Blackjack (also known as Twenty-one, Vingt-et-un (French for Twenty-one), or Pontoon) is the most widely played casino banking game in the world. Much of blackjack's popularity is due to the mix of chance with elements of skill, and the publicity that surrounds card counting (calculating the probability of advantages based on the ratio of high cards to low cards). The casino version of the game should not be confused with the British card game Black Jack (a variant of Crazy Eights).
When 21 was first introduced in the United States it was not very popular, so gambling houses tried offering various bonus payouts to get the players to the tables. One such bonus was a 10-to-1 payout if the player's hand consisted of the ace of spades and a black Jack (either the Jack of clubs or the Jack of spades). This hand was called a "blackjack" and the name stuck to the game even though the bonus payout was soon abolished. As the game is currently played, a "blackjack" may not necessarily contain a jack or any black cards at all.
Each player's goal is to beat the dealer by having the higher, unbusted hand. Note that if the player busts they lose, even if the dealer also busts. If both the player and the dealer have the same point value, it is called a "push", and neither player nor dealer wins the hand. Each player has an independent game with the dealer, so it is possible for the dealer to lose to some players but still beat the other players in the same round.
The minimum/maximum bet is printed on a sign on the table and varies from casino to casino and table to table. After initial bets are placed, the dealer deals the cards, either from one or two hand-held decks of cards, known as a "pitch" game, or more commonly from a shoe containing four or more decks. The dealer gives two cards to each player including himself. One of the dealer's two cards is face-up so all the players can see it, and the other is face down. (The face-down card is known as the "hole card". In European blackjack, the hole card is not actually dealt until the players all play their hands.) The cards are dealt face up from a shoe, or face down if it is a pitch game.
In American blackjack, if the dealer's face-up card is an ace or a ten-value, the dealer checks their hole card to see if they have a blackjack. This check occurs before any of the players play, but after they have been offered insurance (if the face-up card is an ace). If the dealer has blackjack, all players lose their initial bets, except players who also have blackjack, who push. (In some American casinos, the dealer does not actually check the hole card until after the players have all played. At that time, if the dealer turns out to have blackjack, all players who did not have blackjack lose their bets, and players who increased their bets by doubling or splitting lose only the original bet, and have the additional bets returned to them; thus, the end result is precisely as if the dealer had checked the hole card before playing.)
A two-card hand of 21 (an ace plus a ten-value card) is called a "blackjack" or a "natural", and is an automatic winner (unless the dealer has blackjack as well, in which case the hand is a push). A player with a natural is usually paid 3:2 on his bet. Some casinos pay only 6:5 on blackjacks; although this reduced payout has generally been restricted to single-deck games. This reduced payout for a natural increases the house advantage over a player by as much as 1000 percent. The move was decried by longtime blackjack players.
signal: (handheld) scrape cards against table; (face up) touch finger to table
signal: (handheld) slide cards under bet; (face up) move hand horizontally
signal: place additional chips next to (not on top of) original bet, make "one finger" sign
signal: place additional chips next to (not on top of) original bet, make "two fingers" sign
signal: make 'chopping' motion over bet (signal is rare, usually just done verbally)
Hand signals are required in most casinos, so that in case of a dispute, a video record exists of the player's decisions.
The player's turn is over after deciding to stand, doubling down to take a single card, or busting. If the player busts, he or she loses the bet even if the dealer goes on to bust.
After all the players have finished making their decisions, the dealer then reveals his or her hidden hole card and plays the hand. House rules say that the dealer must hit until he or she has at least 17, regardless of what the players have. In some casinos a dealer must also hit a soft 17 (a combination of cards adding up to either 7 or 17, such as an ace and a 6).
If the dealer busts then all remaining players win. Bets are normally paid out at the odds of 1:1. Players who push (tie) with the dealer receive their original bet back .
Each blackjack variation has its own set of rules, strategies and odds. It is advised to take a look at the rules of the specific variation before playing. Many countries have legal acts and laws which determine how a casino game of blackjack must be played. Not all rules are posted. The player has to ask, either beforehand or when the situation occurs. Over 100 variations exist.
There are two slightly different dealer strategies. In the "S17" game, dealer stands on all 17s. In the "H17" game, dealer hits on soft 17s; of course, he stands on hard 17s. (In either case, the dealer has no choice; he must or must not hit.) The H17 game is substantially less favorable to the player. Which game is customary depends on locality. Las Vegas Strip rules are about equally split.
All things being equal, fewer decks are more favorable for the player. (This is true for basic strategy players, even without card counting.) In fact, all things are not equal; multi-deck games almost always have otherwise better rules than single-deck games.
The player may "give up" and get back half his bet, before taking any other action. (In some places, this is posted, "surrender is available", while in other places, it is available, but it is not posted.) In some cases (15 vs. ten, 16 vs. 9, 16 vs. ace), this is slightly favorable. In one important case (16 vs. ten), it is definitely favorable.
(In other words, the option to split exists for a two-card hand from a split the same as the first two cards.) The simplest rule is "resplit infinite"; this means that the player may continue to split so long as he receives same-value cards and is willing to put up the additional bet. More typically, the rule is "resplit to four." These rules are practically identical, since even four hands is fairly unusual.
In general, after splitting aces, the player gets only one card even with the above rule. With this rule in effect, an exception is made: if the second card is an ace, the player can resplit. (This is a favorable rule.)
In other words, the option exists to double for a two-card hand from a split the same as the first two cards. Generally, the player should play a hand after a split the same as the first two cards. However, this rule does slightly change which hands should be split in the first place.
Often called "Reno" rules. (Also seen is "double on 9, 10, or 11 only".) It is annoying to many players because doubling soft hands is considered part of the game.
In some places, the dealer does not receive a hole card, but if the dealer is later found to have blackjack, the player loses only his original bet but not any additional bets (doubles or splits). This has the same advantage as the usual game and it should not be considered "European no-hole-card rule".
In some places, a natural pays 6:5 or even 1:1. This is the most unfavorable variation, increasing the house edge significantly more than any other player restriction.
This is catastrophic to the player, though rarely used in standard Blackjack. It is sometimes seen in "blackjack-like" games.
The player who wishes to take Insurance can bet an amount up to half his original bet. The Insurance bet is placed separately on a special portion of the table, which usually carries the words "Insurance Pays 2:1". The player who is taking Insurance is betting that the dealer was dealt a natural, i.e. a two-card 21 (a blackjack), and this bet by the player pays off 2:1 if it wins. It is called insurance because it, in effect, can protect the original bet if the dealer has a blackjack. If you bet the full half of the original bet, you win the same amount of the player's Blackjack wager. In this case, if insurance is taken and the player doesn't have blackjack but dealer does, no money is lost. Of course the dealer can end up not having blackjack and the player can still win or lose the blackjack bet, and the insurance bet is forfeit.
Insurance is a bad bet for the non-counting player who has no knowledge of the hole card because it has a house edge of 2% to 15%, depending on number of decks used and visible 10-cards . Essentially, taking insurance amounts to betting that the dealer's hole card is a ten or face card. Since in an infinite deck, 4/13 of the cards are tens or face cards, an unbiased insurance wager would actually pay 9:4, or 2.25:1; since the bet only pays 2:1, the house has a strong advantage. However, if the player has been counting cards, he may know that more than a third of the deck is ten-value cards, in which case insurance becomes a good bet.
If a player has a natural (an ace and a ten or face-card) and the dealer is showing an ace, the dealer usually asks the player "Even money?" instead of offering insurance. If the player accepts the offer, he is immediately paid 1:1 for his natural, regardless of whether the dealer has blackjack. Thus, accepting "even money" has exactly the same payout as buying insurance: if the dealer does not have blackjack, the player would forfeit the insurance bet and win 3:2 on the natural, thus receiving a net payout equal to the original bet; if the dealer does have blackjack, the player would push on the natural and win 2:1 on the insurance wager, again receiving a net payout equal to the original bet. Since taking "even money" is equivalent to buying insurance, it is likewise a bad choice for the player, unless he has been counting cards and knows the deck has an unusually high proportion of ten-value cards.
In casinos where a hole card is dealt, a dealer who is showing a card with a value of Ace or 10 may slide the corner of his or her facedown card over a small mirror or electronic sensor on the tabletop in order to check whether he has a natural. This practice minimizes the risk of inadvertently revealing the hole card, which may give the sharp-eyed player a considerable advantage.
|Score||Player buys insurance||Player does not buy insurance|
|Dealer: blackjack |
Player: no blackjack
|Player loses the original bet, but wins 2:1 on his insurance bet, which was 1:2 of the original bet.|
Losses and gains even out to 0.
|Player loses 1:1.|
|Dealer: no blackjack|
|Player wins the original bet, but loses the insurance money.|
The player wins 1:2 of the original bet.
|Player wins 1:1.|
|Dealer: no blackjack|
Player: same as the dealer
|Player loses the insurance money.|
The player loses 1:2 of the original bet.
No loss or gain: 0.
|Dealer: no blackjack|
|Player loses the original bet, and loses the insurance money.|
The player loses 3:2 of the original bet.
|Player loses 1:1.|
|Blackjacks even out, but the player wins 2:1 on the 1:2 of the insurance money.|
The player wins 1:1 of the original bet.
No loss or gain: 0.
|Dealer: no blackjack|
|Player wins the original bet at 3:2, but loses the insurance bet of 1:2.|
The player wins 1:1 of the original bet.
|Player wins 3:2 of the original bet.|
|Your hand||Dealer's face-up card|
Most Las Vegas strip casinos hit on soft 17. This rule change requires a slightly modified basic strategy table -- double on 11 vs A, double on A/7 vs 2, and double on A/8 vs 6. Most casinos outside of Vegas still stand on soft 17.
Basic strategy provides the player with the optimal play for any blackjack situation based on millions of hands played in the long run. However in the short run, as the cards are dealt from the deck, the remaining deck is no longer complete. By keeping track of the cards that have already been played, it is possible to know when the cards remaining in the deck are advantageous for the player.
Card counting creates two opportunities:
Virtually all card counting systems do not require the player to remember which cards have been played. Rather, a point system is established for the cards, and the player keeps track of a simple point count as the cards are played out from the dealer.
Depending on the particular blackjack rules in a given casino, basic strategy reduces the house advantage to near 0 with some single-deck games, and less than one percent in a multi-deck game. Card counting, if done correctly, can give the player an advantage, typically ranging from 0 to 2% over the house. To counter card counting, many casinos switched from a single deck to multiple decks, with the cards dealt out of a container known as a "shoe".
In most US jurisdictions, card counting is legal and is not considered cheating. However, most casinos have the right to ban players, with or without cause, and card counting is frequently used as a justification to ban a player. Usually, the casino host will simply inform the player that he or she is no longer welcome to play at that casino. Players must be careful not to signal the fact that they are counting. The use of electronic or other counting devices is usually illegal.
However, in situations where basic and composition-dependent strategy lead to different actions, the difference in expected value between the two decisions will be small. Additionally, as the number of decks used in a blackjack game rises, both the number of situations where composition determines the correct strategy and the house edge improvement from using a composition-dependent strategy will fall. Using a composition-dependent strategy only reduces house edge by 0.0031% in a six-deck game, less than one tenth the improvement in a single-deck game (0.0387%).
Arnold Snyder's articles in Blackjack Forum magazine brought shuffle tracking to the general public. His book, The Shuffle Tracker's Cookbook, mathematically analyzed the player edge available from shuffle tracking based on the actual size of the tracked slug. Jerry L. Patterson also developed and published a shuffle-tracking method for tracking favorable clumps of cards and cutting them into play and tracking unfavorable clumps of cards and cutting them out of play. Other legal methods of gaining a player advantage at blackjack include a wide variety of techniques for hole carding or gaining information about the next card to be dealt.
Spanish 21 provides players with many liberal blackjack rules, such as doubling down any number of cards (with the option to 'rescue', or surrender only one wager to the house), payout bonuses for five or more card 21s, 6-7-8 21s, 7-7-7 21s, late surrender, and player blackjacks always winning and player 21s always winning, at the cost of having no 10 cards in the deck (though there are jacks, queens, and kings).
21st Century Blackjack (also known as "Vegas Style" Blackjack) is commonly found in many California card rooms. In this form of the game, a player bust does not always result in an automatic loss; there are a handful of situations where the player can still push if the dealer busts as well, provided that the dealer busts with a higher total.
Certain rules changes are employed to create new variant games. These changes, while attracting the novice player, actually increase the house edge in these games. Double Exposure Blackjack is a variant in which the dealer's cards are both face-up. This game increases house edge by paying even money on blackjacks and players losing ties. Double Attack Blackjack has very liberal blackjack rules and the option of increasing one's wager after seeing the dealer's up card. This game is dealt from a Spanish shoe, and blackjacks only pay even money.
The French and German variant "Vingt-et-un" (Twenty-one) and "Siebzehn und Vier" (Seventeen and Four) don't include splitting. An ace can only count as eleven, but two aces count as a Blackjack. This variant is seldom found in casinos, but is more common in private circles and barracks.
Chinese Blackjack is played by many in Asia, having no splitting of cards, but with other card combination regulations.
Another variant is Blackjack Switch, a version of blackjack in which a player is dealt two hands and is allowed to switch cards. For example, if the player is dealt 10-6 and 5-10, then the player can switch two cards to make hands of 10-10 and 6-5. Natural blackjacks are paid 1:1 instead of the standard 3:2, and a dealer 22 is a push.
In Multiple Action Blackjack the player places between 2 or 3 bets on a single hand. The dealer then gets a hand for each bet the player places on a hand. This essentially doubles the number of hands a single dealer can play per hour. Splitting and Doubling are still allowed.
Recently, thanks to the popularity of poker, Elimination Blackjack has begun to gain a following. Elimination Blackjack is a tournament format of blackjack.
Many casinos offer optional side bets at standard blackjack tables. For example, one common side-bet is "Royal Match", in which the player is paid if his first two cards are in the same suit, and receives a higher payout if they are a suited queen and king (and a jackpot payout if both the player and the dealer have a suited queen-king hand). Another increasingly common variant is "21+3," in which the player's two cards and the dealer's up card form a three-card poker hand; players are paid 9 to 1 on a straight, flush or three of a kind. These side bets invariably offer worse odds than well-played blackjack.
In April 2007 a new version of Blackjack, called Three Card Blackjack™ was approved for play in the State of Washington. Three Card Blackjack ™ is played with one deck of 52 cards. In Three Card Blackjack the players place an ante bet. The players and dealer are then dealt 3 cards each. The players make the best blackjack (21) hand they can using 2 or all 3 cards. If the player likes their hand they make a play bet that is equivalent to their ante bet. The dealer must qualify with an 18 or better. If the dealer qualifies and the player beats the dealer, the player is paid 1-1 on both the Ante and Play bets. If the dealer does not qualify, the player is paid 1-1 on their Ante bet and their Play bet pushes. There is no hitting and no busting. At the same time that the player makes the Ante bet, they have the option of making an Ace Plus bet. If the player has 1 Ace in their hand of 3 cards, they get paid 1-1. An Ace and any 10 or Face Card pays them 3-1. An Ace and any two 10's or Face cards is paid 5-1. Two Aces pays 15-1 and Three Aces pays 100-1.
In 2002, professional gamblers around the world were invited to nominate great blackjack players for admission into the Blackjack Hall of Fame. Seven members were inducted in 2002, with new inductees every year afterwards. The physical hall of fame is located at the Barona Casino in San Diego, California. Members include Edward O. Thorp, author of the 1960s book Beat the Dealer which proved that the game could be beaten with a combination of basic strategy and card counting; Ken Uston, who popularized the concept of team play; Arnold Snyder, author and editor of the Blackjack Forum trade journal; Stanford Wong, author and popularizer of the "Wonging" technique of only playing at a positive count, and several others.
Regulation in the United Kingdom