Instances (Memorial Dungeons)

An instance is a dungeon that the server copies for each party that wants to go in. The party leader asks for it, the server takes a moment to build it, and from then on only that party can use it until it expires. Inside, an NPC story moves forward in one direction only.

• Each instance has a time limit. If the story is not finished in time, the copy is destroyed and everyone returns to their save point.
• Most have a cooldown before you may enter again. It only applies to members who actually went inside.
• Teleport and Fly Wings do not work, and some instances block other skills. Each has a Base Level requirement, and some need an access quest first.
• You cannot get back in if you leave before the end, die and respawn, or if everyone inside stays disconnected for over 5 minutes. A solo player logged out for more than 5 minutes is sent to the save point.

The iRO wiki sorts instances by how long you wait between runs. A selection, from low to high level:

The Endless Tower is a 100-floor climb where every monster on a floor must die before the door to the next opens, much like the Izlude Arena. A special boss waits on floor 100, with Naght Sieger after it. There is no way back down: you leave by dying, using a Butterfly Wing or stepping into a Warp Portal.

Teleport, Ice Wall, Snatch, Shield Reflect, Fiber Lock, Leap, Extreme Vacuum, Warg Bite, Reflect Damage and Sheltering Bliss are disabled in the tower. MVPs appear on many floors, for example Phreeoni and Maya on 15, Moonlight Flower on 25, Amon Ra and Pharaoh on 50, Dark Lord and Baphomet on 75, Valkyrie Randgris on 90 and Beelzebub on 95. No new memorial dungeon can be created in the 6 hours before War of Emperium until it ends.

Old Glast Heim takes the party back in time to the fall of Glast Heim. It needs Base Level 130, accepts a party of one or more, gives 1 hour 30 minutes to finish and has a 16-hour cooldown. Players mostly farm it for Coagulated Spell, used to get Temporal Boots and their enchants. To start, the party leader talks to Hugin in Glast Heim and opens a Time Gap.

• Floor 1: clear the west wing and find the survivor there, then the east wing (step around the Decomposed Bodies, which call Maggots), then about 85 monsters in the north. The first MVP, Corrupted Soul, then appears; bring protection from Stone Curse and Silence.
• Floor 2: beat the 1st and 2nd Commander of Destruction in the west and east wings, then the final MVP, Amdarais, in the north.
• Rewards: Temporal Crystals and Coagulated Spells, with more on your first clear. Players who got the Amdarais reward can use the fountain on floor 1 to reach a treasure room. Finishing it unlocks Advanced Old Glast Heim.