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.
Fallout: 8 Famous Real-Life Landmarks
Since the Fallout games take place in America, you will come across some landmarks that are based on real-life locations.
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 on January 13, 2026, by Anastasia Maillot: The Fallout franchise is rearing its head again, thanks to the popularity of Amazon's TV show that takes the audience deep into the Mojave Wasteland. It has sparked talk about Fallout 5, and potential remasters for Fallout 3 and Fallout: New Vegas. It's a great time to finally revisit some of the nasties, disturbing experiments in the Fallout universe, with a brand-new addition from the TV show.
1 Vault 24
Brainwashing And Communism
- First Appearance: Fallout TV show
- Location: Mojave Wasteland
Originally, any information about Vault 24 was confined to Fallout: New Vegas. The story is that the game had a jumpsuit that could only be accessed through console commands, which hinted towards the existence of a Vault 24, at least in lore. Development-wise, there were apparently no plans to ever feature a vault like that in the game, which made it a perfect pick for the TV show to feature on the big screen, to expand the lore and serve its story.
Vault 24 in the show is a brainwashing experiment, where scientists were trying to turn Americans into communists by using propaganda videos, as well as a few more invasive methods. One of them is the infamous black box teased in season, a mind-controlling device originally created by RobCo Industries. By the time Cooper and Lucy arrive, the vault is in shambles, but it gives a pretty good idea of what Hank's plans and heading are next.
2 Vault 87
Residents Served As Test Subjects For The FEV
Fallout 3
- 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.
3 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 was 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.
4 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 victims' 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.
5 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.
War Never Changes: The 16 Best Quotes From The Fallout Games
There have been a lot of awesome quotes sprinkled throughout the Fallout series. Here's a look at 10 of the all-time best.
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.
6 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.
7 Vault 27
An Experiment In Overcrowding
- First Appearance: None
- Location: Unknown
Vault 27 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.
Fallout 4: Best Armor Sets, Ranked
Fallout 4 contains many useful armor sets that players should definitely try to find, but these are arguably the best.
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.
8 Vault 19
Psychologically Induced Tribalism
Fallout: New Vegas
- Released
- October 19, 2010
- Developer(s)
- Obsidian Entertainment
- Genre(s)
- RPG
- 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.
9 Vault 111
One Of Several Cryogenic Experiments
Fallout 4
- Released
- November 10, 2015
- Developer(s)
- Bethesda
- Platform(s)
- PC, PlayStation 4, PlayStation 5, Xbox One, Xbox Series X, Xbox Series S
- 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.
6 Ways To Become Overpowered In Fallout 3
Dominate the Capital Wasteland with these methods of becoming OP.
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.
10 Vault 12
A Vault Without A Working Door
Fallout
- 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.