Vault 101

Vault 101 is a Vault-Tec Vault located in the Capital Wasteland, near the ruins of Washington, DC, specifically in the ruins of Springvale.

Vault Experiment
The purpose of Vault 101 in the Vault Experiment was not only to test the results of indefinite isolation, but also had a greater purpose of testing the role of the Overseer. This Vault was sealed before the bombs ever even hit, and the residents were kept in the dark as to the true nature of the aftermath, receiving fake radio transmissions which painted a far bleaker picture than even the Wasteland offered. It was the Overseer's job to keep this secret and make sure the Vault stayed sealed, and the first Overseer was actually a trained Vault-Tec official. The second Overseer (who was trained by the first) decided to let a select few of the adults in on the secret to help keep it from the children, and over the years each subsequent generation had more and more residents who knew the truth about the Vault. Also, the Overseer was able to communicate with, and even visit, the outside world by using the secret tunnel in the Overseer's office. However for all other intents and purposes, the vault's residents were sealed in, "It is here you were born, it is here you will die".

History
After the Great War, this Vault was sealed for 200 years, until one young Vault 101 Dweller (the player) discovered that the only family member he/she had - his/her father, suddenly disappeared from the Vault. The player was forced to flee and seek his or her father in the outside world for answers when the overseer's security forces were ordered to detain him for interrogation.

Upon meeting with Madison Li, the Dweller learned that Vault 101 had previously been opened prior to the start of Fallout 3, as the player had in fact been born outside the Vault; she had been present at the birth. The player's father took the infant player with him into the Vault during the short period that the Overseer permitted exploration of the wastelands. After the death of several citizens, the Vault was once again sealed and those involved swore to never reveal it had ever been opened. The fiction was then maintained that the Vault was meant to stay locked permanently to prevent the next generation from wanting to leave.

There are also reports on the Overseers computer that describe the explorations of the outside, hinting that the Vault has indeed been opened before.

Further investigation reveals more than just the father of the Vault 101 Dweller have escaped in the past. Numerous characters in Megaton recall people who have previously escaped. Moira Brown recalls a girl who escaped "10 or 12 years ago", while Colin Moriarty recalls someone escaping 5 years ago, who told him of the brainwashing that occured in the vault.

The town of Megaton was founded by people who were trying to get into this Vault, and some of the people who tried to get into the Vault still have signs and are skeletons outside of the Vault door.

Even further investigation reveals that the vault itself performed "Excavations" to scout the surrounding areas. Evidence of this is in the Overseers personal desktop.

Appearances
Vault 101 appeared in Fallout 3 as the Vault where the main character was raised by his/her father until the age of 19. The quest Trouble on the Homefront allows you to re-enter Vault 101 after leaving.

Families
Almodovar family:
 * Alphonse Almodovar - the Overseer
 * Amata Almodovar - daughter of Alphonse

DeLoria family:
 * Butch DeLoria - Leader of the Tunnel Snakes
 * Ellen DeLoria - mother to Butch

Mack family:
 * Allen Mack - father to Wally and Steve
 * Gloria Mack - mother to Wally and Steve (Stanley's daughter)
 * Wally Mack and Steve Mack, brothers
 * Susie Mack daughter of Allen and Gloria

Hannon family:
 * Paul Hannon Sr., Vault 101 security chief
 * Vikki Hannon, his wife
 * Paul Hannon Jr., his son

Gomez family:
 * Herman Gomez, Security officer, father of Freddie, and friend of James.
 * Pepper Gomez, his wife
 * Freddie Gomez, his son and member of the Tunnel Snakes

Kendall family:
 * John Kendall, Security guard, father of Christine and Monica
 * Mary Kendall, his wife (Stanley's daughter also)
 * Christine Kendall, classmate to the Lone Wanderer
 * Monica Kendall, younger sister to Christine. Never seen, only mentioned during Trouble on the Homefront

Holden family:
 * Tom Holden, vault dweller, killed by security during Escape!.
 * Mary Holden, his wife, killed immediately after him.

Palmer family:
 * Jonas Palmer, Scientist, friend to James, and son of Anne Palmer
 * Anne Palmer, Never seen. Leader of a scouting party that left the vault.
 * Lucy Palmer, mother to Anne and grandmother to Jonas.

Armstrong family:
 * Stanley Armstrong - Engineer, friend to James. Father of Gloria Mack, Mary Kendall and Beatrice Armstrong.
 * Beatrice Armstrong - Slightly odd woman, poet and tarot reader.

Taylor family:
 * Officer Taylor - Older security guard, husband to "Grandma" Taylor.
 * Grandma Taylor - his wife.
 * Chip Taylor?

Other

 * James - the Vault Dweller's father
 * Andy - a Mr. Handy type robot, reassigned (with horrific results) to doctor duties after Escape!
 * Edwin Brotch - Vault teacher and friend to the Vault Dweller.
 * Floyd Lewis - Engineer found dead in Escape!
 * Officer O'Brian - Security officer responsible for killing Tom and Mary Holden
 * Officer Richards - Security officer responsible for killing Tom and Mary Holden
 * Officer Wolfe - Security officer
 * Officer Park - Security officer
 * Officer Wilkins- hostile security officer during Trouble on the Homefront
 * Officer Armstrong- if Officer Gomez died during Escape!, he will greet you instead

Found dead during Trouble on the Homefront

 * Jim Wilkins
 * Steve Armstrong
 * Chip Taylor

Radio
Vault 101 residents broadcast their own radio station, which can be reached only inside the Vault, or when standing in the entrance.

It apparently has a stronger emergency signal, which can be broadcast outside of the vault and in the general Megaton area.

Related quests

 * Baby Steps
 * Growing Up Fast
 * Future Imperfect
 * Escape!
 * Trouble on the Homefront

Bobblehead
The Bobblehead: Medicine is in James', or more likely known as your Dad's office. You only have three chances to obtain this bobble head. When you're about to take the G.O.A.T., when you escape the vault you'll come through his office, or when you return in the "Trouble on the Homefront" quest.

Schematics
There is a schematic for the Rock-It_Launcher that can be found in the "Framed Quote" within James' Office.You need to pick the lock, which requires 50% lockpick.

Random Encounters
At higher levels, four or five Deathclaws will sometimes spawn down the hill from Vault 101. Jump up on the rocks in front of the Vault entrance and they cannot reach you. Pick them off at your leisure. Unfortunately, if Dogmeat is waiting for you there, attacking the Deathclaws will mean certain death for the canine. If this happens, sneak, tell Dogmeat to follow you and back away from the Deathclaws.

Trivia
The name of the vault might possibly be a reference to Room 101 from the novel 1984.

More likely, however, is the fact that the number stands for the most basic introduction to a subject. This comes from the United States, where colleges number courses starting at number 101. As the player learns the basics of the game in their own vault, it is likely that this is the reason for the number of the vault.

Andy the robot had taken over as the vault's doctor, although after his last "surgery" it seems he has been fired. He amputated a woman's whole leg because she had sprained her left big toe. But if you look at the body you will see that he actually amputated the right leg on accident.