LotRO allows you to replay instances that you have already done as a repeatable instance, for Skirmish Marks. Each instance is unlocked at a particular level and scales all the way to max level. Some have further restrictions to unlock and may have party size restrictions as well.
These are initiated by opening the Instance Join window (Ctrl-J).
You may also replay many Epic instances by speaking to a Sage at a Reflecting Pool.
For a list of available Skirmishes, see Skirmish.
|Instance: Great Barrow: The Maze<s>||20-65||Fellowship|
|Instance: Great Barrow: Thadûr<s>||22-65||Fellowship|
|Instance: Great Barrow: Sambrog<s>||24-65||Fellowship||Defeat the guardians of The Maze and Thadûr to unlock|