Vault 88

Vault 88 is a Vault-Tec Vault and potential settlement in the Commonwealth in 2287.

Background
Accessed via a small cave beneath Quincy Quarries, this Vault was intended to test various prototype devices with the aim of distributing them to the rest of the Vaults. This Vault was never finished, with only the main entrance, security, and reactor rooms completed when the bombs dropped and the work stopped.

When the Sole Survivor approaches this Vault for the first time, a group of raiders will be trying to force their way in - the event that triggered the emergency broadcast calling for help - and Overseer Barstow will inform the raiders that their efforts are futile.

Once the raiders are dealt with, the Sole Survivor can activate the control panel using their own Pip-Boy to open the Vault door. After that, they can use the control panels inside or outside to open and close the Vault door. When inside, the overseer will ask the Sole Survivor to find the Vault-Tec control board in the reactor room to reactivate the workshop and free her from behind a caved-in corridor.

More building space can be unlocked by finding other control boards, one for each sector of the Vault. Once all of the sectors have been unlocked, the Vault becomes a seamless and expansive workspace, with the only borders being at the Vault's door itself, the subway exterior entrance, and the pharmacy exterior entrance.

Layout
Vault 88 consists of a number of chambers and passageways. In the initial stage of the related questline, the Vault entrance and reactor room are accessible and occupied by a number of leveled feral ghouls, one being Security Chief Andersen. Once the main area's workshop has been unlocked, the player character may then access the main cavern of the Vault, which is an expansive space filled with construction machinery, destroyed trains, and piles of debris. All of these can be scrapped for open space. There are several feral ghouls in the area, as well as a glowing one. One of these feral ghouls is named Julian.

Huge debris piles and limestone walls are in tunnels to the north and east off the main room. Each of these seals off one of the three remaining sectors of the Vault (north, northeast, and east), and once scrapped in workshop mode, will initially reveal a border beyond which the workshop cannot yet access.

After unlocking all three workshops during Explore Vault 88, it will be possible to link each of the three passages by clearing limestone walls between them. Sneak carries over when entering workshop mode, but cannot be activated while already in workshop mode, and it is possible to be rushed and overwhelmed by the enemies that wait beyond as soon as the walls have been cleared.

Starting from the main chamber, the north tunnel passes a mole rat infestation to reach a ruined subway platform area where the north sector control board and several feral ghouls may be found. Through another cave tunnel farther along the platform is the north sector workshop. After activating the workshop, just to the east is a limestone wall that may be scrapped to clear the way to a small cave occupied by a leveled legendary deathclaw. Another limestone wall on the far side of this cave opens near the start of the north tunnel and the main chamber. Throughout the north tunnel and deathclaw cave on the ground, walls, and ceiling are eleven uranium veins providing 61 nuclear material when scrapped, as well as several scrappable uranium barrels in the subway area. The subway platform also includes a wooden barricade at the end; when this is scrapped, access to the manhole entrance near Milton General Hospital will become available. An open tunnel northeast of the north sector workshop connects to the northeast sector and the nearby northeast sector workshop, with a limestone wall blocking further passage to the left.

Starting from the main chamber, the northeast tunnel descends sets of metal stairs and continues past construction supplies and equipment through another area occupied by mole rats. Natural cave passages studded with more uranium veins eventually give way to an area built of brick and concrete hosting several feral ghouls and the northeast sector control board. Through a hole in the wall is another cave passage that soon descends a natural slope to the area with the northeast sector workshop. After activating the workshop, a limestone wall on the northern side of the passage a short distance past the initial metal stairs may be cleared to reveal a nest of seven radscorpions. Another limestone wall past the nest is the wall next to the northeast sector workshop described above. Returning to the brick and concrete area, scrapping the wooden barricade up the stairs will free the feral ghouls beyond it and unlock the University Point Pharmacy entrance. Finally, a limestone wall up a rock face directly east of the initial metal stairs connects to the flooded room with the east sector workshop, the Vault-Tec water pump, and a group of resident mirelurks.

Starting from the main chamber, the east tunnel descends a subway tunnel to a small room at the end on the right with some feral ghouls and the east sector control board. Crossing to the parallel tunnel to the north and continuing to descend to the east leads to the room with the east sector workshop. After activating the workshop, a hole in the southern wall of the control board room opens to a small natural cavern space with three uranium veins and a limestone wall. Beyond the limestone wall is more uranium and another limestone wall. Through the second limestone wall is a large cavern with many uranium veins and radscorpions. Two more limestone walls flank this large cave: the wall to the east hides a family of mole rats, and the wall to the west reveals a leveled sentry bot, while both areas feature more uranium.

Inhabitants

 * Overseer Barstow
 * Security Chief Andersen
 * Julian
 * Clem (after A Model Citizen)

Notable loot

 * Vault-Tec control board - Held by Security Chief Andersen in the reactor room.
 * Three other control boards - One for each sector that can be unlocked (east, north, and northeast). They're found in each of their own sectors.
 * A Vault 88 trunk - To the right of the entrance. Contains 10 Vault 88 jumpsuits and 10 Pip-Boys, with an eleventh jumpsuit on top of the trunk. The contents of the trunk are reset as soon as the Vault is exited.
 * Legend of Vault 88 - Given by Overseer Barstow after completing all of the experiments.

Appearances
Vault 88 appears in the Fallout 4 add-on Vault-Tec Workshop.