21: Matt Boykin

The movie 21 follows the story of a young man who is desperate to earn money for his education and turns to the opportunity of gambling which present itself. He is talked into doing something that casinos try to stop but it is not considered illegal "counting cards". His initial intentions are to try to gain a scholarship in a respectful manner. When he goes to interview for the scholarship he is told there needs to be something that makes him stand out. His eventual story is almost overwhelming to his interviewer.
He does take up an offer to run a game on casinos in Las Vegas with other students and a professor. During his clime of fame and success he is eventual overwhelmed and backlashes against the man who taught him the system. In doing this he is dropped and betrayed by the one who taught him his new skill.
The one thing that stood out the most to me would be the idea of karma. What goes around comes around is a specific theme of this movie. The main character completely blows off his very close friends for his new more entertaining friends and is eventually cut out of a project at the last moment that he had been working on for a long time. Also the professor who betrayed the students also was dealt with swiftly and received his karma when he himself was double crossed by the main character.