The Vaults: Every Major Fallout Vault and Its Secret Experiment

The Vaults are the huge underground fallout shelters Vault-Tec built across America before the Great War. They were sold to the public as the way to survive a nuclear war and rebuild afterwards, but most of them were secretly experiments on the people sealed inside. Most Fallout heroes start life in one, and the TV series begins inside Vault 33. (Fallout; Fallout 2; Fallout, "The End")

What the Vaults were really for#

The answer comes from the man at the top. In Fallout 2, Enclave president Dick Richardson tells the Chosen One that the Vaults were never built to save the population. They were a huge pre-war experiment, each one set up to see how its group of people would cope with a particular situation, with the results feeding back to the government. (Fallout 2)

The TV series tells it from Vault-Tec's side. At the summit in "The Beginning," Barb Howard settles an argument among the corporate guests by offering each company its own Vaults to experiment on, out of more than a hundred across the country. In "The Other Player," a Vault-Tec engineer tells her the company's water chips fail 30 percent of the time, and that the failures can be used to decide which Vaults run dry. (Fallout, "The Beginning"; Fallout, "The Other Player")

That's the origin story of the very first game. Vault 13's water chip breaks and the Vault Dweller of the first game is sent into the wasteland to find a replacement. (Fallout)

Life inside a Vault#

Every Vault follows the same template. Residents wear numbered blue jumpsuits, carry a Pip-Boy, and answer to an overseer. Most have a hydroponic farm, a water purifier, a reactor and a big gear-shaped door. Dwellers are told the surface is deadly and wait for the day it's safe to go back up. Fallout 76 calls that day Reclamation Day, and so does Vault 33. (Fallout 3; Fallout 76; Fallout, "The End")

Some Vaults also got a G.E.C.K., the Garden of Eden Creation Kit, to help start a new settlement once the doors opened. In Fallout 2 the Chosen One's whole quest is to find one for Arroyo, the village founded by the Vault Dweller's followers. (Fallout 2)

The most infamous Vaults in the games#

• Vault 12, Bakersfield. It never sealed properly, and its dwellers became the ghouls of Necropolis. (Fallout)
• Vault 15, California. Its dwellers left to found Shady Sands, the town that became the capital of the New California Republic. (Fallout)
• Vault 8, California. A control Vault that opened on schedule and became the wealthy, walled Vault City. (Fallout 2)
• Vault 13, California. The Vault Dweller's home. Generations later the Enclave raids it and takes its people to test their plague on. (Fallout; Fallout 2)
• Vault 101, Washington, D.C. Its overseers keep everyone inside forever: "No one ever enters, and no one ever leaves." (Fallout 3)
• Vault 87. Used for experiments with the Forced Evolutionary Virus, and the source of Fallout 3's Capital Wasteland super mutants. (Fallout 3)
• Vault 106. Psychoactive drugs were pumped into the air ten days after it sealed. (Fallout 3)
• Vault 108. Stocked with cloning gear and one man's DNA, it's now full of clones who all answer to "Gary." (Fallout 3)
• Vault 112. Its dwellers are plugged into Tranquility Lane, a 1950s simulation run by Dr. Stanislaus Braun, who tortures them for fun. (Fallout 3)
• Vault 11, Mojave. The Vault computer told the dwellers to sacrifice one person a year or all would die. When the last survivors refused, it congratulated them. (Fallout: New Vegas)
• Vault 21, Las Vegas. Every dispute was settled by gambling. Mr. House later turned it into a hotel on the Strip. (Fallout: New Vegas)
• Vault 22, Mojave. A science Vault destroyed by its own experimental fungus, which took over its scientists. (Fallout: New Vegas)
• Vault 111, Massachusetts. Its residents were told they'd be decontaminated and were frozen instead. The Sole Survivor wakes up 210 years later. (Fallout 4)
• Vault 81, Massachusetts. Hidden scientists were meant to test diseases on the dwellers. Its first overseer refused to go along with it. (Fallout 4)
• Vault 75, Massachusetts. Built under a school. The adults were executed on arrival, and the children were raised and trained, with the best of them "harvested" for their genes at eighteen. (Fallout 4)
• Vault 76, Appalachia. A control Vault of carefully chosen dwellers, opened 25 years after the war to rebuild. Its overseer also had secret orders to secure the region's nuclear silos. (Fallout 76)

Vaults 31, 32 and 33 in the TV series#

Lucy MacLean grows up in Vault 33 in Los Angeles, one of three Vaults linked by tunnels. The three trade goods and spouses every few years, and season 1 opens with Lucy marrying a man from Vault 32 in exactly that exchange. The bridegroom's party turns out to be surface raiders led by Lee Moldaver, who kidnap her father, overseer Hank MacLean. (Fallout, "The End")

Vault 32 had already died. Lucy's brother Norm and his friend Chet find it full of blood and graffiti reading "Death to management." Its people had found out something, killed their overseer and torn themselves apart. (Fallout, "The Ghouls")

Vault 31 is the secret. Dwellers in 32 and 33 believe it's just a better-equipped neighbour that always seems to produce good overseers. In "The Beginning" Norm gets inside and finds the truth: Vault 31 is full of cryogenic pods holding Vault-Tec junior executives, run by Bud Askins, whose brain now sits in a small robot. Every few decades one is thawed and placed in 32 or 33 to become its overseer and breed a line of loyal "super managers," ready for the day Vault-Tec reclaims the surface. Hank was one of them. (Fallout, "The Radio"; Fallout, "The Beginning")

Season 2 breaks the system open. Trapped inside with Bud's robot taunting him, Norm thaws the frozen executives instead of going into a pod himself. In "The Golden Rule" he persuades them that escaping is a test set by Bud Askins and leads them up a maintenance hatch to the surface. (Fallout, "The Innovator"; Fallout, "The Golden Rule")

Vault 4, the scientists' Vault#

The other Vault the show visits is Vault 4. A pre-war commercial filmed by Cooper Howard sells it as a Vault run entirely by scientists. By 2296 it holds mutated "test subjects" and a population of refugees, many of them from the ruins of Shady Sands, who seem friendly but have plenty to hide. (Fallout, "The Trap")

For the company behind all this, see Vault-Tec, and for how the Vault 33 story plays out, see the TV series explained.