Vault 3: A control vault designed to open after 20 years, but kept closed longer due to the wishes of the vault inhabitants. However, an unplanned water leak forced the occupants to open in hopes of trading with the outside. Unfortunately, all of the vault's residents were massacred by a group of raiders known as the Fiends shortly after they opened the vault door.
Vault 6: The vault's original purpose in the Vault Experiment was that it allowed small doses of radiation to leak into the vault once a day, resulting in the population turning into an aggressive pack of extremely irradiated feral ghouls.
Vault 8: A control vault, intended to open and recolonize the surface after 10 years and is equipped with a GECK. Vault City is the result.
Vault 11: This vault was a social experiment testing human nature - most specifically the ability to sacrifice oneself for others, and the ability to place ideals above one's own life.
Vault 12: In order to study the effects of radiation on the selected population, the vault door was designed not to close properly. This is the Necropolis vault and a large population of ghouls was the result.
Vault 13: Intended to stay closed for 200 years as a study of prolonged isolation, the broken water chip forced the Overseer to improvise and use the Vault Dweller as a pawn. Later study of the Vault 13 records by the Enclave led them to their current plan to end the war.
Vault 15: Intended to stay closed for 50 years and include people of radically diverse ideologies.
Vault 17: The vault was raided in 2154 and its inhabitants taken prisoner by the Master's Army. They were subsequently turned into super mutants.
Vault 19: The vault was segregated into two groups, Red and Blue. The groups lived in separate sections of the vault and the inhabitants may have been chosen due to pre-existing paranoia.
Vault 21: This vault's purpose was gambling, reinforced by having only compulsive gamblers admitted as vault residents, and with all conflicts within the vault to be resolved through gambling. It is one of the few non-control vaults that didn't end in failure.
Vault 22: Apparently a vault designed to develop advanced agricultural technologies. Successful experiments were executed, creating strains of plants that could grow under artificial light. However, an experiment on pest control involving a genetically-manufactured spore annihilated or transformed the vault's inhabitants.
Vault 27: This vault would be overcrowded deliberately. 2000 people would be assigned to enter, double the total sustainable amount.
Vault 29: No one in this vault was over the age of 15 when they entered. Parents were intentionally redirected to other vaults.
Vault 34: The armory was overstocked with weapons and ammunition and not provided with a lock.
Vault 36: The food extruders were designed to produce only a thin, watery gruel.
Vault 39: The original purpose of Vault 39 is unknown, but due to Mile Reese experimenting with the G.E.C.K., it became a jungle with hostile plant life, similar to Vault 22.
Vault 42: No light bulbs of more than 40 watts were provided.
Vault 43: Populated by twenty men, ten women, and one panther.
Vault 53: Most of the equipment was designed to break down every few months. While repairable, the breakdowns were intended to stress the inhabitants unduly.
Vault 55: All entertainment tapes were removed.
Vault 56: All entertainment tapes were removed except those of one particularly bad comic actor. Sociologists predicted failure before Vault 55.
Vault 68: Of the one thousand people who entered, there was only one woman.
Vault 69: Of the one thousand people who entered, there was only one man.
Vault 70: All jumpsuit extruders fail after 6 months. Most of the inhabitants were Mormons.
Vault 76: This vault was designed as a control group for the vault experiment. Like Vault 8, it was intended to open and re-colonize the surface after 20 years.
Vault 77: Populated by one man and a crate full of puppets.
Vault 87: A Forced Evolutionary Virus research and testing facility
Vault 92: Populated largely by renowned musicians, this vault was a test bed for a white noise-based system for implanting combat-oriented posthypnotic suggestions.
Vault 101: Evaluation of performance of an omnipotent, dictatorial overseer in a closed community. This vault was intended to never open.
Vault 106: Psychoactive drugs were released into the air filtration system 10 days after the door was sealed.
Vault 108: The vault houses a cloning lab and all (surviving) residents are clones of one man called Gary.