East Coast, Obsidian set the game in the American West.
It was specifically designed to be more of an expansion rather than a sequel Obsidian, however, saw the project as akin to the Grand Theft Auto titles Vice City and San Andreas - not numbered entries, but still full games in their own right. They knew the game would not be a direct, traditional sequel to Fallout 3, and it was referred to as ' Fallout 3.5' within Obsidian. Discussions for New Vegas began between Obsidian and Bethesda in 2008/09.
