposed to be an MMORPG where players are all playing together? There is a reason behind instanced zones and that is to make these unique areas manageable for players. With instanced areas harnessing special quests or tougher monsters, it means they don't become overcrowded with different parties all fighting for the same goal. This prevents players in a party having to hang around for monster respawns for example. Instances also prevent the dreaded kill stealing scenario, there is nothing worse than another player taking the kill credit after all your hard work.

Typically, most instances contain Elite quests, so it is advisable to form a group that has at least a healer and a tanker. Players should also try to gather all the quests related to a specific instanced dungeon before trying it otherwise they might have to return to it again at a later stage and repeat the whole dungeon. An average group instance (blue portal) takes between 1 to 3 hours to complete so make sure you have sufficient time. Additionally, players should make sure they have enough inventory space to store any loot that might drop before taking part.

Instances have their own zone chat. Most of the instances themselves are also considered Contested Territory (on the PvP server) but again, some are friendly to the Horde while some are friendly to the Alliance. Even so, which faction the instance belongs to bears no relevance completely. Both factions may enter and play the instances no matter which faction the instance belongs to, and since the 2 factions cannot group with each other, they will never enter the same instance. Still, this could lead to some possible group PvP encounters at the entrance area before the portal.