Vault 106

Vault 106 is a Vault-Tec Vault located in the Capital Wasteland. It is located within a large cavern southeast of Arefu, directly south of Kaelyn's Bed & Breakfast, and a bit north of Jury Street Metro station.

Background
As part of the Vault Experiment, psychoactive drugs were released into the Vault 106 air filtration system 10 days after the door was sealed. Information in the Vault's computer terminals reveals that the overseer knew that the inhabitants of his Vault would be fodder for drug testing and he instructed his security personnel to tell those in the Vault that everything was fine.

By 2277, the Vault's interior is mostly destroyed and filled with insane survivors. The psychoactive drugs are still being pumped through the Vault's air filtration systems, as evidenced by the player character's vision suddenly being shaded blue at the same time that hallucinations appear. At the very end of the Vault is a cave-like area, where skeletons and other items are located, including a Mini Nuke.

Enemies

 * Several insane survivors inhabit Vault 106. They wear Vault 106 jumpsuits and wield a variety of melee weapons, such as lead pipes, knives, baseball bats, pool cues, Chinese officer's swords, sledgehammers (at high levels), etc., Despite not wearing armor, the insane survivors are slightly tougher than the average raider.
 * A "survivor" (who has the same ambient/combat voice files as a Raider) is on the lowest level, at the end of the science lab section, wearing a Vault lab uniform and wielding a baseball bat. When first encountered, the survivor will activate a Stealth Boy that will remain active until the survivor is killed. The player character then has a hallucination in which the Tunnel Snakes (Butch DeLoria, Wally Mack, and Paul Hannon) attempt to kill them. After the survivor sustains some damage, the Tunnel Snakes will use Stealth Boys and flee, and the player character will see as if in a hallucination (with the purple tint). This will end after killing the survivor. If the Tunnel Snakes are killed by the Lone Wanderer or if they use the Mesmetron on them in the hallucination, they just disappear without leaving a body behind. Both killing them and them fleeing ends the hallucination.

Entrance

 * The torn out journal entry can be found under a large ruined book on a table (with another large ruined book and a chemistry set) in one of the side rooms. Coming from the Vault door down the stairs to the right, first hallway one encounters, then the first room on the right.

Living quarters

 * A copy of Nikola Tesla and You is inside the classroom in the living quarters. After first entering the top level of the living quarters (it's a two level hall), cross the short catwalk, and enter the door on the lefthand side of the hall. The book is hidden, together with two tin cans, in the bottom wooden box of those stacked (with a drinking glass at their top) on the teacher's desk.
 * The Science bobblehead is located left diagonally across from where the player character first enters. Cross the short catwalk on the left, turn right to a hallway next to the classroom. Open the door, turn right, open the second door, and follow the corridor to a room. The bobblehead is on a bookshelf against the back wall (third shelf).
 * A poem entitled "Scribbles" is found on a table with a monitor on it, near the entrance to the overseer's office.
 * Feel the love man - A note, downstairs in the leftmost room of the male dorms. It appears to have been written by one of the insane Vault residents.
 * To anyone who gets this - Another note, on the ground in front of the locked (average) door south in the local map. It is written by a non-insane Vault resident.

Science lab
(Note: There are two entrances to the science lab, and the notes below pertain to only one, for directions.)
 * A copy of Tumblers Today is on the science lab level. From the entrance, head straight down the corridor (passing an open doorway) and take the stairs to the right. It's the first door on the right after the stairs, in the large room with all the machines. Turn left and then immediately left again after entering and head to the back of the room - the book is on top of an overturned machine, near to the window (two bottles of milk are also on top).

If one enters from the living quarters/overseer's office into a large room with large machines, follow the right-hand wall (turning right twice) until coming to a door. Go through the door, keep following the right-hand wall — a left, quick right, right, right, down the stairs, left, right — until coming to a door. Go through the door, turn left and then immediately left again after entering and head to the back of the room - the book is on top of an overturned machine, near to the window (two bottles of milk are also on top).
 * A Mini Nuke is in the final room of the science lab area, just past the fight with the Vault 106 survivor.
 * There are two Vault 106 master keys (which can open the door to the overseer's office).
 * One can be found next to a functional computer terminal in the northwest corner of a room in the living quarters that is only accessible through the science labs. (The player character can see the room and the science lab's door through barred windows in the living quarters, but they have to go upstairs, through a door in a room with a reactor in the labs to get to it.)
 * There is another one at the bottom of a shelf in the storeroom, behind the one where you fight the Vault 106 survivor. Note: this "key" is actually a red passcard. Although it looks normal, one cannot see the message when hovering the mouse pointer over it, and thus cannot pick it up. It is probably a bug. The player may use the "tcl" command and go closer to reach the key.

Appearances
Vault 106 appears only in Fallout 3.

Behind the scenes

 * Several additional hallucinations were planned and partially implemented for Vault 106, including a room appearing upside-down for a short time, a hallway where the Lone Wanderer would gradually shrink as they progressed along with it, hallways appearing where blank walls had been before, and the "boss" survivor initially appearing identical to the Lone Wanderer's father.
 * In addition to the unused hallucinations, a special helmet called the makeshift Gas Mask was placed in two locations within Vault 106. Wearing the mask would have prevented any further hallucinations from happening. The mask was mostly implemented but suffered from a scripting flaw that permanently re-applied the blue tint whenever it was removed, even outside of Vault 106.

Bugs

 * The hallucinations of the player character's Dad that appear throughout Vault 106 are always the default Caucasian model, even if one chooses a different race for their player character (and thus also for their father).
 * The game sometimes defaults the player character's body (though not the head) model to the default Caucasian model, staying that way until one reloads the game.
 * At higher levels when attacking the Vault 106 survivor, even though the survivor might be dead, the Tunnel Snakes will literally "float" into the room without the blue hallucination backdrop. Killing them grants experience points.
 * If the player character shoot at Amata she will disappear, but if they kill her with one shot, they will receive negative Karma and her clones will turn hostile towards them but, upon reaching them, they will just stand next to the player character, giving them an angry look with their fists up.
 * Despite the insane survivor's natural hostility toward the player character, dropping a live grenade on them grants bad Karma.
 * Some hallucinations that are targeted in V.A.T.S. will cause the game to crash if they disappear while V.A.T.S is zooming in or the player character is taking out their weapon.
 * If one shuts the main Vault door (the round one) it will appear as if it is not shut all of the way. Another way to see this is to leave the door open and you will see that it is, in fact, pulled farther back than the rest of the Vault doors in the Capital Wasteland.
 * After having killed the "survivor," if the player character attacks their corpse the blue hallucination tint will appear.
 * Sometimes after killing the survivor, their eyes will blink even though they are dead.
 * If the player character goes into the overseer's office and jumps near the wall to the right, near the terminal station, they will fall out of the map. One way to get back is to step into the void, and one will teleport back into the hallway before the office.
 * The other is to land on the overseer's tunnel as soon as one jumps through the wall, face their office and move all the way to the right, and then jump out through the small gap in the map to land on a tunnel below (some health will be lost). From there, turn right and ascend the top of the stairs that are the furthest away, forward, from the player character. After one has reached the top of the stairs, continue heading forward until reaching an opened door, directly east of the door to the Vault entrance. If player character has not yet encountered this hallucination event, they will be teleported into the hall if they close the door and walk over it.
 * Sometimes the game will malfunction, causing the hallucination of Paul Hannon to become real. One can kill him and get a mint condition Tunnel Snake outfit off of his body.
 * When entering the room in the living quarters with the master key and the security terminal, companions may be placed on the opposite side of the wall in an area that should be inaccessible from this room.