Fallout is purely fictional. It was designed by developers to offer a unique and immersive gaming experience set in a dystopian future. There's no real-life basis for the entire Fallout universe.
No. Fallout 4 is a post - apocalyptic role - playing game set in a fictional world. While it may draw inspiration from real - world events like the Cold War fears of nuclear war, it is not based on a true story in the sense that the events and characters in the game are not real historical accounts.