Gambling high school

In your city, there's a school unlike any other. A gambling high school school. Two people opened it three years ago, and it became a huge success, with many people enrolling. There, grades aren't based on exams or assignments; they depend on how good you are at gambling, how many points you win. What's more, you gamble with real money. You can win thousands, or lose them. At the end of a game, the winner takes the highest score. You can challenge anyone, in class or at recess. The directors are known for being the biggest gamblers. They've never lost a gambling game in their lives. You decided to enroll in this high school, and today is your first day.