You enter The Praetorium, the Imperial stronghold where the Ultima Weapon is housed.

How to Unlock

The Praetorium dungeon is unlocked by the level 50 Main Scenario Quest The Ultimate Weapon.

A Note About Unskippable Cutscenes

This dungeon is one of a small number of duties in Final Fantasy XIV that contains unskippable cutscenes. Because of this, this dungeon may take longer to complete than other dungeons. During these cutscenes, the dialogue will advance automatically and cannot be skipped.

Arrive at the Command Chamber

Defeat the enemies ahead, then use the Magitek Terminal to move to the next area. Defeat the enemies to open the path. Be careful of the many attack markers to dodge as you proceed through this area. At the end, use the Magitek Transporter to move to the next area. Then enter the boss area and there will be an unskippable cutscene.

Mark II Magitek Colossus

Ceruleum Vent damages all players.

Prototype Laser Alpha creates four circle attack markers in the center, followed by another set of four next to the first four that appeared. Go to one of the safe corners to avoid getting hit.

Prototype Laser Beta targets all players with a circle marker. Avoid overlapping other players with your circle.

Grand Sword is large cone attack that targets a random player.

Arrive at the Laboratorium Primium

Go to the Magitek Terminal and use it to move on to the next area.

Go to the Magitek Armor at the wall of blinking red lights and use the Magitek Armor to get in. Use the hotbar/crossbar actions to hit the enemies in the path. Then move on to the next area. Kill the enemies in the way to open the path. At the end, use the hotbar/crossbar actions to kill the Cermet Bulkhead. There will be an unskippable cutscene.

Go forward to the boss area and there will be another unskippable cutscene.

Nero tol Scaeva

The outer edge will become electrified. You will take damage if you step in it, and will be afflicted by a 15 second Electrocution status.

Spine Shatter does high damage to the player highest in the enmity list.

Augmented Shatter places a stack marker on a random player. All players should stack together with the marked player to spread the damage.

Iron Uprising is a cone attack.

He casts Activate, which summons a Magitek Death Claw that tethers to a random player. The claw will attack the tethered player with The Hand, knocking the player back a long distance. Players should try to quickly kill the Magitek Death Claw.

Nero will sometimes dash to an edge of the area and cast, Augmented Uprising, a large cone attack.

Augmented Suffering knocks all players back from the center. Go toward the center or use a knockback-prevention move such as Arm's Length or Surecast to avoid getting knocked into the electrified edge of the area.

Wheel of Suffering is a circle attack centered on the boss that knocks back players that are hit with it.

After you defeat Nero, there is an unskippable cutscene.

Arrive on the Echelon

Go west and use the Magitek Terminal in the next room. There will be an unskippable cutscene.

Gaius van Baelsar

Horrida Bella damages all players.

Terminus Est creates three floating Xs, each of which casts a line attack. Don't be in front of where the Xs are curved toward.

Gaius casts Phantasmata, creating duplicates of himself, each of which creates a floating X that will cast Terminus Est. Go into one of the safe areas between where the Xs will hit.

Festina Lente marks a random player with a stack marker. Players should stack together with the marked player to spread the damage.

Innocence is a high-damage attack on the player highest on the enmity list.

Ductus causes circle attack markers to move in lines along the area. The outer lines move in the same direction, while the inner line moves in the opposite direction. Go to the end of the platform that the inner line is moving toward, then move to the outer edge to avoid the inner circle attacks.

Hand of the Empire marks all players with a circle marker. Don't overlap your circle with other players.

Four Phantom Gaiuses appear. Gaius will charge his Blade Energy while the phantoms are alive. Kill the phantoms quickly to minimize how much Blade Energy Gaius stores. At the same time, you will have to dodge the attacks that you have seen throughout the fight. Each Phantom Gaius will periodically casts Heirsbane, damaging a random player.

After a while, Gaius casts Veni Vidi Vici, which does more damage depending on how much Blade Energy he stored. If he stored too much before you defeated the Phantom Gaiuses, you will not survive.

Afterward, there is a cutscene, and The Porta Decumana is unlocked.

Completing the Quest

Defeating Lahabrea will complete one of the quest objectives for the Main Scenario Quest The Ultimate Weapon.