How Does 21+3 Blackjack Work?

Some blackjack variations offer the 21+3 side bet to add a twist to the classic casino game. It takes its inspiration from three-card poker, using both your starting cards and the dealer’s upcard.

The following guide will explain how the 21+3 side bet works, the odds and payouts associated with it, and where you can play the 21+3 variation of blackjack. In closing, we’ll examine other blackjack side bets.

How the 21+3 blackjack side bet works

What is 21+3 in blackjack? With a 21+3 side wager, you’re betting that your two initial cards and the dealer’s face-up card will form a winning three-card poker hand. Here are the five combinations that can result in a bonus payout:

  • Flush — Three suited cards (example: 5♣ 7♣ J♣).
  • Straight — Three consecutive cards (example: 6 7 8).
  • Three of a kind — Three cards of the same rank (example: 5♣ 5♠ 5).
  • Straight flush — Three consecutive cards of the same suit (example: 5♠ 6♠7♠).
  • Suited three-of-a-kind — Three suited cards of the same rank (K♣ K♣ K♣).

If your first two cards and the dealer’s upcard form one of these combinations, you win according to the paytable. Note that the paytable may vary from one casino to another. The exact winning amount depends on the three-card hand you receive.

21+3 blackjack odds

The original version of 21 plus 3 blackjack had a 9:1 payout for all winning hands, and this paytable is still an option at various retail casinos across the country.

With the advent of legal real money casinos online, the paytable for 21+3 has shifted a few times. Depending on the blackjack variation and the software provider in question, the blackjack 21+3 payouts may vary from one casino site to another. For perspective, IGT’s version pays 35:1 for a straight flush, whereas Evolution Gaming’s live dealer blackjack variation with the 21+3 side bet pays 40:1.

Generally, for each of the five winning hands, the payout depends on the likelihood of that hand appearing. As the probability of landing the hand decreases, the better the associated payout.

The table below shows the most common odds and payouts for each hand at regulated online casinos. This is a live dealer variation from Evolution Gaming that uses eight decks.

Hand Payout Probability of Landing Total Number of Combinations Return
Flush 5:1 0.059 700,928 0.294
Straight 10:1 0.031 368,640 0.031
Three of a Kind 30:1 0.005 61,568 0.155
Straight Flush 40:1 0.002 24,576 0.082
Suited Three of a Kind 100:1 0.0002 2,912 0.024

House edge of 21+3

With the 21+3 side bet, the house edge depends on the number of decks in play. The difference can be as large as several percentage points.

The house edge on the eight-deck version cited above amounts to 3.62%. The six-deck version of the same game has a house edge of 3.7%, while the four-deck variant has a house edge of 6.39%. Some single-deck versions carry an abysmal edge of 13.39% for a 21+3 side wager.

So, is 21+3 worth it? Not really, considering that the house edge in blackjack using the optimal (basic) strategy is around 0.5%. For casual players, the difference may not seem significant, but for high-volume players, it can add up.

In short, it’s best to avoid side bets when playing blackjack. If you insist on trying your luck on 21+3, we recommend you pick the six-deck or eight-deck variant, which would offer the best possible value for the wager.

Where can you play 21+3?

The 21+3 side bet first became available in Las Vegas in 2001 and has since become a staple in land-based and online casinos across the US. Here are a few popular spots where you can try it out:

  • Regulated online casinos: Nearly all casino sites in the US have at least one blackjack variation with 21+3, including heavy hitters like BetMGM online casino, Caesars, and Golden Nugget online casino. Most notably, you’ll find the side bet at Ezugi– and Evolution Gaming-powered live dealer blackjack lounges. Some online casinos offer RNG-based 21+3 blackjack from IGT.
  • Vegas casinos: There are quite a few casino venues along the Strip that offer 21 + 3 blackjack, including MGM Grand, Caesars, M Resort, and Rampart Casino.
  • New Jersey casinos: Many Atlantic City casinos have a dedicated blackjack lobby. Tables with the 21+3 bet are available at the Tropicana and Hard Rock Casino.

Other blackjack side bets

Apart from 21+3, you’ll come across several other side bets in blackjack:

  • Insurance: This side bet allows players to protect themselves in case the dealer hits a natural. It is worth half of the original stake and is available when the dealer’s upcard is an ace. Insurance pays 2:1 if the dealer has a blackjack. The house edge for an insurance bet on a six-deck game is 7.4%.
  • Perfect pairs: This wager pays if the player’s first two cards form a pair. The payout varies depending on the type of pair (same suit, same color or mixed color).
  • Super 7s: This optional bet pays if you have one or more 7s in your hand. It pays 5000:1 if you get three consecutive suited 7s.
  • Lucky ladies: You are betting on getting a total of 20 from your initial two cards.
  • Over/under 13: A side bet on
    whether your two-card hand will add up to over or under 13. Aces count as one. Pays even money if successful.
  • Royal match: This is a bonus bet that pays if your first two cards are of the same suit. Depending on the combination, the payouts can be as big as 25:1 (suited queen and king).
  • Pair square: Similar to perfect pairs, pair square wins if the player’s first two cards are a pair or of the same suit. The payouts are bigger for suited pairs.