The vaults in the Fallout franchise are known for their morally dubious social experiments, ranging from the slightly problematic to the wholly unethical. These were planned and implemented by none other than Vault-Tec, which had partnered with the government to conduct trials on unknowing vault residents.
Of course, every experiment requires a control element. This is precisely what the control vaults were for in the world of Fallout, and it only shows just how little Vault-Tec cared about the greater population.
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In scientific experimentation, the control element serves as a point of comparison to the elements being experimented on. In the case of the vaults in Fallout, many of them had some sort of experiment going on within. Thus, Vault-Tec set up multiple control vaults — all of which had no implemented experiment — that it could use to draw conclusions about what occurred in Vault-Tec’s experiment vaults in Fallout. In short, control vaults worked just as Vault-Tec had advertised to the public — with sufficient life support systems, ample resources, and no social experiment.
Understanding the control vaults in this way casts a shadow over Vault-Tec and its motivations in Fallout. The very existence of functional, life-supporting vaults might lead some to think that, despite Vault-Tec’s countless experiment vaults, it still intended to protect humanity from an apocalyptic situation. However, this isn’t the case.
Control vaults were nothing more than another part of the organization’s sick experiments. In other words, Vault-Tec didn’t build control vaults because it sought to save a small portion of humanity, but because such vaults were required to validate the conclusions drawn
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