Blackjack is one of the most popular casino card games 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 (keeping track of which cards have been played since the last shuffle). Blackjack’s precursor was vingt-et-un (“twenty-one”), which originated in French casinos around 1700, and did not offer the 3:2 bonus for a two-card 21.

When blackjack 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.

Rules

Each player is dealt two cards and is then offered the opportunity to take more. The hand with the highest total wins as long as it doesn’t exceed 21; a hand with a higher total than 21 is said to bust or have too many. Cards 2 through 10 are worth their face value, and face cards (jack, queen, king) are also worth 10. An ace’s value is 11 unless this would cause the player to bust, in which case it is worth 1. A hand in which an ace’s value is counted as 11 is called a soft hand, because it cannot be busted if the player draws another card.

The goal of each player is to beat the dealer by having the higher, unbusted hand. Note that if the player busts he loses, even if the dealer also busts (therefore [tag]Blackjack[/tag] favors the dealer). 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 one player, but still beat the other players in the same round.

 

 

Example of a Blackjack game. The top half of the picture shows the beginning of the round, with bets placed and an initial two cards for each player. The bottom half shows the end of the round, with the associated losses or payoffs.

The minimum 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 his hole card to see if he has blackjack. This check occurs before any of the players play, but after they have been offered [tag]insurance[/tag] (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, [tag]the dealer[/tag] 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 where card counting would otherwise be a viable strategy. The move was decried by longtime blackjack players^[1].

The player’s options for playing his or her hand are:

• Hit: Take another card.
• Stand: Take no more cards.
• Double down: Double the wager, take exactly one more card, and then stand.
• Split: Double the wager and have each card be the first card in a new hand. This option is available only when both cards have the same value.
• Surrender: Forfeit half the bet and give up the hand. Surrender was common during the early- and mid-20th century, but is no longer offered at most casinos.

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.

Some common rules variations include:

• Only one card for split Aces: a single new card is added to each Ace and the turn ends. They are thus regarded as 11-point cards. No other denomination is subject to this process.
• Multiple splits: If a player splits 2 cards and receives a third card of identical value, the hand can be split again, resulting in 3 hands. However, some casinos only allow a single split of the first 2 cards.
• Early surrender: Player has the option to surrender before dealer checks for Blackjack.
• Late surrender: Player has the option to surrender after dealer checks for Blackjack.
• Double-down restrictions: Double-down may only be allowed on certain combinations of cards (usually totaling 9, 10 or 11).
• Double-down after split: Double-down may not be allowed after splitting cards. The split hands are played normally otherwise.
• Split any tens: Players may split any 2 cards which are both worth 10 points, such as a Jack and Queen. This rule is rarely used, since 20 is a very strong hand which is unlikely to be split.
• European No-Hole-Card Rule: the dealer receives only one card, dealt face-up, and does not receive a second card (and thus does not check for blackjack) until players have acted. This means players lose not only their original bet, but also any additional money invested from splitting and doubling down. A game that has no-hole-card doesn’t necessarily mean you will lose additional bets as well as original bets. In Australia for example, a player beaten by a dealer blackjack may keep all split and double bets and lose only the original bet, thus the game plays the same as it would if there were a hole card.

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.

Insurance

If the dealer’s upcard is an Ace, the player is offered the option of taking Insurance before the dealer checks his ‘hole card’.

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 since if the dealer has a blackjack, the bet wins the same amount of the player’s Blackjack wager, such that 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.

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 ^[2]. 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), the dealer usually asks the player “Even money?” This means that instead of winning 3:2 for the natural (which he would only receive if the dealer does not have blackjack), the player with the natural accepts to be paid off at 1:1 regardless of whether the dealer has blackjack. Thus it is exactly the same thing as buying Insurance: If the dealer does not have blackjack, taking “even money” is equivalent to losing the Insurance bet and getting paid 3:2 on the natural; if the dealer does have blackjack, taking “even money” is equivalent to pushing on the original bet and winning 2:1 on the insurance bet.

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 would give the sharp-eyed player a considerable advantage.

Basic strategy

Because blackjack has an element of player choice, players can reduce casino advantage to a small percentage by playing basic strategy. This determines when to hit or to stand, and also determines when to double down or split. Basic strategy is based on the player’s point total and the dealer’s visible card. There are slight variations depending on the house rules and number of decks.

Your hand	Dealer’s face-up card
	2	3	4	5	6	7	8	9	10	A
Hard totals
17-20	S	S	S	S	S	S	S	S	S	S
16	S	S	S	S	S	H	H	SU	SU	SU
15	S	S	S	S	S	H	H	H	SU	H
13-14	S	S	S	S	S	H	H	H	H	H
12	H	H	S	S	S	H	H	H	H	H
11	Dh	Dh	Dh	Dh	Dh	Dh	Dh	Dh	Dh	H
10	Dh	Dh	Dh	Dh	Dh	Dh	Dh	Dh	H	H
9	H	Dh	Dh	Dh	Dh	H	H	H	H	H
5-8	H	H	H	H	H	H	H	H	H	H
Soft totals
	2	3	4	5	6	7	8	9	10	A
A,8 A,9	S	S	S	S	S	S	S	S	S	S
A,7	S	Ds	Ds	Ds	Ds	S	S	H	H	H
A,6	H	Dh	Dh	Dh	Dh	H	H	H	H	H
A,4 A,5	H	H	Dh	Dh	Dh	H	H	H	H	H
A,2 A,3	H	H	H	Dh	Dh	H	H	H	H	H
Pairs
	2	3	4	5	6	7	8	9	10	A
A,A	SP	SP	SP	SP	SP	SP	SP	SP	SP	SP
10,10	S	S	S	S	S	S	S	S	S	S
9,9	SP	SP	SP	SP	SP	S	SP	SP	S	S
8,8	SP	SP	SP	SP	SP	SP	SP	SP	SP	SP
7,7	SP	SP	SP	SP	SP	SP	H	H	H	H
6,6	SP	SP	SP	SP	SP	H	H	H	H	H
5,5	Dh	Dh	Dh	Dh	Dh	Dh	Dh	Dh	H	H
4,4	H	H	H	SP	SP	H	H	H	H	H
2,2 3,3	SP	SP	SP	SP	SP	SP	H	H	H	H

The above is a basic strategy table for 3 or more decks, dealer stands on soft 17, double on any 2 cards, double after split allowed, dealer peeks for blackjack, and blackjack pays 3:2. Key:

S = Stand

H = Hit

Dh = Double (if not allowed then hit)

Ds = Double (if not allowed then stand)

SP = Split

SU = Surrender (if not allowed, then hit)

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.

“Gamble” redirects here. For other uses, see Gamble (disambiguation).

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The term gambling has had many different meanings depending on the cultural and historical context in which it is used. Currently, in Western societies, it has an economic definition, referring to “wagering money or something of material value on an event with an uncertain outcome with the primary intent of winning additional money and/or material goods”. Typically the outcome of the wager is evident within a short period of time.

The term gaming in this context typically refers to instances in which the activity has been specifically permitted by law. The two words are not mutually exclusive; i.e.: a “gaming” company offers (legal) “gambling” activities to the public.

Legal aspects

Because many religious authorities generally disapprove of gambling to some extent, and because gambling can have adverse social consequences, most legal jurisdictions limit gambling to some extent. Some Islamic nations prohibit gambling; most other countries regulate it.^[3]

Many jurisdictions, local as well as national, either ban or heavily control (by licensing) gambling. Such regulation generally leads to gambling tourism and illegal gambling. The involvement of governments, through regulation and taxation, has led to a close connection between many governments and gaming organizations, where legal gambling provides significant government revenue, such as in Monaco or Macau.

Under US federal law, gambling is legal in the United States, and states are free to regulate or prohibit the practice. Gambling has been legal in Nevada since 1931, forming the backbone of the state’s economy, and the city of Las Vegas is perhaps the best known gambling destination in the world. In 1976, gambling was legalized in Atlantic City, New Jersey, and in 1990, it was legalized in Tunica, Mississippi; both of those cities have developed extensive casino and resort areas since then. Since a favorable US Supreme Court decision in 1987, many Native American tribes have built their own casinos on tribal lands as a way to provide revenue for the tribe. Because the tribes are considered sovereign nations, they are often exempt from state laws banning gambling, and are instead regulated under federal law.

Because contracts of insurance have many features in common with wagers, insurance contracts are often distinguished under law as agreements in which either party has an interest in the “bet-upon” outcome beyond the specific financial terms. E.g.: a “bet” with an insurer on whether one’s house will burn down is not gambling, but rather insurance — as the homeowner has an obvious interest in the continued existence of his/her home independent of the purely financial aspects of the “bet” (i.e., the insurance policy).

There is generally legislation requiring that the odds in gaming devices are statistically random, to prevent manufacturers from making some high-payoff results impossible. Since these high-payoffs have very low probability, a house bias can quite easily be missed unless checking the odds carefully.^[4]

Gambling variables

There are three variables common to all forms of gambling:

• How much is being wagered, the initial stake (in money or material goods).
• The predictability of the event.
  • In mechanical or electronic gambling such as lotteries, slot machines and bingo, the results are random and unpredictable; no amount of skill or knowledge (assuming machinery is functioning as intended) can give an advantage in predictability to anyone.
  • However, for sports events such as horse racing and soccer matches there is some predictability to the outcome; thus a person with greater knowledge and/or skill will have an advantage over others.
• The odds agreed between the two (or more) parties to the wager; where there is a house or a bookmaker, the odds are (quite legally) arranged in favour of the house.

The expected value, positive or negative, is a mathematical calculation using these three variables. The amount wagered determines the scale of an individual wager (bet); the odds and the amount wagered determine the payout if successful; the predictability determines the frequency of success. Finally the frequency of success times the payout minus the amount wagered equals the “expected value” The skill of a gambler lies in understanding and maneuvering the three variables so that the “actual value” is positive over a series of wagers.

Blackjack.

Types of gambling

Casino games

While almost any game can be played for money, and any game typically played for money can also be played just for fun, some games are generally offered in a casino setting.

“Beatable” casino games

A highly skilled player with a well-designed strategy can create a positive mathematical expectation on games such as:

• Blackjack—with card counting unless a continuous shuffler is used
• Pai Gow Poker and Tiles—player-dealt
• Parimutuel betting
• Poker (Also recognized as a game of skill)
• Slot machines—where progressive jackpots or bonuses reach a certain break-even point
• Sports betting
• Video poker—with proper pay table and/or progressive jackpot

“Unbeatable” casino games

A pachinko parlor in Tokyo, Japan.

These games have a negative expectation regardless of how few or many games someone plays. Nevertheless, this does not stop gamblers from having false beliefs (the “gambler’s fallacy”) that their actions or “way of playing” will influence the outcome.

• Baccarat (punto banco)
• Caribbean Stud Poker
• Casino war
• Craps (though some believe the use of dice control can beat the game)
• Fan-Tan
• Faro
• Keno
• Let it ride
• Pachinko
• Pyramid Poker
• 3-card poker
• 4-card poker
• Red Dog
• Roulette
• Sic Bo
• Spanish 21—without counting
• Texas Hold’em Bonus Poker

Non-casino gambling games

Mahjong tiles.

Gambling games that take place outside of casinos include Bingo (as played in the US and UK), dead pool, lotteries, pull-tab games and scratchcards, and Mahjong.

Other non-casino gambling games include:

• Card games, such as Liar’s poker, Bridge, Basset, Lansquenet, Piquet, Put, Teen patti
• Coin-tossing games such as Head and Tail, Two-up
• Confidence tricks such as Three-card Monte or the Shell game
• Carnival Games such as The Razzle or Hanky Pank
• Dice-based games, such as Backgammon, Liar’s dice, Passe-dix, Hazard, Threes, Pig, or Mexico

Fixed-odds gambling

Fixed-odds gambling and Parimutuel betting frequently occur at many types of sporting events. In addition many bookmakers offer fixed odds on a number of non-sports related outcomes, for example the direction and extent of movement of various financial indices, the winner of television competitions such as Big Brother, election results,^[5]. Interactive prediction markets also offer trading on these outcomes, with “shares” of results trading on an open market.

Parimutuel betting

Tokyo Racecourse in Tokyo, Japan.

Main article: Parimutuel betting

One of the most widespread forms of gambling involves betting on horse or greyhound racing. Wagering may take place through parimutuel pools; or bookmakers may take bets personally. Parimutuel wagers pay off at prices determined by support in the wagering pools, while bookmakers pay off either at the odds offered at the time of accepting the bet; or at the median odds offered by track bookmakers at the time the race started.

Sports betting

Main article: sports betting

Betting on team sports has become an important service industry in many countries. For example, millions of Britons play the football pools every week.

Arbitrage betting

Main article: arbitrage betting

Arbitrage betting is a theoretically risk-free betting system in which every outcome of an event is bet upon so that a known profit will be made by the bettor upon completion of the event, regardless of the outcome. Arbitrage betting is a combination of the ancient art of arbitrage trading and gambling, which has been made possible the large numbers of bookmakers in the marketplace, creating occasional opportunities for arbitrage.

Other types of betting

One can also bet with another person that a statement is true or false, or that a specified event will happen (a “back bet”) or will not happen (a “lay bet”) within a specified time. This occurs in particular when two people have opposing but strongly-held views on truth or events. Not only do the parties hope to gain from the bet, they place the bet also to demonstrate their certainty about the issue. Some means of determining the issue at stake must exist. Sometimes the amount bet remains nominal, demonstrating the outcome as one of principle rather than of financial importance.

Betting exchanges allow consumers to both back and lay at odds of their choice. Similar in some ways to a stock exchange, a better may want to back a horse (hoping it to win) or lay a horse (hoping it to lose, effectively acting as bookmaker)

Staking systems

Main article: betting strategy

Many betting systems have been created in an attempt to “beat the bookie” but most still accept that no system can make an unprofitable bet profitable over time. Widely-used systems include:

• Fixed stakes – a traditional system of staking the same amount on each selection.
• Fixed profits – the stakes vary based on the odds to ensure the same profit from each winning selection.
• Due-column betting – A variation on fixed profits betting in which the bettor sets a target profit and then calculates a bet size that will make this profit, adding any losses to the target.
• Kelly – the optimium level to bet to maximize your future median bank level.
• Martingale – A system based on staking enough each time to recover losses from previous bet(s) until one wins.

Other uses of the term “gambling”

Many risk-return choices are sometimes referred to colloquially as “gambling.” Whether this terminology is acceptable is a matter of debate, but generally the following activities are not considered gambling:

• Emotional or physical risk-taking, where the risk-return ratio is not quantifiable (e.g., skydiving, campaigning for political office, asking someone for a date, etc.)
• Insurance is a method of shifting risk from one party to another. Insurers use actuarial methods to calculate appropriate premiums, which could be considered similar to calculating gambling odds. However, insurers can set their premiums to obtain a long term positive expected return.
• Situations where the possible return is a secondary reason for the wager/purchase (e.g., buying a raffle ticket to support a charitable cause)

Investments are also usually not considered gambling, although some investments can involve significant risk. Examples of investments include stocks, bonds and real estate. Starting a business can also be considered a form of investment. Investments are generally not considered gambling when they meet the following criteria:

• Positive expected returns (at least in the long term)
• Economic utility
• Underlying value independent of the risk being undertaken

Some speculative investment activities are particularly risky, but are still usually considered separately from gambling:

• Securities derivatives, such as options or futures, where the value of the derivative is dependent on the value of the underlying asset at a specific point in time (typically the derivative’s associated expiration date)
• Foreign currency exchange (forex) transactions
• Prediction markets