Super Fun 21 is a variation of Blackjack with several rule differences that change the gameplay. In this version, a blackjack pays 6:5 instead of the standard 3:2, and a player's blackjack beats the dealer's blackjack. Players can surrender early, offering a chance to forfeit half their bet before the dealer checks for a blackjack. There’s more flexibility with doubling down, as players can do so at any time, even after splitting cards. Additionally, players can split up to four hands, and can even double down on split Aces. The dealer wins all ties except when both the player and dealer have a blackjack. These changes make the game more dynamic, but the lower payout for blackjack can be a disadvantage compared to regular Blackjack.