Double Deck Blackjack Rules and Strategy: How It Plays and Costs

Double deck blackjack uses two standard 52-card decks, so 104 cards in all. You bet, you receive two cards, the dealer receives one face up, and you try to beat the dealer's total without going over 21. Only the pack changes. With fewer cards, each card you hold removes a larger share of the pack, which is what helps the player and what moves a few cells of the strategy chart. A short natural payout is common on these tables, and it is the main thing to check before you sit down. The BCLC rules of play describe the game as dealt either by hand or from a shoe. The New Jersey Division of Gaming Enforcement allows one or two decks only when the cards are dealt from the hand.

The steps below follow the BCLC section on double deck blackjack, and the table after them shows which rule comes from which document.

1. You place one bet. Every hand is settled against the dealer on its own.
2. You receive two cards and the dealer receives one, face up. There is no hole card.
3. If the dealer shows an ace, insurance is offered, paying 2 to 1. A player with a natural may take even money instead.
4. You hit, stand, double or split. There is no surrender.
5. When all players have finished, the dealer takes the second card. A natural ends the hand there.
6. The dealer hits 16 or less and also hits soft 17, then stands on any other 17 or more. Bets are settled.

What you can do with your hand#

You may double on any first two cards and receive one card only. Doubling after a split is allowed. Pairs may be split to a maximum of four hands, and two different ten-value cards count as a pair. Aces may be split once, each split ace takes one card, and two cards making 21 after a split are an ordinary 21 and not a natural. A natural against a natural is a push, and a natural pays 3 to 2.

Documented and assumed#

Regular blackjack here means the comparison game used across this site: six decks, the dealer hitting soft 17, doubling after a split and a 3 to 2 natural, with a hole card and a peek. Put next to it, double deck differs in two ways and looks the same in every other.

The missing hole card costs nothing here#

A game without a hole card is usually more expensive for the player, because a doubled or split bet can run into a dealer natural. Under the BCLC rule that cost disappears: the extra stake is returned. On the six-deck comparison rules, a no-hole-card game where the dealer natural takes only the original bet moves the house edge by +0.00 points (Change in the house edge against the reference rules (6 decks, dealer stands on soft 17, blackjack pays 3 to 2) when only this changes: no hole card, dealer natural takes the original bet only. Positive means the house gains, negative means the player gains. The difference of two exact house edge figures.), the same as a game with a hole card. The Venetian, Red Rock and Hard Rock Atlantic City guides describe face-down second cards on their tables, which play the same way when only the original bet is at risk. Check the table you face for this rule. The glossary explains the two procedures.

The house edge is the average share of your starting bet that the house keeps over a very long run. It says nothing about one session.

The figure for these rules is 0.39% (Double deck blackjack. House edge per starting bet: the average loss per round as a share of the bet placed before the cards are dealt, doubles and splits included in the result. Rules: 2 decks, dealer hits soft 17, no hole card, a dealer blackjack takes only the original bet, blackjack pays 3:2, double on any first two cards, double after split, split up to 4 hands, aces are not resplit, one card to each split ace, no surrender. The player follows the printed strategy chart for these rules from a full shoe, and never takes insurance or even money.). The same two-deck game with the dealer standing on soft 17 comes to 0.19%, so the dealer's soft 17 rule accounts for the gap between the two figures. Two decks alone take 0.23 percentage points off the comparison rules. Six decks with the dealer standing on soft 17 give 0.41%, and a single deck on the comparison rules gives 0.05%. The deck count helps, and every other rule still counts.

A natural comes one hand in 1 in 20.9 (The chance of a natural as one hand in so many. Rules: 2 decks. Worked out exactly from a full shoe.) with two decks, against one in 1 in 21.1 (The chance of a natural as one hand in so many. Rules: 6 decks. Worked out exactly from a full shoe.) with six. The difference is small, and it is one of the reasons the game favours the player.

The house edge calculator lets you change the payout, the dealer rule and the doubling rules and read the result. The methodology page explains how the figures are calculated.

The house edge above assumes a natural that pays 3 to 2. Many double deck tables do not. The Hard Rock Atlantic City guide says that on single or double-deck games a natural is paid 6 to 5. The Venetian and Red Rock guides say a natural pays 6 to 5 or 3 to 2 depending on the game, and the BCLC rules of play also cover a 6 to 5 blackjack game and say every rule except the natural payout is unchanged.

On a 10 unit bet a 3 to 2 natural pays 15 and a 6 to 5 natural pays 12. Over a long run, paying 6 to 5 instead of 3 to 2 adds +1.36 points (Change in the house edge against the reference rules (6 decks, dealer stands on soft 17, blackjack pays 3 to 2) when only this changes: blackjack pays 6 to 5. Positive means the house gains, negative means the player gains. The difference of two exact house edge figures.) to the house edge on the six-deck comparison rules, which is more than any other single rule in the calculator. No figure is given here for double deck paying 6 to 5, because the game is computed only at 3 to 2. Read the payout printed on the felt first. If it says 6 to 5, the deck count does not save you. The single deck page works through the figures.

Double deck strategy is regular blackjack strategy with a few cells moved. Against the six-deck comparison chart, four cells of the first-two-card charts change, and the chart below marks them.

The four cells that change#

• Hard 9 against a dealer 2 doubles, where the six-deck comparison hits.
• Ace and 3 against a dealer 4 doubles, a close call, where the comparison hits.
• A pair of sixes against a dealer 7 splits, where the comparison hits.
• A pair of sevens against a dealer 8 splits, a close call, where the comparison hits.

Why no hole card does not change the chart#

Because the original-bet-only rule returns the extra stake, hard 11 doubles against every dealer card, an ace included, and eights split against a dealer ace. In a game where a dealer natural takes every bet, these are the cells that get cut back. Here they are not. The European blackjack page shows what the chart looks like when the extra stake is at risk.

The table below deals two decks with no hole card: the dealer's second card appears only after you finish, and a dealer natural settles at that point. Nothing is wagered and nothing can be won.

Real-money blackjack is licensed, and where it is offered is decided place by place. If you want to know what is available near you, ask your local gaming regulator. No venues or operators are named here. A game of chance stays a game of chance, and the house edge above is a long-run average. If gambling stops being fun, the responsible play page lists where to get help.

One name covers several tables. The documents show these differences.

• Soft 17. BCLC has the dealer hit. No official document retrieved for this page covers a Las Vegas double deck game, so the dealer rule there is not stated.
• Resplitting aces. BCLC allows aces to be split once. The Venetian guide says re-splitting aces is not available on its double deck game.
• Surrender. Not offered in the BCLC rules, the Venetian guide or the Red Rock guide.
• Payout. 3 to 2 in BCLC, 6 to 5 or 3 to 2 at the Las Vegas resorts, 6 to 5 at Hard Rock Atlantic City.
• Hole card. None in BCLC, a face-down second card at the Venetian, Red Rock and Hard Rock Atlantic City.

Side bets sit on top of the main game and are judged on their own. The side bets page covers them.

The rules and the original-bet-only treatment come from the BCLC rules of play for table games, which is the only complete published double deck rule set found. BCLC is a provincial lottery corporation, not a gaming regulator, so it is named here as a rule document and does not appear in the regulator list below. The Venetian, Red Rock and Hard Rock Atlantic City guides are casino sheets and are used for the variations only. The New Jersey Division of Gaming Enforcement is cited for deck counts and the 6 to 5 variation. About this site explains how sources are handled.