Vault-Tec Headquarters

The Vault-Tec headquarters building is located in the Vernon Square area of the Washington, D.C. ruins.

Layout
This DC office building is located east of a Vernon Square metro station.

Building history
This was Vault-Tec's base of operations around the DC area. From this location (specifically, by accessing the Vault-Tec mainframe), one can learn the locations of Vaults 87, 92, 101, 106, and 108.

Accessing the mainframe requires authorization from all three system operation terminals. Station 3 is on the first floor of the administration room, with terminals 1 and 2 upstairs of the facility.

Enemies
Resistance inside the building consists of security robots and automated turrets; the models inside are regular protectrons, sentry bots, robobrains, Mister Gutsies, automated turrets and one special model of the robobrain - the Masterbrain - on the same floor as the mainframe. One can turn off the Masterbrain and all other security robots in the Vault-Tec headquarters by using the correct command on the three employee terminals in the mainframe area. Alternatively, one can destroy Masterbrain and use it to shut off all other security robots.

Super mutants have been encountered fighting the robots in the guest relations area. It seems they have been using the Vault-Tec headquarters as a massing point, as gore bags, which are a common find within super mutant bases, are located in the guest relations men's restrooms.

Related quests
Agatha's Song: The vault locations retrieved here help with the optional portion of the quest.

Appearances
The Vault-Tec headquarters appears only in Fallout 3.

Bugs

 * It is entirely possible that once you've killed the Masterbrain, and attempted to shut down all other robots, that all other robots and turrets will remain active and hostile.
 * It is possible to get double XP by destroying all robots then by using Masterbrain to shut everything down, on the player character's way back/out all the robots killed will have 1 bar of HP. Shoot them again and the player characters will get the XP again. Robots you have vaporized or melted with energy weapons will not be revived but their inventories will be broken.
 * It is extremely likely (the player character has already finished Agatha's quest) that the door which leads to the mainframe can't be opened, even the player character manages to get the right authorization from all three System Operation terminals. The mainframe terminal can still be accessed by entering the first floor of the mainframe room and jumping on to the pipe coming out of the wall in the south east corner of the room. From there it is possible to jump onto the computer on the south wall. Then, looking up at the terminal overhead, jump and access the terminal while in the air. Alternatively, the door can be opened with the "unlock"-command when selected in the console.
 * There is a shopping cart outside the building located in between the vending machine and the entrance which, when brought to a specific spot, will disappear and reappear several times, depending on where your player character is facing.