Watch 21 for Free: How to Stream the Movie Online at 123Movies. . Ben Campbell is a young, highly intelligent student at M.I.T. who strives to succeed. Wanting a scholarship to transfer to Harvard School of Medicine to become a doctor, Ben learns that he cannot afford the $300,000 tuition as he comes from a poor, working-class background. But one evening, Ben is introduced by his unorthodox math professor to a small but secretive club of five students, Jill, Choi, Kianna, and Fisher, who are being trained by Professor Rosa to count cards at blackjack.