Vault A vault is a type of subterranean installation initially designed by the Vault - Tec Corporation , later constructed in collaboration with RobCo Industries . Officially , they were designed for the sole purpose of sheltering up to one thousand citizens each in the event of a nuclear holocaust ; however , in reality , they were a series of secret experiments orchestrated by the United States government . Background . Commissioned by the U . S . government in 2054 as part of " Project : Safehouse , " also known as the " Societal Preservation Program , " the Vault - Tec Corporation constructed 122 vaults across the country . However , at the onset of the Great War in 2077 , most vaults were sealed without many of their intended inhabitants , a result of the “ cry wolf effect " that previous training drills had on the populace . The first vault was constructed beneath Los Angeles , and was intended to demonstrate the viability of such a facility . Unlike subsequent installations , this demonstration vault was not part of the ulterior experiments behind Project : Safehouse . By 2063 , most of the vaults had finished construction , with the exceptions of 13 , 114 , 118 and 88 . Vault 112 is the last known construction on record , completed in June of 2074 . Overview . The vaults were some of the most expensive shelters in the pre - War world . According to the Vault Dweller ' s Survival Guide for Vault 13 ( otherwise known as the Fallout manual ) , the intended budget for that particular installation was 400 billion dollars , and by the end of its construction reached $ 645 billion ( although it should be mentioned that prices in the Fallout setting are highly inflated ; in " " there are gas station signs listing regular gas at $ 1450 . 99 , and there are advertisements for vehicles in " Fallout 3 " loading screen slides for " Only $ 1 , 000 , 000 . " ) . The vaults were located in various locations , and little information is available as to why those particular sites were chosen . Each vault was designed to hold one thousand occupants at any given time , although hot - bunking was required at maximum capacity , and equipped with all facilities and supplies needed by them to survive in isolation for the designated time . According to the Vault 101 PA System , the life support system could work for over 900 years without failure , and the odds of a vault failing were 1 , 763 , 497 to 1 . In addition , the PA system also stated that the average life expectancy in a properly maintained vault is 92 . 3 years . The facilities and supplies for Vault 13 included complete construction equipment , hydro - agricultural farms , a water purification system , defensive weaponry to equip 10 people , communication systems and surface monitors , social , and entertainment files ( for total duration ) . Waste management was conducted by burning trash on scheduled " burning days . " Larger incinerator receptacles were used for the destruction of human corpses . In addition , some vaults received one or two G . E . C . K . s , intended to help the inhabitants create a viable civilization in the post - nuclear world after the All Clear signal is sent . Different types of power sources were utilized for the vaults . Vault 13 relied primarily on geothermal energy , with backup power available from a General Atomics nuclear power generator , enough to sustain the vault for two hundred years . Vault 8 on the other hand , relied on an inefficient nuclear reactor , which , while enough for Vault City to emerge , could only support a relatively small , highly advanced settlement , and in 2241 was nearing its capacity , after which further growth would be impossible . All vault dwellers wear blue - and - yellow jumpsuits , although the design varied between different vaults . Needless to say , most vaults in the experiment failed and had results completely different than those advertised . Many who exited successful vaults seem to suffer from xenophobia ( fear of strangers ) and / or agoraphobia ( fear of open places ) ; notable examples would be Michael Angelo , who doesn ' t dare leave the Strip even for inspiration , the Boomers who shoot artillery at anything that comes close to them , the Vault 101 citizens , who still don ' t exit the vault even after the Lone Wanderer opens its door , and most of the Vault 81 citizens , who are wary of outsiders after Overseer McNamara opened the vault to trade with wastelanders . Notable exceptions would be the Vault Dweller , the Lone Wanderer , Butch DeLoria , Doc Mitchell , Rylee , Susie Mack ( In the Out of the Vault random encounter ) and the Sole Survivor . Layout . The vaults are all very similar in their basic functions , but sometimes were constructed according to different designs . The vaults of the New California area differ from those constructed in the vicinity of Washington , DC , the Commonwealth , and the Mojave area . Due to scaling , the size of vaults in games shouldn ' t be taken at face value . None of the explorable vaults in the games have enough space or facilities to actually house 1000 people ( or rather 500 , as is used at maximum capacity ) . However , many doors within in - game vaults are inaccessible , which allows for the possibility that the vault is far larger than the areas the player can access . Entrance . The entrance houses the vault ' s only connection to the outside world - the airlock ( with the exception of Vault 19 , Vault 87 , Vault 88 and Vault 118 ) . It is closed from the inside by a reinforced high - security door and from the outside by a massive , gear - shaped , four - foot thick vault door , which Three Dog claims " weighs , like , thirteen tons . " For most vaults this is the only means of entering or leaving . Most vaults have consoles located on both the inside and outside , both of which require a security code to open the outer door . These codes are usually only known to a handful of people within the facility so as to prevent unauthorized exits . The automated narrator in Washington DC ' s Museum of Technology states that the vault doors had a projected 2 % failure rate in case of a direct hit by a nuclear missile . The only known vault to have been hit by a nuclear weapon is Vault 87 , and according to the logs of its overseer , that blast damaged the door beyond repair . This could have been merely a " lucky shot " falling within the 2 % failure , but it seems more likely that Vault - Tec ' s strength projections were incorrect or defined failure as allowing the inside of the vault to be damaged or irradiated . Most vaults use a Seal - N - Safe Vault door Model No . 343 to secure the airlock . Some older vaults , such as Vault 101 , use a different , cruder blast door model . Vault 8 , the control vault , had also a second , much larger , blast door built , securing the entry hallway leading to the entrance to the vault . Vault 111 and Vault 118 are the only known vaults to feature an elevator leading to an underground area where the gear shaped door is located already secure in the hill it was built in . The entrance level also houses the Emergency Medical Lab complete with an Auto - Doc . A vault medic was required to be present at the EML 24 hours a day . The lab had the equipment to treat nearly all injuries and illnesses , ranging from simple bruises to radiation . Living Quarters . Standard pre - War design of the living quarters was that of a single room with a sanitary annex . Vault 13 had one hundred living quarters , and at maximum capacity , ten people would be assigned to a single living quarter , in a hot - bunking system . A standard level had 20 , 000 square feet of usable area . The lights in the vaults used Simu - Sun technology , making it feel just like the outdoors , with only a fraction of a sunburn risk . The lights in Vault 101 were kept on all the time to prevent a radroach infestation . New Entertainertrons were used to play holotapes and used as a slide projector in the classroom of Vault 101 . Command Center . At the heart of the vault , the command center was where the overseer ' s seat was located . The operations center , apart from the seat of power , included the computer lab , where the water purification system was located , and an armory , where the vault ' s weapons , ammunition and armor was stockpiled . A security guard was posted in the command center at all times , to ensure that the armaments were properly secured and handed out only to people possessing the proper clearance from the overseer . The overseer is also able to see anyone inside the vault with the Eye - on - You cameras . Apart from that , the level also contained the computer core ( with the vault ' s AI monitoring the shelter 24 / 7 ) , housing data processing units , a library playing an important role in educating vault dwellers , a common meeting room , and the primary store room , where the most important supplies would be stored . Equipped with dual 5 . 56mm miniguns in some vaults , the overseer ' s command post can be considered the last line of defense in case vault security is breached . In the Secret Vault , there are several command posts for the various sections . The command posts mainly contain buttons to control things like locking of doors and laser protection . True purpose . Officially , the vaults were nuclear shelters designed to protect the American population from nuclear holocaust . However , with a population of almost 400 million by 2077 , the U . S . would need nearly 400 , 000 vaults the size of Vault 13 , while Vault - Tec was commissioned to build only 122 such vaults . The government , and Vault - Tec , never really believed an actual nuclear war would occur ; the " real " reason for the existence of these vaults was to run social experiments on pre - selected segments of the population to see how they react to the stresses of isolation and how successfully they recolonize Earth after the vault opens . The Enclave , responsible for the experiment ( officially known as the " Societal Preservation Program " ) , considered " themselves " prime candidates for recolonizing the world after a nuclear holocaust and to this end commissioned the construction of their own shelters , isolated from the vault network . The purpose of the vault experiments was to help prepare the Enclave for either re - colonizing Earth or colonizing another planet if Earth turned out to be uninhabitable . The total number of vaults is a government secret and has been lost ; there were the aforementioned " public " vaults , which numbered 122 and an undisclosed number of " private " vaults . Information on whether Vault - Tec was an international corporation or strictly U . S . based , cannot be released due to Vault - Tec and United States federal regulations . That said , Vault - Tec seems to have constructed some vaults in Canada . In a letter sent to a rejected DC citizen the company offered to provide a list of " Vault - Tec facilities with available accommodations , in exciting locales such as Oklahoma and newly - annexed Canada . " Of the 122 known public vaults , only 17 were control , meaning that only 17 were made to public expectations . All others were designed to include a social experiment , sometimes with a select few of the inhabitants observing the occupants . While some vaults had ' noble ' goals , such as to eradicate disease ( Vault 81 ) or improve the human genome ( Vault 75 ) , they had incredibly unethical methods of doing so , often exposing their inhabitants - often fatally - to some danger specific to certain vaults to research the effects . The few vaults that survived intact for more than 80 years came to serve another , unanticipated purpose : they were an excellent source of pure human stock , uncontaminated by the mutated airborne strain of FEV and prime candidates for conversion into super mutant s . The true nature of the vaults epitomized the insidious nature of the government at its most callous , a running theme in " Fallout " that the American government was unconcerned with the wellbeing of its people even in absolute crisis . The innumerable loss of life caused by making so few vaults , and their intended use as social experiments , and toying with what little remained of the American population highlights this . Worse , if the Enclave met setbacks , failed or were rendered incapable of recolonizing the world , it appears there was no backup plan to utilize the vaults to replenish humanity . Results . In terms of providing safety and security for their inhabitants , most of the vaults were complete failures . However , as noted in the " Penny Arcade " comic , the vaults were never truly intended to ‘ save ’ anyone ; there was simply not enough time , money or resources to build enough shelters to house more than a fraction of the population . While the “ control vaults ” did function as advertised and opened on schedule , most of the vaults were actually intended to explore and observe how societies succeeded or failed to adapt in response to various challenges and restrictions . These social experiments were conducted on live , ( largely ) unaware subjects , monitored by Vault - Tec researchers in several separate facilities , and undertaken at the behest of the future Enclave as part of a massive feasibility study of how to best resettle a devastated Earth or , if necessary , colonize another planet . Most of the vaults seen in the games were non - viable 200 or even a mere 80 years after the War . While Vault 13 " might " have lasted until its scheduled opening date of 2277 , the unplanned failure of the water chip forced the overseer ' s hand and set subsequent events in motion . If Vault 101 was truly intended to stay closed " forever , " its failure was inevitable ; the only question was how long , and what form the change or disaster would take . Many other vaults were abandoned because of unlivable conditions , or saw the residents driven violently insane by the procedures inflicted on them . Some of these continue to pose a hazard to the unwary who wander in from outside , looking for loot or a place of safety . Out of all the vaults , only the control vaults were a success , with all experimental vaults failing in one way or another . There are however exceptions ; Vault 101 while an experimental vault technically failed as it was never meant to open ; Vault 3 is another exception as technically a control vault , it failed as all the residents were massacred by the Fiends ; Vault 81 is the last exception , as its experiment was sabotaged from the start by the overseer , so it instead acted like a control vault . Despite all of this , the experiment may be considered a success in terms of the data collected - data that was much more important to the Vault - Tec and Enclave scientists than a few hundred thousand lives , most of whom would have died anyway if not for the vaults . However , it is unknown if this data was recovered / used , as there is no reference in the " Fallout " universe of the Enclave receiving / collecting the data or Vault - Tec existing in the post - war world . Behind the scenes . The vault experiment was an idea created by Tim Cain during the initial stages of " Fallout 2 " development . The developers intended for the player to first encounter information about the Vault Experiment as they read the Vault 8 records in " Fallout 2 " . They could discover a classified file ( opened with a successful Science skill roll ) explaining the purpose of Vault 8 was to be a " control Vault , " designed to hold 1000 people and open at a designated time . This file was intended to foreshadow the discovery of the true and sinister purpose of the vaults . The player was also intended to apply his Science skill to the central computer in Vault 13 to obtain a history of Vault 13 , the overseer ' s involvement in the Vault Dweller ' s expulsion , and even worse , the true purposes of the vaults . The overseer was conscious of the true purpose of the vaults as social experiments on a grand scale , and consequently drove out the Vault Dweller because of fear he would ruin the experiment . . . or uncover it . Sources . Most of the above comes from :