BG3: How to Reach the Underdark (Easiest Entrance)

There are several ways into the Underdark, but the Goblin Camp route is the simplest — no tough boss required. Here’s the path through the Shattered Sanctum and the moon-dial puzzle solution.

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Short Answer

The easiest Underdark entrance is through the Goblin Camp’s Shattered Sanctum. Head to the west side of the Sanctum — either squeeze a small/gnome-shaped character through the hole, or (easier) lockpick the right-hand door (or use the priestess’s key) to reach the Defiled Temple. At the moon-dial puzzle, rotate the rings so all four white dots sit on top and all four black dots on the bottom; the door unlocks and a cutscene drops you into the Underdark near the Selûnite Outpost.

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Key Takeaways

• Use the Goblin Camp / Shattered Sanctum entrance — no major boss fight required.
• Teleport to the Goblin Camp, go through the big oak doors, and head to the west point.
• Option A: transform a character to small/gnome size to crawl through a hole (not all party can).
• Option B (easier): lockpick the right door or use the priestess’s key — everyone gets through.
• The Defiled Temple moon puzzle: arrange 4 white dots on top, 4 black dots on the bottom.
• Solving it opens the door and plays the Underdark cutscene (Selûnite Outpost).

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What’s the Route Through the Shattered Sanctum?

Enter the Goblin Camp, go through the oak doors, and head west to the Defiled Temple. Teleport to the Goblin Camp, pass through the big oak doors into the Shattered Sanctum, and make your way to the west point on the map. There are two ways forward:

• The hole (Option A): on the left is a small hole you can crawl through — but only with a small-sized character (transform one into a gnome). Not all party members fit, so it’s a partial solution.
• The door (Option B, recommended): the right-hand door can be lockpicked, or opened with the key from the priestess (kill her for it if you want her loot). This takes everyone to the same place. You can climb a ladder to avoid the boss or fight her for loot, then follow the hallway down to the puzzle.

How Do You Solve the Defiled Temple Moon Puzzle?

Rotate the dial so all white dots are on top and all black dots are on the bottom. At the moon-dial, you move the rings of dots. The solution is simple: line up so that the four white dots all sit on top and the four black dots all sit on the bottom. Once they’re sorted, the new door unlocks — go through it to trigger the Underdark cutscene and arrive safely.

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FAQ

What’s the easiest way to reach the Underdark in BG3?

Through the Goblin Camp’s Shattered Sanctum — go to the west side, reach the Defiled Temple, and solve the moon-dial puzzle. No major boss fight is needed.

How do you get past the hole in the Shattered Sanctum?

Either shapeshift a character to a small/gnome size to crawl through, or — easier for the whole party — lockpick the right-hand door or use the priestess’s key.

How do you solve the Defiled Temple moon puzzle?

Rotate the dial so all four white dots are on top and all four black dots are on the bottom. That unlocks the door to the Underdark.

Where do you end up after the puzzle?

A cutscene drops you into the Underdark near the Selûnite Outpost — a safe early-game landing spot.

Do you have to kill the priestess?

No. You can lockpick the door instead. Killing her just gives you her key and loot as an alternative.

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Related Guides

• How to Recruit Minthara & Save the Grove — handle the Goblin Camp before you drop into the Underdark.
• Power the Arcane Tower Elevator & Disable Turrets — a key Underdark location to tackle next.

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Sources

• Baldur’s Gate 3: How to Reach the Underdark (Easiest Entrance Guide) — original video walkthrough by Fusion Thunder.