Fallout: New Vegas is a post-apocalyptic action role-playing video game developed by Obsidian Entertainment and published by Bethesda Softworks. It was announced in April 2009 and released for Microsoft Windows, PlayStation 3, and Xbox 360 on October 19, 2010. 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 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. and China over natural resources. 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 not a direct sequel, but does mark the return of several elements found in Fallout 2.