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21+3 blackjack myths and misconceptions – what you need to know

June 10, 2025

21 + 3 is a popular side bet that many choose to play when playing Blackjack at an online casino. The bet can be placed at the start of every hand and any stakes are needed to be made before the dealer deals out the cards.

21 + 3 is one of two side bets that can be made before the start of a hand, with the other being Perfect Pairs. Whereas Perfect Pairs are purely focused on the two hole cards that the player receives, 21 + 3 is different as it takes into account both of the players cards and the one upturned dealer card.

The reason why 21 + 3 has turned into a popular side bet is largely down to the fact that it actually encompasses two different games, Blackjack and Three Card Poker – the Poker element of the bet is represented by the ‘3’ in the actual bet title.

Although 21 + 3 has been a side bet that has been in both real and online casinos since the 1990s, it is arguably the one side bet in Blackjack that people know the least about, and over time there have been many myths and misconceptions that have arisen.

Let’s dive into what some of these myths are in a little further detail.

What actually is a 21 + 3 bet?

Before we delve into the myths that have arisen from a 21 +3 bet, let’s first of all spend some time looking at what a 21 + 3 bet actually is.

As we have explained above, it uses three cards, the two cards that the player uses and the one card that the dealer starts every hand with. That is the Blackjack element of the bet over, the rest of the bet now shifts over to the three card poker dimension.

The focus of the bet is to make a three card poker hand from the three live cards – the potential hands that can be generated are ranked in the following order.

  • Suited Three of a Kind: three cards of the same rank and suit.
  • Straight flush: three sequential cards of the same suit.
  • Three of a Kind: three cards of the same rank and any suits.
  • Straight: three sequential cards, e.g., 9-8-7, of any suits.
  • Flush: three cards of the same suit in any order.

Depending on the type of hand that you can generate, different odds are applied depending on how likely they are to occur.

  • Flush: 5/1
  • Straight: 10/1
  • Three of a Kind: 30/1
  • Straight Flush: 40/1
  • Suited Three of a Kind: 100/1

It is important to note that there is no swapping of cards when placing a 21 + 3 bet. The fate of the bet very much lies in the cards that are dealt.

Breaking down the myths and misconceptions of the 21 + 3 side bet.

It’s all about making 21

Arguably the biggest myth that needs to be busted when talking about a 21 + 3 bet is the fact that the side bet has nothing to do with making 21 at all.

The focus of the bet is purely focused on poker and aside from the cards that are dealt, that’s as far as the Blackjack element goes.

If you place a 21 + 3 bet whilst the two cards that you are dealt will contribute to your Blackjack bet that you would have staked, those partaking in 21 + 3 need to focus purely on trying to make one of the three card poker hands that we have clarified above.

The 21 + 3 bet will actually be settled before any action on the table begins. You will know if your hand is a winner or a losing one and any winning bets will be settled before you decide to hit or twist. 

Once all of the side bets on the table have been determined, the Blackjack element of the hand using the two cards that you have been dealt will then begin. 

It is possible that you could win twice, once with the main Blackjack bet and once with the 21+3 bet. It is possible that you could win the main Blackjack hand or lose the 21 +3 side bet, this can of course work the other way as well. Or you could lose both hands. You could fail to hit a 21 + 3 hand and you could bust out. It’s important to remember that if you place a side bet, there are no guarantees that the hand will win.

Placing a 21 + 3 side bet increases your overall chance of winning

When it comes to knowing what the different Blackjack side bets are, it’s fair to say that Perfect Pairs, taking the Double and Insurance are all better known than the 21 + 3 bet. The reason behind this is out of all the different side bets that can be placed, statistically the 21 + 3 is the hardest one to hit when playing Blackjack in a live casino

Out of all of the different side bets, the 21 + 3 offers the house the biggest advantage, so it’s common that you will lose more than you win if this is a bet you want to place regularly.

Due to odds being against the players, the odds for winning a 21 +3 bet are generous and this is something that should be factored when deciding whether this is a bet you want to get involved in or not.

A 21 + 3 side bet is difficult to understand

It’s easy to believe that because the 21 + 3 bet combines both Three Card Poker and Blackjack into one simple and easy bet, the bet itself is actually hard to understand. This isn’t actually the case.

For those that play poker, the hands and how they are constructed should be easier to follow, the fact that you are only dealing with three cards in comparison to five cards should make working out what you have even more simple.

If poker isn’t a game you have much experience in, it’s important to know that the winning hands in a 21 + 3 side bet are more condensed than what you would expect to find in a standard game of Texas Hold Em. Just like when playing any new game, the rules to begin with could be a little tricky to get your head around, but with only five winning outcomes possible, the learning curve can be pretty quick once you understand the basics.

Placing a 21 + 3 bet will reduce the overall chances of hitting Blackjack

As we have already outlined, the 21 + 3 bet is a side bet that is concluded before the main Blackjack betting begins. If you want to get involved in a 21 + 3 bet it has no bearing on whether you will win the Blackjack component of the hand.

Before you decide to hit or stick, the result of the 21 + 3 side bet would have been concluded and you can be free to play the Blackjack element of the hand knowing that it has no impact on the 21 + 3 side bet you might have placed.

It works the same way if you have been dealt Blackjack by the dealer. The combination of the Ace and ten card you would have received will apply for both the Blackjack part of the bet and the 21 + 3 bet. Therefore if you are dealt Blackjack, that will be a winner, if the dealer has a card that will help you land a 21 + 3 side bet then you could be a winner of the side bet as well.

How decks of cards are shuffled varies between standard online Blackjack and Live Blackjack

You can’t place a Perfect Pair and a 21 + 3 side bet at the same time

One of the biggest myths around Blackjack side bets is that you can only place one of the Perfect Pairs or 21 + 3 side bets, that isn’t actually true.

At the start of any Blackjack hand you can place three bets, the main Blackjack bet, and the two side bets, Perfect Pairs and 21 + 3. The thing to remember if you want to get involved in the side bets, is that the table minimums have to be met. You could have three bets on the table with differing amounts, but all must meet the minimums as determined by the table you are sat on.

There isn’t a limit to the amount of side bets that you can get involved in. For example, if you want to place the two side bets, you could also take up the offer of Insurance or even commit to a double. The thing you have to remember is that getting involved in all of the different side bets that Blackjack operates can be expensive and can see your overall bank balance quickly decrease.

Written By
David Lynch

Experienced writer and editor based in Ireland. Attends poker events, covers all casino games and slots, but is really a keen blackjack and roulette player at heart. A sports fanatic among all other things with a soft spot for soccer and F1