The Griswolds are off on a family outing to Las Vegas, where they each have their own misadventures. Hapless dad Clark Griswold immediately starts losing money at blackjack, while his wife, Ellen, develops a crush on lounge performer Wayne Newton. Elsewhere, young Rusty is enthusiastically playing dice, and his sister, Audrey, winds up in seedy nightclubs. Can the family reunite and stay out of trouble?