'Fallout: New Vegas' Prequel Mod 'Fallout: New California' Release Date Set For October 'Fallout: New California,' a total conversion mod that will serve as the prequel to 'Fallout: New Vegas,' will be released on Oct. 23. The announcement of the five-year project comes after Bethesda teased the next 'Fallout' game, 'Fallout 76.' by Aaron Mamiit