From Mabinogi World Wiki
- Abyss Dungeons are the highest dungeon difficulty, above Advanced. They are described to be "a nightmare world filled with grand and terrifying monsters".
- Abyss Dungeons require at least 1 Expert Talent (Level 11) in order to enter.
- As with all dungeons difficulty levels, Abyss Dungeons require their own unique pass. However, these passes cannot be acquired through an Unrestricted Dungeon Pass.
- Abyss Dungeons transports the player in a similar matter to Shadow Missions.
- The area is considered a Shadow Realm.
- Unlike most other dungeons, this dungeon consists of three large rooms and a boss room in one floor.
- Upon clearing the final wave in the third room, a cutscene will occur and all members will be transported to the final room.
- Monsters in Abyss Dungeons are much stronger than their original counterparts.
- Some may have altered AIs, allowing for a higher aggro range and speed.
- Unlike other dungeons, Abyss Dungeons lack a Dungeon Altar. Instead, players are given a Red Wings of the Goddess that warps them back to the dungeon's lobby.
- Clearing an Abyss Dungeon rewards a Title in addition to the Journal achievement.