The game is set within a post-apocalyptic, open world environment that encompasses a scaled region consisting of the ruins of Washington, D.C. It was released worldwide in October 2008 for Microsoft Windows, PlayStation 3, and Xbox 360. The game marks a major shift in the series by using 3D graphics and real-time combat, replacing the 2D isometric graphics and turn-based combat of previous installments. The third major installment in the Fallout series, it is the first game to be created by Bethesda since it bought the franchise from Interplay Entertainment. Fallout 3 is a post-apocalyptic action role-playing open world video game developed by Bethesda Game Studios and published by Bethesda Softworks.