How to Find the Base Vault Door Code - Horizon Forbidden West Guide - IGN (2024)

While exploring The Base, you can find a locked door behind a vent that needs a door code to open. The Passcode digits are spread out across the Base in Datapoints that you can access as you progress through the story. This page of IGN's Horizon Forbidden West guide details what the Base door code is, how to find the door code numbers, when you can access them, where to find the Secret Vault itself, and what the Secret Vault door code is.

• Where to Find the Secret Vault
• How to Get The Secret Vault Passcode
  • The Games Room
  • The Botany Room
  • The Monitoring Room
  • Locked Basem*nt Room
• The Secret Vault Door Code
  • What's Inside the Secret Vault?

Where to Find the Secret Vault

The Secret Vault is a hidden locked door within The Base, which you first gain access to in "The Eye of the Earth" Interlude Quest.

To find the hidden Base door, from the hub room head through the doorway with a stairs icon above it to reach the Basem*nt, which has a circular arrangement of servers. Here, go through the left-hand door to enter a side room, then crawl through the vent duct directly ahead. When you emerge in the next room, take a right into another duct - just below where you climbed up to get back outside in the Eye of the Earth quest - then go all the way to the end. You'll drop into an open elevator shaft in front of the Vault door!

The Secret Vault's Door Code is gradually unlocked over the course of the game, as GAIA regains power to The Base and is able to open up more rooms.

These rooms will have Datapoints inside them with logs left by Ethan Reed, one of The Base's designers. In each of Ethan's Datapoint logs will be a number dropped in his dialogue. Each of these numbers will be a part of the Secret Vault's Door Code: you'll need to assemble them in the order they were unlocked by GAIA to form the correct code.

The one exception is the fourth Datapoint, which is written by a member of Aloy's team.

The Games Room

• Prerequisite: Return one subservient AI to GAIA.

The first Door Code snippet can be found after you return your first subservient AI to GAIA: either AETHER, POSEIDON or DEMETER. Once you've done this, GAIA will unlock the Games Room, marked with a pink symbol of a chess board above the doorway.

Enter the room and check the back-left corner for a vent cover. Yank it off with the Pullcaster and head inside. Take a right, then a left to emerge in a secret room!

On the table to the right will be Ethan's first Datapoint, "I: A Little Flourish". Examine it, and he'll mention "Regional Control Center 9". That means the first digit of the Door Code is 9!

To leave, head to the back of the room and check the left-hand wall. You can actually interact with it to raise it, taking you right back to the central hub!

The Botany Room

• Prerequisite: Return any two subservient AIs to GAIA

The second Door Code snippet is available after you return any two subservient AIs to GAIA. When you do this, GAIA will unlock the Botany room, marked with a green leaf icon above the doorway.

Here, check the right-hand wall for some shelves with Ethan's next Datapoint, "II: Caterpillars and Chrysalises". In it, Ethan mentions his favourite seed sample, 626. That means the next three digits of the Door code is 626.

The Monitoring Room

• Prerequisite: Return all three subservient AIs to GAIA

The third Door code snippet will be unlocked after you return AETHER, POSEIDON and DEMETER to GAIA. With this, GAIA will unlock a monitoring room down in the Basem*nt. From the stairs down to the Basem*nt, this will be the back-right door.

Head inside and check the back-right corner of the room for Ethan's third Datapoint, "III: The Vault". Towards the end of it, Ethan says that there's 11 more weeks before The Base's blueprints are locked. So, the next two digits are 11.

Aloy may point out that there's a Power Cell socket in the Monitoring room. While this does unlock a Datapoint if you can find one, it actually has nothing to do with the Secret Vault.

Locked Basem*nt Room

• Prerequisite: Complete the "All That Remains" Interlude Quest.

The fourth Door Code snippet is unlocked after you complete the "All That Remains" Interlude Quest. This unlocks access to the locked room on the right-hand side of the Basem*nt room.

Here, check the back-right corner of the room to find this Datapoint next to the hologram of Elizabet. While much of Ethan's fourth Datapoint was lost, a small portion of it was recovered: Ethan's son August was 8 when the Faro Plague broke out. So, the final digit of the Door Code is 8.

The Secret Vault Door Code

Now that you've discovered all four Datapoints, return to the Secret Vault via the vents you can find directly opposite the Locked Basem*nt Room described above. Approach the terminal to input the Door Code for the Secret Vault:

• The Base Secret Vault Door Code: Tap to Reveal

What's Inside the Secret Vault?

Since the contents of the Secret Vault is hidden for much of the game, we consider it to be spoilers. If you really want to know what's behind it, open the Spoiler box below.