Set in World War II, Casino Tycoon chronicles the story of Benny, a young graduate played by Andy Lau, who flees Hong-Kong during the Japanese invasion and heads for gambling haven Macau. Once in Macau, he impresses a local business man who has ties to organised crime, he slowly builds his way up in the ranks of the Macau underworld which ultimately leads to trouble.

Chan Ka Sing, Choi Kai Kwong and Lee Yuk Lan had been best friends since they were young. They hung out all the time at the lighthouse. Everything was fine until Ka Sing and Kai Kwong both fell in love for Yuk Lan. Compared to ambitious Kwong, Yuk Lan chose Ka Sing.