Fallout: Ranking Every Vault From Least To Most Horrifying
24. Vault 13 - Stays Closed For 200 Years To Study Prolonged Isolation
Appearing in both Fallout 1 and Fallout 2, on the surface Vault 13 doesn't sound too bad. There's no particular horrible social experiment at work here, and the Vault had plenty of resources and even a GECK supplied to them.
Originally this Vault was part of an experiment called the Societal Preservation Program, intended to keep the Vault sealed until the people inside were needed by The Enclave. The Fallout Bible, however, reveals that the Vault was also designed to remain closed for 200 years to study how prolonged isolation affected its inhabitants.
Vault 13 also has the distinction of being home to the Vault Dweller, original Fallout protagonist. He is sent out to the wasteland from the Vault after a malfunctioning water chip meant the Vault must be opened.