Vault 0

Vault 0, unlike most Vaults involved in the Vault Experiment, was not an experiment in human behaviour. For that reason, Vault 0 is often considered non-canon.

Vault 0 was constructed as a storage place where the biggest geniuses of the pre-war United States could be kept in a cryogenically frozen state. They were hooked up together to one big machine called the Calculator, who was supposed to function together with those minds to build an ideal society in a post-war country by educating the survivors. Rather, the Calculator went insane and wanted to carry out mass genocide on the wasteland survivors.

Vault 0 thus becomes the end-setting of Fallout Tactics as the player character and his team have to stop the machine.