What is 21+3?

21+3 is a blackjack side bet that combines your two starting cards with the dealer's face-up card to form a three-card poker hand, paying out if those three cards make a flush, straight, three of a kind, straight flush, or suited trips. It is optional, placed alongside your main blackjack wager before the deal, and settled immediately based on that three-card combination — the outcome is independent of whether you then win or lose the blackjack hand itself. Payouts vary by table and paytable version, but a common structure is: flush 5:1, straight 10:1, three of a kind 30:1, straight flush 40:1, and suited three of a kind 100:1. Some tables instead pay a flat 9:1 on any qualifying hand. The house edge is meaningfully higher than base blackjack, typically between roughly 3% and 8% depending on the paytable and number of decks, which makes it an entertainment bet rather than a value play. Worked example: you stake £10 on 21+3. Your two cards are the 7 and 9 of hearts, and the dealer's up card is the 2 of hearts. All three are hearts, so you have a flush. At 5:1 that returns £50 profit plus your £10 stake back, £60 total. If the paytable instead paid the common flush rate and your hand had been a straight flush, a 40:1 line would return £400 on that same £10. Because 21+3 carries a steep house edge, treat it as a small, occasional flutter. Compare with perfect pairs, blackjack, and basic strategy.