21+3 Blackjack Side Bet

A comprehensive guide on the 21+3 blackjack side bet from the payouts and odds to the 21+3 rules and strategies to use to reduce the house edge.

21+3 is an exciting and fun blackjack variation that is played as a side bet in a standard game. This side wager comes across as a mix of basic blackjack and three-card poker and promises some attractive odds for the players.

What Is The 21+3 Blackjack Side Bet?

The 21+3 side wager in blackjack is a bet that the player's original two cards combined with the dealer's up card will make a winning poker hand. The three combined cards can lead to:

  • a Flush (three cards of the same suit like J42),
  • a Straight (three cards of consecutive values like 345),
  • a Three of a Kind (three cards of the same denomination like 888),
  • a Straight Flush (three cards of the same suit and with consecutive values like 89T), or
  • a Suited Three of a Kind (three cards of the same denomination from the same suit like 555).
21+3 Side Bet (Blackjack): Odds and Payouts
21+3 Side Bet (Blackjack): Odds and Payouts

21+3 Blackjack Rules

21+3 blackjack rules are the simple and standard ones. The game is usually played with 6 decks of cards. The dealer stands on all 17s. Players are allowed to double down on 9, 10, and 11 values. When a player doubles down, he receives just one additional card. Also, players are allowed to split up to 2 blackjack hands including the Aces. Doubling down after a split is also allowed. The standard blackjack pays 3:2.

The 21+3 side bet offers different ways to win for the players. Accordingly, this blackjack side bet payout varies depending on the combination the player receives from his two cards and the dealer's up card. A Flush pays 5/1, Straight pays 10/1, Three of a Kind pays 25/1, Straight Flush pays 40/1, and Suited Three of a Kind pays 100/1. As you can tell, these are similar to poker hands in terms of card combinations.

How To Play Blackjack 21+3

The blackjack game starts in the usual way with every player being dealt two cards. The dealer gets one card face up and another, face down. Typically, the blackjack table will have a 21+3 box in which the player can place the stake for this wager. If the first two cards of the players combined with the dealer's up card provide one of the following hands, then the player wins the 21+3 blackjack side bet. If not, he loses the bet amount. The winning amount also varies depending on the hand the player gets. Each hand offers different statistics in the gameplay as delineated below:

Three of a Kind

A player can get Three of a Kind, which implies three cards of the same value or face cards. These cards can belong to the same suit making for a Suited Three of a Kind hand, which pays the maximum that is 100. In a standard game with 6 decks of cards, the probability is 0.000207 with an RTP of 0.020745. When the cards are not from the same suit, a winning hand pays 33 and offers a probability and RTP of 0.005041 and 0.166352 respectively. The odds are quite high at 1:199.


A Flush is a combination of three cards of the same suit. In a standard 6 deck game, a Flush pays 5 and with a combination of 292896, it guarantees a probability of 0.058424 and RTP of 0.292118. The probability and RTP (with the Flush and the rest of the factors remaining the same) for a game of 8 decks of cards would be 0.058841 and 0.294207 respectively.


A Straight is a very interesting hand in the 21+3 blackjack side bet. It means that the initial two cards of the player and the dealer's up card are of consecutive values such as 345. Such a hand pays 10 and has odds of 10:1 in a blackjack game with 6 decks of cards. The probability and RTP for a Straight are 0.031021 and 0.310214 respectively.

Straight Flush

A Straight Flush hand calls for three cards of consecutive values as well as from the same suit. In a standard game, a Straight Flush pays 30 with an odd of 1:499. The combination, probability, and RTP would be 10.368, 0.002068, and 0.062043 respectively. Because this is the hand that beats nearly everything else in poker, your odds of forming this one are incredibly low.

Odds of 21+3 in Blackjack

The original 21+3 side bet is paid out 9:1 for a winning hand, which results in a house edge of about 3.24%. However, the house edge can vary depending on the blackjack table you are sitting at and the casino you are playing in. Also, the different variations of the 21+3 side bet have house edges ranging from 2.78% to 13.39%.

That being said since the theoretical RTP of this wager is 95.38%, the standard house edge can be considered to be 4.62%. Compared to many other side bets, the house edge of the 21+3 side bet seems to be quite reasonable, especially because the wager gives multiple options for the players to win. Here is an overview of the statistics of the 21+3 hand in a standard blackjack game with 6 decks.

21+3 HandCombinationsProbabilityPayoutOdds
Three of a kind252720.005041331:199
Straight flush103680.002068351:499
Suited three of a kind10400.0002071001:4999
List of 21+3 Blackjack Odds

Where To Play 21+3 Blackjack?

The 21+3 side wager is a comparatively newer addition to blackjack. As a result, in spite of being popular and loved by blackjack players, it is not quite widely available in casinos.

Where to play 21+3 online

Online gaming software and casinos have somewhat made this 21+3 side bet popular. Among the most notable ones, there is Wager Works which offers the IGT blackjack. In it, the 21+3 blackjack is played with 6 decks of cards and the standard rules remain the same.

Felt Gaming and Evolution Gaming also have their 21+3 blackjack variation for players. Playtech has recently launched its online blackjack with a 21+3 side bet. The Royal Panda live blackjack is also well-known and is basically an online live dealer blackjack game offering 21+3 side bets.

Where to play 21+3 in land-based casinos

The 21+3 side bet commonly accompanies the European blackjack variation and therefore, it can be found in a few casinos in Europe. In Las Vegas too, you can play the 21+3 blackjack in casinos like Vegas Ace.

Blackjack 21+3 Payout
Blackjack 21+3 Payout

21+3 Blackjack - FAQ

Our answers to the most common questions about the 21+3 side bet in the game of blackjack.

What is 21 plus 3 in blackjack?

21+3 is a side bet in blackjack. It is placed on the expected outcome of the player's first two cards and the dealer's up card forming certain combinations such as Flush, Straight, Three of a Kind, Suited Three of a Kind, and Straight Flush.

Is 21+3 part of the standard blackjack game?

The 21+3 is an additional side wager and part of a regular blackjack game. However, it depends on the casino and the blackjack table whether placing this side bet would be allowed.

What are the odds of getting suited trips in 21+3 blackjack?

The odds of getting Suited Trips or Suited Three of a Kind in 21+3 blackjack would be as high as 1:4999.

What are the payouts like in blackjack 21+3?

The payouts vary depending on the hand that the player receives. In a standard game, a Flush pays 5, Straight pays 10, Three of a Kind pays 33, Straight Flush pays 35, and Suited Three of a Kind pays 100.

How to play casino 21+3 blackjack with top 3?

The Top 3 is a second house-banked optional proposition wager used in the game of blackjack in conjunction with the 21+3 wager.
It is offered on blackjack tables with the 21+3 wager and is available only for 4, 6, and 8 deck shoe games. Players can only make the Top 3 wager if they make the 21+3 wager along with their blackjack wager. The Top 3 wager is based on a three-card hand using the dealer's one-up card and the player's two initial up cards to form a three-card poker hand.

Can you play 21+3 blackjack online?

21+3 blackjack side bet can be played in various online casinos. The blackjack variation is powered by quite a few developers such as Evolution Gaming and Playtech.

How do you know if 21+3 is available at a blackjack table?

Any game of blackjack that will allow this 21+3 side bet will have a separate 21+3 side bet box placed on the table itself for the bet to be placed.

Can you use card counting with a 21+3 blackjack bet?

Card counting is a method of assigning value to specific cards and running a true count, allowing you to get a good idea of what cards are left in the deck and what the dealer is holding. An accurate true count allows players to improve their chances of knowing when a 21+3 hand is in play.

Do professional blackjack players take the 21+3 bet?

Like the insurance side bet, the 21+3 bet is luck-based. There is no means to guarantee to win this side-bet most of the time, even with a card counting strategy. Because of this, professionals are likely to avoid the 21+3 side bet.

The 21+3 side bet is quite interesting and often loved by blackjack players. It is also a popular blackjack side bet because it is widely played in online casinos.