Players at the top of the leaderboard at the closure of play will win the top prizes. Once tournament gameplay begins, points are compiled based on the performance of each hand. Simply find a tournament that suits you best and sign up for it. Online casinos feature schedules of upcoming 21 tournaments that detail the times, entry fees, prize amounts, and rules involved. These casinos offer legal online blackjack in most US states, and they each have scheduled contests available for browsing right now. If there are no domestic casinos located near you, the best option is to sign up at an offshore blackjack casino operating legally online. These types of online blackjack tournaments require players to be in the same state as the gambling facility hosting the events, and sometimes players even have to be on the premises of the casinos themselves. A few states that have laws regulating Internet gambling have opted to offer online table games through their physical casino properties. Yes, playing 21 tournaments online is legal, and there are several options for doing this. Is It Legal To Play Online Blackjack Tournaments For Real Money?