"Fallout", an ongoing series of post-apocalyptic role-playing games first published in 1997, depicts a world after a series of resource wars that culminates in a massive nuclear exchange between the U.S and China in 2077. The games revolve around "vaults," underground bunkers for long-term survival (in reality social experiments created by the ruling elite of the pre-war United States), and exploring the outside wasteland, in locations such as California, Las Vegas, Washington D.C., New England, and West Virginia. "Fallout" draws heavily from retro 1950s sci-fi, and the setting combines elements of mid-20th century technology, such as vacuum tubes and monochrome screens, with highly advanced artificial intelligences and energy weapons.