How much you win depends on which three-card hand you get, with each one paying different odds, more of which below. If your first two cards plus the dealer’s up-card combine to provide one of these five hands then you win your 21+3 blackjack bet. Typically there will be a 21+3 box on the table in which you place your stake for the side bet. You place the bet before your cards are dealt. Suited three of a Kind – Three cards of the same value/face card and the same suit.Straight flush – Three cards of consecutive values that are all in the same suit.As you begin to play make sure to keep your basic strategy guide open on a separate window. Three of a kind – Three cards of the same value/face card Set a budget for yourself before you come to the table, and stick with it.Straight – Three cards of consecutive values, such as 2-3-4.In the 21+3 blackjack side bet you bet on whether the first two cards of your hand and the dealer’s face-up card combine to make one of the three-card poker hands below: It mixes blackjack and three-card poker to offer some attractive odds. Its challenging, exciting and easy to play. What is 21+3 blackjack? This popular side bet can be placed alongside your initial bet in the casino classic. Blackjack is one of the most popular casino card games in the world.