Colin Farrell plays a high stakes gambler in Macau.
The game is Punto Banco = Baccarat which is a game of pure chance.
It is a bet on a duel between Punto (the player) and Banco (the banker).
The score is counted modulo 10. The one closest to 9 wins.
Cards 2-9 are their nominal value. 10, Jacks, Queens and kings count 0
an ace counts 1. Then there are fixed automatic rules to get a third card.