Crab Chan (Andy Lau) and Sam Law (Alan Tam) are childhood friends who are outstanding gamblers. But while Crab went to prison for 3 years for gambling swindling, Sam went on to be the best gambler in all of Asia. Upon exiting prison, Crab is picked up by Bobo (Rosamund Kwan), who becomes his assistant/lover.

Sam and Crab are asked by his friend Lon (co-director Charles Heung) to come to Las Vegas to investigate possible fraud by international gamblers. While in Las Vegas, the pair meet a beautiful rich girl, Miss Tong Koyan (ex-CYF girlfriend Idy Chan), who is living up life in Las Vegas for a week, including paying $1,000 per night for escort service. Sam and Crab manage to detect the scam, which raised the ire of the Japanese Yakuza. At the same time, Sam and Tong become closer and closer. The combination of gambling, the Yakuza, and wealth lead to a interesting rest of the movie.

A bit of a spoiler, the very last line in the movie that Sam spews out probably could have been better subtitled to capture the emotion. It could have been interpreted as "I'm going to continue fooling her"....

This movie in many respects was the start to a slew of gambling movies, including God of Gamblers. Though God of Gamblers is credited with being the movie that started the gambling movie craze, in actuality Casino Raiders was out a few months before, with very good box office success.