Princeton grad student Richie, believing he's been swindled, travels to Costa Rica to confront online gambling tycoon Ivan Block. Richie is seduced by Block's promise of immense wealth, until he learns the disturbing truth about his benefactor. When the FBI tries to coerce Richie to help bring down Block, Richie faces his biggest gamble ever: attempting to outmaneuver the two forces closing in on him.

Inferiorgangster Flying Dragon (Chin Ka Lok), has a bad habit of gambling, he thus offends the three great gamble deceivers. Luckily his younger cousin, Roy (Jordon Chan), who comes back from America is extraordinarily lucky, he can win every round of the game and saves Flying Dragon. Flying Gragon hence brings Roy to Mahjong casino to earm money for him. Roy observes the rivalry between two Mahjong geniuses Hua San Yuan (Yuen Wah) and Ge He Qing (Eric Kok) by chance, he witnesses the fate of them - one turns to be insane and one becomes bankrupt, and decides not to snatch the reputation of "The King of Mahjong". Though Roy has no desire to sieze the fame, his good luck elicits the worry of aggressive Mie Luo (Pang Jin Chi) who plans to ham Roy....