Reel Big Fish is playing at a game, and so that’s how you know the league is cool:
Most of the movie is Trey and Matt doing “psyche outs.” That’s when a player from the opposing team is about to shoot and you distract them with a sick burn or something gross (like Trey chewing on foil). When a psyche out works, it makes the player fall down somehow. Here’s a video of exactly what I just described: