All About the 21+3 Side Bet, a Fan-Favourite Side Bet in Blackjack

Staff Writer Tips & Tutorials 740

We always talk about blackjack as one of the best casino games because it involves lots of skill, and not just luck. Well, blackjack is also fun because it’s a game full of variations – and the best way to introduce flexibility into the rigid table game is with side bets.

Today’s article is a comprehensive guide to the 21+3 side bet, perhaps the most famous side bet in all blackjack games. See what betting on 21+3 looks like, what benefits it brings, and how to use it to your best advantage.

What Is the 21+3 Side Bet?

21+3 is a side bet in blackjack that links blackjack to poker rules.

As a side bet, it is not the main bet, and therefore, not the only type of bet you can play per round. In other words, you are probably not going to be able to place the wager if you haven’t joined the round in the first place.

Now, the link with poker. The 21+3 means the game takes the two cards dealt to the player and the one face-up card dealt to the dealer. If these three cards collectively create a type of poker hand, you get a payout. Poker hand rankings follow the three-card poker rules, which we will explain in detail below.

To sum up what we’ve learnt so far:

  1. 21+3 is a side bet in blackjack.
  2. It combines the player’s two and the dealer’s one card to create a 3-card combo.
  3. The combo must be a valid poker hand to pay out.
  4. Poker hand rankings follow the three-card poker rules.
  5. You must enter the round to place the side wager on 21+3.

Not bad, right? It’s a perfect side bet for all players who enjoy both blackjack and poker. Of course, even if you are not fluent in the two gambling games, there’s no reason to worry! Should you win, you will automatically receive your payout according to the paytable (and poker hand rankings).

How Does the Side Bet Work

Placing the side bet is pretty much self-explanatory.

The only thing you need to do is join the round – by placing the original wager and entering the round. During the betting phase though, you place the side bet as well.

The actual procedure truly depends on the game you are playing. It might be different from provider to provider, table to table – and there might be slight differences between online and live blackjack games. But regardless, you still need to place a main bet and then wager on the side bet. You pick the amount you wish to wager on 21+3 and then that’s it.

After placing the bets, the dealer will start the round and deal the cards. You will know if you’ve won anything as soon as the cards are placed on the table.

For this bet, you need to consider the two cards you’ve been dealt, and the one card dealt to the dealer’s hand. If those three cards form a poker hand, you get a payout (in most cases, instantly).

The payout depends on the poker hand in question. You can trigger one of five options.

21+3 Poker Hand Rankings

Here is a list of the five hands that could get you a win if you bet on 21+3 in blackjack,

  • Flush – Three cards matching in suit but not in a sequence
  • Straight – Three cards in a sequence but not matching in suit
  • Three-of-a-kind – Three cards of the same value irrespective of suit
  • Straight Flush – Three cards matching both in suit and in a sequence
  • Suited Three-of-a-kind – Three cards matching in value and suit

Please note that Aces can have either Low or High values when it comes to forming poker hands. Also, a sequence can be any line such as A-2-3 or 3-4-5 or 6-7-8, etc. the odds are always more in favour of the players, as this is a generally quite a player-friendly side bet. That means the payouts are also quite generous, and far from the classic 3:2 or 2:1. Instead, you might even win up to 100:1! This payout is typically reserved for the Suited Three-of-a-kind, which is the hardest to strike.

Why Is 21+3 So Popular?

The answer to the popularity of 21+3 lies in the overall interest in blackjack side bets. In general, there are several side bets most blackjack games come with now. The most common, besides this one, are Perfect Pairs, Over/Under 13, Lucky Ladies, and Dealer Bust. Sure, the game might include additional wagering options (one that most games include but is not advisable to use is Insurance).

In general, the use of side bets might not be a complicated thing to learn. And it’s fun, it really is – but is adding extra weight to the betting sum a good option in every single case? Of course not.

For instance, if you see you are slowly entering a dry spell, no betting is better than main or side betting. Quit the game altogether to cut losses!

But if you are looking to add an extra layer of fun to the experience, placing a side bet here and there might get you there in no time.

Another reason why 21+3 betting is common is the mix of poker and blackjack. To be honest, many players adore poker, but it’s a complex game to master. Not that blackjack is easy!

But it’s always a great thing to see when providers and casinos combine two games into one. And playing side bets that link you to your other favourite game is always cool.


There you have it – the 21+3 side bet in blackjack is nothing complicated, just pure fun! It’s one of many side bets you can enjoy whilst playing online blackjack, both in RNG and live mode. If you like our guide to 21+3 blackjack side betting, stick around as we’ll explore other blackjack side bets and deliver surefire blackjack strategies that’ll ensure you always have a good time playing blackjack for real money.


BestCasinos team consists of online casino experts dedicated to spreading their knowledge and experience to a wider audience, all in effort to help even the most inexperienced players gain their footing in this exciting industry.