The main story of New Vegas takes place in the year 2281, four years after the events of Fallout 3 and 204 years after the bombs fell. It is set in a world that deviated onto an alternate timeline thanks to Atomic Age technology, which eventually led to a global nuclear apocalypse in the year 2077 in an event referred to as 'The Great War', caused by a major conflict between the U.S.
A spin-off of the Fallout series, the game is set in a post-apocalyptic open world environment that encompasses a region consisting of Arizona, California, and Nevada. It was announced in April 2009 and released for Microsoft Windows, PlayStation 3, and Xbox 360 on October 19, 2010. Fallout: New Vegas is a 2010 post-apocalyptic action role-playing video game developed by Obsidian Entertainment and published by Bethesda Softworks.