Prime directive: protect Vault-Tec data!

Masterbrain is a unique robobrain that controls all the other security robots in the Vault-Tec headquarters in the year 2277. It roams the Vault-Tec administration level but is most likely found near a turret control terminal slightly left of the level's center.


The Masterbrain was manufactured for the Vault-Tec Corporation to act as a kill-switch for all other robotic security measures within the headquarters and still remains active 200 years after the Great War. The Masterbrain is identified by the large Vault-Tec logo on its chassis.

Interactions with the player characterEdit

Interactions overviewEdit

General Services Quests
Essential: noIcon cross
Enslavable: noIcon cross
Companion: noIcon cross
Bounty: noIcon cross
Merchant: noIcon cross
Repairman: noIcon cross
Doctor: noIcon cross
Rents bed/room: noIcon cross
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Involved in quests: noIcon cross

Effects of player's actionsEdit

  • If it is defeated and the Lone Wanderer interacts with it, it will say "You have accessed the Masterbrain's internal mechanism. If you destroy its uplink, it will cause all the automated security units in Vault-Tec to shut down." If you choose to do so, this will disable all other robots in the Vault-Tec headquarters building, with the exception of the automated turrets.

Other interactionsEdit

  • The player can shut down Masterbrain using 3 terminals scattered throughout the building. It is also possible to disable it using the Robotics Expert perk.


Apparel Weapon Other items On death
- - - Energy cells
Scrap metal
Fission battery


  • Masterbrain is the only known robobrain without a visible brain.
    • The brain may have been visible before the glass was covered with dirt.
  • Masterbrain appears to have a different color scheme from other robobrains in the Capital Wasteland.
  • The Masterbrain was mentioned in some secret F12 coding hinting at Fallout 4 before its initial release. No one is aware what this meant as the Masterbrain has no connection to Fallout 4.

Notable quotesEdit


The Masterbrain appears only in Fallout 3.