Fallout: A Post Nuclear Role Playing Game is an open-world turn-based role-playing video game developed and published by Interplay Productions in 1997. The game has a post-apocalyptic and retro-futuristic setting, in the aftermath of a global nuclear war in an alternate history timeline mid-22nd century. The protagonist of Fallout is an inhabitant of a Vault, long-term shelters, who is tasked to find a replacement Water Chip and save their Vault.

Fallout is considered to be the spiritual successor to the 1988 role-playing video game Wasteland. It was initially intended to use Steve Jackson Games' system GURPS, but Interplay eventually used an internally developed system SPECIAL. The game was critically acclaimed and a financial success. It was followed by a number of sequels and spin-off games, the Fallout series.