Highlights

• Vaults in Fallout series were not just shelters, but sites of cruel experiments on unsuspecting inhabitants by Vault-Tec scientists.
• Residents of Vault 87 were subjected to FEV, transforming them into Super Mutants, highlighting the extreme nature of these experiments.
• Vault 101's totalitarian rule and Vault 11's cyclical human sacrifice show the depths of cruelty in Vault-Tec's post-apocalyptic experiments.

Although Fallout's iconic vaults were billed to the public as impenetrable bastions meant to preserve the basis of American society in the face of nuclear fire, the reality of the situation was a little more complicated than that. Vaults were certainly more than capable of protecting and providing for their inhabitants after the bombs fell, but that purpose was practically secondary to their more nefarious ends.

The majority of the vaults found throughout the Fallout series were used to perform social and scientific experiments on the populations taking refuge within. Some of these studies were relatively tame, if not altruistic in nature. Others, however, ranged from incredibly bizarre to outright cruel. To outline the lengths that Vault-Tec went to in producing these experiments, here are the cruelest and most disturbing experiments that Vault-Tec ever cooked up for Project Safehouse.

Updated April 20, 2024 by Gregory Louis Gomez: When it comes to Vault-Tec in the Fallout universe, there is no end to their depravity. Though many of the infamous vaults did keep their occupants safe from the Great War of 2077, even this was simply part of a larger, more bizarre plan for the post-apocalypse.

Most vaults were designed to run horrendous experiments on their occupants in secret on behalf of the U.S. government, resulting in incalculable suffering. Virtually every Fallout title features the vaults and their heinous experiments to some degree. With this in mind, we've added a few more entries to the list of Vault-Tec's most disturbing post-war experiments.

1 Vault 87

Residents Served As Test Subjects For The FEV

• First Appearance: Fallout 3
• Location: Virginia

Vault 87 served as a research facility for forced evolutionary viruses, with all of its residents being used as test subjects. After being exposed to one particularly nasty virus upon their arrival, they were then monitored by scientists who had been tasked with observing and recording all of the subsequent changes that came about as a result of the testing. The results were — to put it bluntly — terrifying.

Within two weeks of their exposure, many of the vault's inhabitants were dead. They were arguably the lucky ones, however, as those who did survive were transformed into the Super Mutants and Centaurs that players would later encounter while exploring the Capital Wasteland. As shocking as these experiments were though, they are just the tip of the iceberg.

2 Vault 29

Children Separated From Their Families

• First Appearance: None (Was Set To Appear In Van Buren)
• Location: West Coast

The canceled Fallout 3 from Interplay, code named Van Buren, was set to feature a host of vaults all of its own, one of which being Vault 29. Though much of the information on this vault comes from the Fallout Bible, it has officially been referenced in canon, most notably in Fallout 76.

The primary experiment here was that only children under 15 were to be accepted, with their parents going into different vaults, effectively breaking up their families forever. Not much is known about the success of this experiment, though the inhumanity of dividing up families for scientific gain should be obvious to most.

3 Vault 4

A Society Controlled By Unethical Scientists

• First Appearance: Fallout TV Show
• Location: California

Vault-Tec and its vaults are a big focus in Amazon's Fallout show. One of the vaults featured in episode 6 is Vault 4, which, from the outset, is seemingly filled with compassionate people. Later on, it is revealed that the vault took in many survivors from the destruction of the NCR capital city, Shady Sands. Underneath all of this altruism, however, is the legacy of unregulated scientific experimentation by its original inhabitants.

Among the myriad of horrific genetic experiments that their victim's descendants still pay for, many people were kept in cryogenic stasis for centuries, while mothers were forcibly (and fatally) impregnated with mutated abominations. Thankfully, the vault's first victims were eventually able to rebel against their torturers. By the time of the show, vault 4 is a haven for the victims of Vault-Tec's many crimes against humanity.

4 Vault 112

Humans Frozen In Time As Playthings For A Madman

• First Appearance: Fallout 3
• Location: Virginia

Another of Fallout 3's vaults, Vault 112 sounds like something straight out of The Matrix. Residents were placed in a state of suspended animation and hooked up to a special virtual reality simulator. Where it differs from the iconic sci-fi series is that test subjects were fully aware of the simulation. Had they known all the details though, they probably wouldn't have gone along with it willingly.

Subjects were originally told that the simulation would provide them with a perfect life, but it ended up being more like a VR horror game instead. This is because the vault's Overseer, Dr. Stanislaus Braun, physically and psychologically tortured the residents using the technology; even getting the Lone Wanderer to help him do so at one point. Shockingly, Braun had previously been one of humanity's greatest minds, but, as the old saying goes: absolute power corrupts absolutely.

5 Vault 101

Indefinite Totalitarian Rule

• First Appearance: Fallout 3
• Location: Virginia

Vault 101 was perhaps the first vault that most Fallout players experienced back in 2008. Yes, there were games (and therefore other vaults) before Fallout 3. However, the series didn't truly explode in popularity until this point. From the get-go, vault 101 seems like a quiet and safe place to live, if a little quirky at times. Over time, however, it becomes apparent that the vault's totalitarian style leadership structure is more problematic than suspected.

This was the primary experiment of the vault; to test the long-term effects of an all-powerful overseer on its inhabitants, and "long-term" meant "forever." As it turns out, Vault 101 was never supposed to open for any reason or at any time. This is partly so that the vault's residents can serve as a control group for the Enclave in its experiments as well.

6 Vault 27

An Experiment In Overcrowding

• First Appearance: None
• Location: Unknown

Vault 27 currently has yet to appear in a Fallout title. It is, however, mentioned in Chris Avellone's Fallout Bible, a collection of documents providing a wealth of information on the Fallout universe. Although these documents are no longer reliable as "official" Fallout canon, they still provide a lot of interesting information and insight into the Fallout world.

The experiment attached to Vault 27 is a relatively straightforward one; it was purposefully overcrowded by two times its maximum capacity. It isn't difficult to imagine the immediate impact of such drastic overpopulation, but, suffice it to say the specifics of the results are uncomfortable to visualize.

7 Vault 19

Psychologically Induced Tribalism

• First Appearance: Fallout New Vegas
• Location: Nevada

This vault can be explored during the events of Fallout: New Vegas, where it has since been taken over by the Powder Gangers. But, long before they arrived, its original purpose was to test the impact of subliminal messaging on its inhabitants.

Upon arrival, the residents were segregated into two groups and assigned one of two colors: blue, or red. Afterward, the vault exposed them to various stimuli that were intended to provoke feelings of paranoia and distrust. Terminal entries within the vault indicated that these subliminal messages were very effective and that the mutual distrust between its divided population was rapidly approaching a violent climax.

8 Vault 111

One Of Several Cryogenic Experiments

• First Appearance: Fallout 4
• Location: Massachusetts

Fallout 4 really begins in Vault 111, located just outside of Boston near the suburb of Sanctuary Hills. While the Vault-Tec scientists claim that the newly arrived occupants are due for a decontamination procedure, that is just a lie to make enacting the real plan go more smoothly.

In reality, Vault 111's experiment was with suspended animation via cryo-freezing, specifically to see how the human body would react to long-term cryo-stasis. The result ended up being the death of nearly every occupant for one, mostly having to do with systems failing over time.

9 Vault 12

A Vault Without A Working Door

• First Appearance: Fallout
• Location: California

In what is perhaps Vault-Tec's most straightforwardly dishonest experiment, Vault 12 was designed with a purposefully faulty vault door that would not seal properly, allowing radiation to seep into it so that its impact on the human body could be studied.

This would naturally result in the majority of the vault's population becoming ghouls. They would eventually emerge to find the ghoul haven of Necropolis, which the Vault Dweller can explore throughout the original Fallout title.

10 Vault 75

Using Children To Create The Master Race

• First Appearance: Fallout 4
• Location: Massachusetts

The experiment attached to Vault 75 is a solid contender for the absolute cruelest experiment ever carried out by Vault-Tec. Situated beneath Malden Middle School in the Commonwealth of Fallout 4, its stated purpose was to protect the school's students and their families in the event of a nuclear attack.

Upon entry, the students' parents were separated from their children and were summarily executed by the security staff under the pretense that they were undergoing "orientation." The children were then subjected to rigorous physical and mental conditioning. Those that did not achieve satisfactory results were disposed of once they reached the age of eighteen, and those that did were "harvested" for their superior genes.

11 Vault 22

Plant Experimentation Gone Horribly Wrong

• First Appearance: Fallout New Vegas
• Location: Nevada

The experimentation carried out in Vault 22 wasn't necessarily disturbing at its core. It was designed to sustain life purely by way of "green" living, keeping its inhabitants alive by virtue of the plant life that was grown and cared for within. The results, however, are where things start to get dark.

A certain specialized fungus was used to keep pests from ruining their crops. Unbeknownst to them, however, were the mutagenic properties of the fungus. Once the spores took root in human hosts, they would gradually transform them into spore carriers, deadly and aggressively cannibalistic mutants that have claimed many lives since.

12 Vault 13

The Original Control Group Vault

• First Appearance: Fallout
• Location: California

Not every vault created by Vault-Tec had a specific experiment attached to it, however, even this isn't something to celebrate. Some vaults, such as Vault 13, were primarily designed to serve as more or less an emergency stockpile of pure humans, or humans without damaged or mutated DNA from the wasteland.

These humans were to be called upon by the remnants of the U.S. government, or the Enclave as most know them, to serve as their lab rats and slaves with which they would rebuild the world. During the events of Fallout 2, the Enclave would kidnap every Vault 13 resident (or rather, everyone that they hadn't already murdered) and imprison them aboard their headquarters off the coast of California, the Poseidon Oil Rig.

13 Vault 34

A Vault With More Guns Than People

• First Appearance: Fallout New Vegas
• Location: Nevada

This vault is perhaps most famously remembered as the ancestral home of the Boomers faction in Fallout: New Vegas, where they resided before establishing their community at the Nellis Air Force base. It turns out that their affinity for weaponry has some deep and disturbing roots there.

Vault 34 was purposefully designed with cramped living conditions as well as an absurdly overstocked armory full of weapons and ammunition. The cramped vault would soon become overpopulated, and the residents would continuously request access to the armory to protect themselves, which the Overseer would deny. This would eventually result in violent rioting.

14 Vault 77

When Man's Only Company Is A Box Of Puppets

• First Appearance: None
• Location: Unknown

While it was never featured in a game, Vault 77 is mentioned in Fallout 3 and is featured in a promotional comic for the game. The main experiment of this vault was to test how a human would react in prolonged isolation with nothing but a collection of puppets.

This individual, known as the "Puppet Man," was the sole occupant of vault 77 before exiting in 2079. Interestingly, the player can find his jumpsuit in Fallout 3, as well as a holotape that implies that the Puppet Man went on to become a frightening legend among the raiders of the wasteland.

15 Vault 106

Psychoactive Drugs Contaminating The Air

• First Appearance: Fallout 3
• Location: Virginia

Vault 106 was designed to simply begin pumping psychoactive drugs into its air filtration system a mere ten days after the door had sealed itself shut. Perfectly aware of the vault's purpose, the Overseer directed security personnel to dismiss any complaints resulting from this.

The Lone Wanderer can explore this vault during Fallout 3, and will quickly come to realize that these drugs are still being filtered into the vault when they begin experiencing vivid and violent hallucinations. The few survivors left inside have been driven insane by consistent exposure to them and will attack anyone on sight.

16 Vault 81

Secret Testing Of Deadly Diseases On The Populace

• First Appearance: Fallout 4
• Location: Massachusetts

The conclusion of Vault 81's experimentation is a true rarity, as the Overseer realized the inhumanity of its purpose and put an end to it before any lasting harm came to its general population. In fact, the Sole Survivor can explore Vault 81 in Fallout 4, meeting its population of relatively sane and decent inhabitants.

Originally, the vault's purpose was to expose the population to an array of deadly diseases and illnesses, while a science team operated from a secret locale to develop and test various cures on the subjects without their knowledge.

17 Vault 108

A Vault With More Than One Inhumane Experiment

• First Appearance: Fallout 3
• Location: Maryland

One of Fallout 3's most memorably creepy locations is Vault 108. The vault had several experiments in place at the same time. Most of the standard job positions were intentionally unfilled, there was no entertainment yet an excess in weaponry, and to top it off, the life support systems were designed to fail within twenty years.

The most notable thing about this vault, however, is its cloning experiment, which resulted in a man named Gary being cloned countless times by the vault's scientists. By the time of the player's arrival, only the hostile Gary clones remain.

18 Vault 95

Tempting Addicts With All The Drugs They'd Ever Want

• First Appearance: Fallout 4
• Location: Massachusetts

Vault 95's stated mission almost seems altruistic in nature. It was to serve as a rehabilitation clinic for chem addicts, allowing them to overcome their various addictions, even as the outside world collapsed under a volley of nuclear missiles. However, its true purpose was much less than kind.

Although its detox program was a great success, a massive stash of chems and alcohol was hidden inside the vault, and a planted resident would "unearth" this cache after five years. Predictably, the staged discovery of this cache precipitated the vault's program unraveling entirely, and its population plunged into chem-fueled anarchy.

19 Vault 92

Psychopathic Suggestions Via White Noise

• First Appearance: Fallout 3
• Location: Maryland

Though it sounds like the ideal place for music lovers and artists of all kinds, Vault 92 is anything but. By the time the player comes across it, vault 92 is reduced to a decrepit ruin filled with Bloatflies and Mirelurks, however, it was once home to some of the brightest musical minds the old world had to offer. The pitch at face value was to preserve humanity's musical genius, but its real purpose was to test the effects of combat suggestions via white noise.

The vault's occupants were unknowingly subjected to white noise broadcasts through the vault's loudspeakers, eventually driving most of them insane with rage and leading to the death of virtually half of the vault's population.

20 Vault 11

Cyclical Human Sacrifice With An Ironic Twist

• First Appearance: Fallout New Vegas
• Location: Nevada

Of all the cruel experiments that Vault-Tec executed on unsuspecting victims, the one taking place at Vault 11 has to be the worst. Vault 11's inhabitants were instructed to select one of their own as a human sacrifice each year. If they refused, they were told that the vault would shut off its life support systems, and the entire population would die.

In reality, should the vault's residents refuse to sacrifice someone, the vault would provide an automated message congratulating them as "a shining example of humanity." By the time they couldn't bear to sacrifice anyone else and bravely refused, its population had been whittled down to a mere five people. Unable to cope with their guilt after this brutal realization, four of those five people elected to commit suicide.