Vault 69

Vault 69 was one of the Vaults created by Vault-Tec, and part of the Vault Experiment. Of the one thousand people who entered, there was only one man. Penny Arcade Comics gives little insight into the Vault besides that the one man was obviously uncomfortable, and the women were constantly fighting over him. It could also be discussed about and/or speculated upon that the number of the vault is a reference to the sexual position of the same name, adding to the sexual nature of the vault's purpose. Vault 68 was 69's counterpart, containing 999 men and only 1 woman. The result of Vault 68 could very well have been similar to the presumed fate of Vault 69, with the majority sex killing each other over the single minority.

Appearances in games
Vault 69 did not appear nor was mentioned in any of the Fallout games. It was mentioned in Chris Avellone's Fallout Bible, in a text which explained the Vault Experiment, therefore this Vault was either made up by Chris Avellone or came from the design document his text was based on. A concept art of Vault 69 was made by one of the Van Buren artists, which means that it was either to appear in the game, or the artist just did it for fun. It also appears in the official Fallout 3 Penny Arcade Comic.