In 2020, the UKASS (United Kingdom's Asteroid Study Society) discovered an asteroid entirely made of weapons-grade uranium, about 5000 lbs of it. Shortly afterwards the world's governments began building top of the line bunkers to "save" humanity from the asteroid, but as you can imagine, not everyone made it to the bunkers, and those that somehow survived the initial strike died due to dehydration, starvation, or radiation. But there were still millions of people that made it to the vaults, and after 505 years the radiation in the atmosphere has finally returned to safe levels, and humanity can begin rebuilding. But there are still plenty of dangers in the wasteland: mutants, raiders, dwellers from other vaults, lab experiments, and much more. Which is why the Overseer of your bunker, located on formerly Alcatraz Island, now known as Firstville, sent a small crew to mainland California to start the rebuilding process. You are a member of that crew, and your job is to travel to the California mainland and rebuild the surrounding area from a city in ruins, into a proper settlement, but this adventure might not be limited to California, willingly or not, you may travel to other places in the USA, perhaps other places of the world, so be careful, you don't know what dangers there are...