The Great Gubal Library dungeon guide

Dungeon quick facts

Built by the learned men and women of Sharlayan, the Great Gubal Library is the grandest repository of knowledge in all of Eorzea. Lining its towering shelves are tomes beyond count, gathered from the farthest reaches of the realm. Like the city-state, however, the library was abandoned by its caretakers when they fled to their motherland in the face of Garlean invasion. And now, fifteen years since its doors were sealed, you will be the first soul to set foot within its halls. Your destination is the forbidden section deep within the library, where lies your objective: the fruits of Matoya's research on the aetheric converger.

• Category: Dungeon
• First Appearance: Patch 3.0, *Heavensward*
• Level: 59
• Item Level Requirement: 120
• Party Size: 4man
• Required Quest: Forbidden Knowledge
• Entrance: The Dravanian Hinterlands
• Entrance Coordinates: 28,37
• Region: Dravania

Before queueing

Use the quick facts to check level, item level, party size, required quest, entrance, roulette, and time limit before queueing for The Great Gubal Library.

• Repair gear and meet the listed level/item-level requirements.
• Tell the party if it is your first clear.
• Use the local wiki link for exact duty facts and related articles.

Duty Support

Local wiki data lists Duty Support or NPC options for this duty. Use this mode when you want story pacing, screenshots, or a low-pressure first read of arena mechanics.

• Pero Roggo: Poroggo (Tank or DPS)
• Alphinaud: Academician (Healer or DPS)
• Y'shtola: Archon (DPS)

Boss and mechanic notes

The Great Gubal Library has local boss notes for: Demon Tome, Byblos, The Everliving Bibliotaph. These notes are pulled from the local wiki and should be treated as source-backed prep unless separately marked as human-reviewed strategy.

• Like the Demon Wall, the Demon Tome will cast an AoE down the middle of the room, then the sides. If this hits you, it will have a slowing effect, making it harder to get past him for Disclosure.
• As he is between casting the two previous attacks, the Demon Tome will also cast Dark Blizzard III, a circle AoE that will target a random player.
• The Demon Tome will occasionally cast Disclosure and "begin to glow." This signals that you need to run along the sides of the arena to the backs-side of the Tome. Anyone on the wrong side of it when it closes will be killed instantly.
• The Demon Tome will cast Words of Winter after a while, an attack similar to Shiva's ground freeze - when the ground is frozen, you will move a certain length in the direction you attempt to go. Unlike Shiva, this is not all the way to the edge of the arena; it is a matter of several yalms. At that point it will always be active when it casts Disclosure.
• At intervals, Byblos will run to the center of the book that summoned him and become invincible. Shortly after, two books will spawn with adds in them. They will fire Death Ray, a low damage line AoE that extends pretty far. Kill the adds quickly. When they die, they will draw a tether between them and a given player (like the ice, fire, and lightning orbs in the Scylla encounter in The Labyrinth of the Ancients). Draw this orb into Byblos to break his invulnerability.
• After one invulnerability phase, Byblos will begin spawning clouds of oil fumes around the room. These will cause 2k damage and a pushback when you run through them, so take them in turns, carefully, to keep them from stacking up. The clouds will break the orbs from the invulnerability phase if they collide, requiring your party to deal with another set of adds.
• Performs Gale Cut fairly regularly, a frontal attack that deals mild damage to tanks. This has no ground warning, and can be avoided by either running through or to the side. It has a cast time of around 2.5-3 seconds.
• Performs Tail Swipe when someone is behind him, a rear-facing conal attack. This seems to only happen if someone is behind him.
• Performs Head Down on a random party member, which is a fairly damaging charge attack/sort-of stun. This cannot be avoided regardless of any attempt to move away from it and it will hit all party members in its path. If he targets you, try to line yourself up with your party, as this damage is shared evenly between everyone hit.
• At 3 intervals throughout the fight (roughly 85%, 55%, and 25% HP), Bibliotaph will begin casting Void Summon. Platforms on the ground will light up, and they will need a certain number of players to stand on them in order to cancel their summon. When one light on the platform is lit up, only one player is needed to stand on it to cancel the summon. When two lights on the platform are lit, two players must stand on it. When three lights are lit, the platform needs three players. Before this fight, figure out who will go with who for the first two phases, and plan to run all together for the final (three-person) phase. If a platform's summon is not canceled, that platform will summon a voidsent add to the boss fight. Specifically, 1-person platforms will summon a Bibliophile, 2-person platforms will summon a Bibliomancer, and 3-person platforms will summon a Biblioklept.
• At intervals, Bibliotaph will mark players with targets. If you are targeted, run to one side of the arena between platforms to bait the AoE he will place on you.
• This sets down a purple void spark (a stationary ball) which will remain in place for a duration, periodically pulsing to inflict a stack of vulnerability on those in the area. Be sure to avoid this at all costs.
• After the 2nd Void Summon at roughly 55% HP, he will begin casting Deep Darkness which covers the entire outside of the arena, immediately followed by Magic Burst (occasionally he will cast Magic Burst first), which covers the inside of the arena. Deep Darkness hits tanks for around 3k and causes a 25-30 second Heavy debuff. Magic Burst deals damage and a knockback.

Duty finder and rewards context

Use this section to decide whether the duty belongs in roulettes, high-end queues, mentor roulette, or repeat farming.

• Duty Finder: Dungeons (Heavensward)
• Roulette: leveling
• Modes: duty support, explorer
• Time Limit: 90

Completion notes

After your first clear, check whether the duty has mapping, clear, Blue Mage, loot, music, or collection reasons to return.

• Achievement: Mapping the Realm: Great Gubal Library
• Music: Main: Ink Long Dry
• Music: Mid-Bosses: To the Fore|roll=n
• Music: Final Boss: Ominous Prognisticks

Verification boundary

This page is generated from local TJPedia wiki data. It does not invent missing mechanics, NPC coordinates, loot tables, or current-party-finder strategies. High-end positioning and current-prog tactics still need human review before being labeled as a full strategy guide.

• Source-backed: duty facts, local boss notes, achievements, and music.
• Needs human review: exact high-end progression strategy.
• Use official patch notes for changed requirements or rewards.

Related on TJPedia

Wiki: The Great Gubal LibraryDungeon route indexTrial and raid routeGuides hub