The movie 21 manages to be captivating thanks to a compelling real-life narrative, brisk tempo, and engaging personalities. It’s an enjoyable watch centered around the MIT Blackjack Team’s experiences attempting to count cards in Las Vegas and achieving considerable success. Though it doesn't break new ground regarding its plot or how it’s presented, 21 offers a pleasant experience with a clever turn of events and characters that are easy to root for. What distinguishes this film from standard robbery movies is the fact that card counting isn't actually against the law. The people involved weren't attempting to evade law enforcement but rather casino security personnel who resort to intimidation tactics. The relatively unfamiliar cast delivered commendable performances, enhanced by the movie’s quick pace and thrilling storyline.

Source on TMDB