- Travel to Dagoth-Ur.
- Defeat the Vampire located inside a large room on the northwest.
- Loot the Mithril Key from the Vampire's corpse.
- Collect all the five keys on the Second Level.
- Open the doors to the Third Level.
- Retrieve the Final Piece of the Staff of Chaos.
- Resist Fire, useful against Fire Daemons, Wraiths, Vampires and Hell Hounds. Two or three are enough.
- Resist Shock, very useful against Liches and Homunculus. Two are enough.
- Levitate, will be extremely useful during the Third Level to fly above the lava. Very recommended. Two are enough.
- Cure Paralysis, useful against Medusas. Potion is called Potion of Free Action, one is enough.
- Passwall, this will make the Second Level much shorter. It is necessary at least eight times. (The Eternal Champion may get locked inside the Second Level if they do not have sufficient enchantments or magicka to use Passwall eight times)
Dagoth-Ur is the volcano located on the center of the island of Vvardenfell. Common features includes much lava—more than any other dungeon in the Main Quest—and some of the most powerful creatures encountered in The Elder Scrolls: Arena, such as Liches and Vampires, but also Stone Golems, Wraiths, Ghosts, Hell Hounds, and Homonculi. The Final Piece of the Staff of Chaos remains inside the corridors of this dungeon.
The First Level is a large zone with confusing passageways, but fortunately the door to the Second Level is not far away from the entrance. The fastest way to reach the next zone is to go west immediately after entering the dungeon, fighting with Hell Hounds, Homonculi, and Wraiths.
The door to the Second Level is locked, and the Mithril Key which opens it is guarded by a Vampire inside the room close to the door, in the northwest zone. The room is also locked, but it is possible to open it using an unlocking spell or simply attacking it. It is important to remember that Vampires are the second strongest creature encountered, having power to deal massive damage with his sword or with Fireballs.
After defeating the Vampire, the Mithril Key can be looted from his corpse and used to open the Second Level's entrance.
The Second Level is also a large area, however this time the Eternal Champion will have to explore all of it. The entrance to the Third Level is protected by five doors, each one has a corresponding key located in different zones of the Second Level, they are the Ruby Key, the Sapphire Key, the Crystal Key, the Amethyst Key and the Diamond Key.
However, if the Eternal Champion has the effect Passwall, either by spell or enchantment, they can break the walls and open only the last door with the Diamond Key, which is found close to the center of the Second Level and is protected by a Lich near an abyss (see map).
The Ruby Key is above a platform surrounded by lava inside a large room located in the northwest zone. An Iron Golem will be protecting this key. The Sapphire Key is also located above a platform surrounded by lava protected by a Fire Daemon, this time in the northeast zone of the map. This location can be only reached through a hidden passage or by using Passwall. The Amethyst Key is also above a platform in the southeast zone, guarded by a Vampire, however this one is surrounded by an abyss. As mentioned previously, the Diamond Key is protected by a Lich near the center of the Second Level, and the Crystal Key is located on a room in the southwest with only one entrance, surrounded by lava. To take this key, the Eternal Champion will have to carefully jump over the lava. The key is protected by a Medusa. (all these five keys are represented in the map with white markers).
If the Eternal Champion uses Passwall to break the way, before doing the next step, it is very recommendable to save the game and not to save again on the same slot until getting out of Dagoth-Ur. This is a measure of safety to ensure the Champion will not be locked inside the Second Level.
When the five keys have been obtained, the Eternal Champion must open the doors. After opening the last door, Stone Golems will be protecting the entrance to the Third Level. When they are defeated, the Eternal Champion can enter the last area of Dagoth-Ur, the heart of the volcano.
This level is different from the other two—it is simply composed by one corridor and a large lava lake. The Final Piece stands right in the heart of Dagoth-Ur, surrounded by lava. To reach it, the Eternal Champion must first go through a corridor guarded by Homonculi and Wraiths.
The heart of Dagoth-Ur is the last area of the dungeon and one of the most dangerous places in The Elder Scrolls: Arena. Four Fire Daemons guard the corners of this zone, and three Liches can be encountered next to the walls. Ghosts and Homonculi are seen flying above the platforms surrounded by lava, and more Homonculi are encountered above the central platform where the Final Piece stands.
It is not necessary to fight the Liches nor the Daemons to reach the Final Piece, however defeating them will grant a great quantity of experience points to the Eternal Champion. If the Levitation effect is available, it should be used now to fly above the lava. If the effect is not available, the Eternal Champion will have to jump through the platforms and reach the central platform.
The Final Piece is surrounded by walls and it is a bit difficult to come close to it. The Eternal Champion must stand right in the front of the flying blocks and jump above them (the Levitation effect must not be active; the mouse can be used to adjust the character to the right position). The Eternal Champion will fall inside an abyss and the Final Piece shall be in front of them; they just need to climb up the wall and touch the Final Piece. It will give a riddle before being obtained:
"To escape, a riddle must ye answer...
From the beginning of eternity,
To the end of time and space,
To the beginning of every end,
And the end of every place...
What am I?"
The answer is (humorously) "E."
The Final Piece will then join the pieces collected earlier and finally repair the Staff of Chaos, and the following message will appear to the Eternal Champion.
"Thou art truly worthy. Go in peace,
and let thy fate be written
in the Elder Scrolls..."
The Eternal Champion must now exit Dagoth-Ur, breaking the way again if they used Passwall to skip the Second Level.
The Staff of Chaos is finally completed, however, an unexpected problem is discovered.
For the last time, the usurper Jagar Tharn appears to the Eternal Champion and reveals that before splitting the pieces of the Staff of Chaos around Tamriel, he had drained its magical power. The Imperial Wizard will defy the Eternal Champion to travel to the Imperial Palace in the Imperial Province and meet him personally—if, of course, he survives Tharn's minions, who are sent again in a new ambush.
- In The Elder Scrolls III: Morrowind, the volcano is renamed as Red Mountain, while the Dagoth-Ur refers to a sub-location in the mountain and the main antagonist.
This section contains bugs related to Dagoth-Ur (Quest). Before adding a bug to this list, consider the following:
- If the Eternal Champion uses Passwall to break the way into the Third Level, the walls will reappear and they may get locked inside the Second Level if they cannot use the spell again to exit the dungeon.
- If the Eternal Champion forgets to grab the final piece of the Staff of Chaos, but leaves the abyss holding it anyways, when he goes back to grab it the riddle to leave will not initiate again; not allowing the player to leave the abyss, and effectively breaking the main quest.