Fallout: New Vegas is set in and around a post-apocalyptic retro-futuristic Las Vegas, following the Great War between the U.S., and China as a conventional and nuclear war that occurred on October 22 - October 23, 2077, and lasted less than two hours, while causing immense damage and destruction. Before the Great War was the Resource Wars, during which the United Nations disbanded, a plague rendered the United States paranoid, and Canada was annexed. The city of Las Vegas itself wasn't hit as hard as most of the other districts, with most buildings being left intact as a result. The Hoover Dam supplies free electricity and water to those who control it.