Numerous easter eggs and references to various books, movies and other games are one of the staples of the Wolfenstein series. These are instances where something or someone from another game or the real world is referenced in the game itself, e.g. Wolfenstein: The New Order, in the Hanger there are two circular doors with the numbers 101 on them that look similar to Vault doors from the Fallout game series. This is a reference to Fallout 3.