An Instance is a separate copy of a building's interior, a dungeon, or some piece of the game's landscape. Instances are created when certain quests are activated or players pass through an instance portal, and allow an individual, Fellowship or Raid to participate in a private adventure. Generally, instances can only be entered by the individual or group that triggered them, and no outside help can be rendered to those within an instance by other adventurers.
Instances allow game developers a greater ability to customize the details of an adventure, including things like weather, events and terrain. The use of Instances means that multiple groups can enjoy highly immersible adventures at the same time without interfering with each others' completion of the quests, or triggering conflict over scarce resources or monsters needed to complete them.
The instanced areas found in the game can be summarized into five categories.
Quest Instances - These instances are only accessible when one or more members of the fellowship have the corresponding quest. They are usually short (5 minutes to 1 hour), very scripted and linear, and the bosses that may be found there do not drop any loot above the uncommon quality (with very rare exceptions). Some require a full fellowship, while others are solo-able. The real reward for completing these is from the quest.
World Instances - This type of instance is not found as often in LOTRO as its quest counterpart, and requires a small or full fellowship if everyone is within the recommended level. World Instances have many quests that lead within, can be completed and repeated, and contain boss encounters that generally drop rare quality and better loot.
Raids - The larger counterpart of World Instances, they are designed for two to four full fellowships of players, and are always raid locked. Completing a boss encounter almost always yields at least one teal-quality item.
Public Dungeons - While they may at first appear to be world instances, this type of instanced location is open to anyone to enter. This means that the separate players and groups that enter will end up in the same instance. Due to the large amount of players that can be found within most, the mob respawn rates are exponentially faster than in a different instance type. Bosses tend to respawn at a very slow rate, and fighting them usually requires less coordination than a world instance boss.
Skirmishes - Introduced with the Siege of Mirkwood expansion, skirmishes allow players of levels 20 and above to instantly enter into combat from anywhere in Middle-earth alongside their Soldier. Level, location and difficulty of the skirmish are all predetermined by the player, and can be adjusted for solo, duo, small fellowship, fellowship and raid group sizes. The battles usually have five different phases and take between 30-90 minutes per completion. The rewards are primarily Marks, which can be traded in to NPCs at Skirmish Camps for a variety of rewards.
- For a list of quests leading into instances, see Instance Quests.