Fallout 4 created by Bethesda Game Studios.
Images used for educational purposes only.
Main Walkthrough

Prerequisites: Travel to the Diamond City area
Trigger: Try to open Vault 81
Reward: 100 XP

- In order to learn about Vault 81 you need to hear about it while you’re on the road. There are a few different ways to do this, but they generally boil down to a travelling NPC chatting to you about the Vault. In one case I met a Vault Dweller caught in the middle of a firefight near the Revere Satellite Array; in another, I met a vendor who said he was headed back that way to restock. Both will put Vault 81 on the map.

- Even if you don’t get Vault 81 on your map, it’s not too hard to find. Leave Diamond City and wind through the streets to Chestnut Hillock Reservoir, the nearest lake to the west. Watch out for Super Mutants while you’re still in the city, and a potent combination of Bloodbugs and Bloatflies near the Reservoir. The entrance to Vault 81 is up the western hill.

- Pop into the cave that is the entrance of Vault 81 and you’ll find a console waiting, similar to the one back in Vault 111, that’s used to open the Vault. Try to access it, though, and a voice will stop you, and another will shortly take over, belonging to the Overseer. If you’re persuasive enough you can get the Overseer to let you in just by saying that you’re a Vault Dweller; otherwise, you’ll have to go looking for three Fusion Cores before they’ll open the door. You can find Fusion Cores in the following ways:
  • Via exploration. Most indoor side areas, notably any military bases, will have at least one generator with a plugged-in Fusion Core. Examples include USAF Satellite Array Olivia and the Federal Ration Reserve. 
  • Through purchase. Most vendors will have at least one Fusion Core in their stores. The Brotherhood of Steel in particular has a lot on the Prydwen.
  • Via Power Armor units. Fusion Cores are used to power these suits, and occasionally you’ll come across a suit with a Core already plugged in.
  • In random ammo and item boxes. Maybe you’ll get lucky!

Once you have three Cores the Overseer, McNamara, will open the door and accept payment. Speaking to her will finish the quest, as well as grant you access to the Vault in general. Now you can wander around, which we’ll do now.

Vault 81

Lots to see in here. Let’s explore.
  • First thing’s first: most everything in here counts as owned. Don’t go around nabbing items unless you want to get in trouble.
  • There are two named NPCs, Neil and Miranda, by the entrance. Neil is nice; Miranda is not. As you’re walking through the entrance a cat will burst past; this is the beginning of the Here Kitty, Kitty quest.
  • Take a right down the next hall to find an elevator. At the bottom is the main living area. A kid named Austin will show up and offer a tour for five caps; if you’re even mildly persuasive you can get him to lead you around for free, and earn some experience in the bargain.
  • First up on your right is the Depot, owned by Alexis. She has complaints about her husband. You can buy odds and ends from her.
  • There’s a guy named Calvin just west of here. Calvin will pay you fifteen caps for any tools you find. Caps are so abundant in other areas, so keep him in mind for some quick money.
  • The Overseer's office is last on your right. She doesn’t have much to say, but you can hack her Advanced terminal for some info on the Vault.
  • The south side of the main floor has a small storage room. How exciting.
  • Head downstairs. You’ll find a barber shop, an eatery, and an indoor garden along the main concourse. You can steal as many Melons from the garden as you like, and there's a Taboo Tattoos sitting in the barbershop.
  • North from here is a residential section. There are a bunch of small apartments here, though virtually none of them have anything of use besides stuff you’d be stealing. Tisk.
  • There’s a classroom at the east end of the residential section, on the upper floor. The teacher, Katy, will ask you to give a talk to the kids. Agree to gain the Short Stories quest.
  • On the lower floor, just below the classroom, is a clinic. Dr. Forsythe, the resident physician, will ask for a blood donation; you can earn some extra caps if you’re feeling persuasive. His assistant, Rachel, provides normal doctoring services.
  • To the left of the classroom is a hallway leading to the Vault’s reactor. A dude named Bobby in here will buy Jet off of you for 75 caps. His sister will tell you more about his habit. Also down here is Rusty, an old Mister Handy unit.