Casino Royale by Ian Fleming

Casino Royale is Ian Fleming's first James Bond novel. It would eventually pave the way for 11 other novels by Ian Fleming himself, in addition to two short story collections, followed by many "continuation" Bond novels by other authors.
Since first publication on 13 April 1953, Casino Royale has been adapted for the screen three times. The first was a 1954 episode of the CBS television series Climax! with Barry Nelson as CIA agent "Jimmy Bond". The first Casino Royale film was a 1967 spoof with both David Niven and Peter Sellers playing "Sir James Bond"; the second was the twenty-first official film in the EON Productions film series with Daniel Craig as James Bond, released November 17, 2006.
The Head of MI6 assigns James Bond to play in a high-stakes baccarat game at the Royale-Les-Eaux casino against and bankrupt Le Chiffre. As part of James Bond's cover as a rich Jamaican playboy, M also assigns as his companion Vesper Lynd, personal assistant to the Head of Section S (Soviet Union). The French Deuxième Bureau and the CIA also send agents as observers. James Bond initially considers Vesper simply as a nuisance, but grows to have romantic feelings for her.
The game soon turns into an intense confrontation between Le Chiffre and James Bond; Le Chiffre wins the first round, bankrupting Bond, and Vesper refuses to stake him any higher. As James Bond contemplates killing Le Chiffre outright, CIA agent Felix Leiter offers to stake James Bond for another hand, with the condition that the CIA gets to bring Le Chiffre in. James Bond accepts the money and the game continues... (Summary by Wikipedia)