How to unlock the Eureka Orthos deep dungeon in FFXIV (2024)

FFXIV: Endwalker’s patch 6.35 added the third deep dungeon, Eureka Orthos, a laboratory located deep under the Crystal Tower where the Allagan Empire researched immortality, cloning, and dominion over the divine. It’s up to you, the Warrior of Light, to discover the laboratory’s buried secrets and bring them to light.

Deep dungeons are roguelite multi-floor instances that have their own leveling system and items. Defeat the enemies inside to level up and progress to the next floor, and open chests to receive items and upgrade your gear. You can enter the dungeon solo or with up to four people in a party, and you have two save slots to keep your progression.

Continue on to find out where to unlock Eureka Orthos and to learn the differences between it and Heaven-on-High and Palace of the Dead.

In order to unlock Eureka Orthos, you need to meet the following prerequisites:

Once you have those, talk to Koh Rabntah in Mor Dhona to start the quest “Delve into Myth.” If you’re having trouble locating them, check out the image below.

After completing “Delve into Myth,” speak to Khatun in Mor Dhona to enter Eureka Orthos. If you don’t want to travel all the way to Khatun, you can talk to Burnel in Mor Dhona to teleport to the entrance. If you’re having trouble finding either of them, check out the image gallery below to see their locations.

Players will first start at floor one, but you can start at floor 21 if you’ve met the following prerequisites:

In order to unlock the quest “Rage Extinguished,” you must first clear floor 30 of Eureka Orthos. Afterward, speak to Koh Rabntah in Mor Dhona to start the quest.

The major differences between Eureka Orthos and the other deep dungeons are the dread beasts and demiclones. Smaller changes include the name change from a few name changes from pomanders to protomanders, cairns to pillars, and few different protomanders.

Dread beasts are much stronger than the average monster inside Eureka Orthos, but once you defeat one, you’ll receive a buff. Dread beasts can be easily spotted by the glow around them, so keep an eye out for any enemies that have an active animation surrounding them.

Be very careful around dread beasts because they will one shot you in one auto attack. Make sure you have the right protomanders and a high aetherpool level to take one on.

Demiclones take over for Magicites from Heaven-on-High in Eureka Orthos, but they don’t function the same as Magicites. Demiclones will not wipe out the floor, but instead will summon a demiclone to fight alongside you. Each demiclone has their own set of abilities that caters to each of the three roles: DPS, healer, and tank. There is a chance to obtain Demiclones by opening Silver Coffers inside of Eureka Orthos.

Once completing an instance of Eureka Orthos, you’ll receive rewards depending on your level and progress.

If you’re level 90 when you enter, you’ll receive Allagan tomestones and gil based on the floors completed. For more detailed information, check out the table below.

If you’re between levels 81 and 90 when you enter, you’ll receive experience points, gil, and Allagan tomestones of poetics based on the floors completed. For more detailed information, check out the table below.

If you’ve completed the floors above 30, you’ll receive an Orthos aetherpool fragment that can be traded in to the synthesis node in Mor Dhona.

For a full list of the rewards you can get with Orthos aetherpool fragments, check the table below.

Similar to the other deep dungeons, you can keep your aetherpool gear by exchanging Orthos aetherpool grips. If you’ve strengthened your Orthos aetherpool arm and armor to +10, and you’ve completed the sidequest “Rage Extinguished,” you can synthesize an Orthos aetherpool grip which will reduce the strength of your aetherpool arm and armor by 10.