BLACK JACK

Blackjack, also known as twenty-one, is the most widely played casino banking game in the world.[1] Blackjack is a comparing card game between a player and dealer, meaning players compete against the dealer but not against other players. It is played with one or more decks of 52 cards. The objective of the game is to beat the dealer in one of the following ways:
* Get 21 points on the player's first two cards (called a "blackjack" or "natural"), without a dealer blackjack;
* Reach a final score higher than the dealer without exceeding 21; or
* Let the dealer draw additional cards until his or her hand exceeds 21.
The player or players are dealt a two-card hand and add together the value of their cards. Face cards (kings, queens, and jacks) are counted as ten points. A player and the dealer can count an ace as 1 point or 11 points. All other cards are counted as the numeric value shown on the card. After receiving their first two cards, players have the option of getting a "hit", or taking an additional card. In a given round, the player or the dealer wins by having a score of 21 or by having the higher score that is less than 21. Scoring higher than 21 (called "busting" or "going bust") results in a loss. A player may win by having any final score equal to or less than 21 if the dealer busts. If a player holds an ace valued as 11, the hand is called "soft", meaning that the player cannot go bust by taking an additional card; 11 plus the value of any other card will always be less than or equal to 21. Otherwise, the hand is "hard".
The dealer must hit until the cards total 17 or more points. (At many tables the dealer also hits on a "soft" 17, i.e. a hand containing an ace and one or more other cards totaling six.) Players win by not busting and having a total higher than the dealer's. The dealer loses by busting or having a lesser hand than the player who has not busted. If the player and dealer have the same total, this is called a "push", and the player typically does not win or lose money on that hand. If all available players bust, the hand ends automatically without the dealer having to play his or her hand.
Blackjack has many rule variations. Since the 1960s, blackjack has been a high-profile target of advantage players, particularly card counters, who track the profile of cards that have been dealt and adapt their wagers and playing strategies accordingly.
Blackjack has inspired other casino games, including Spanish 21 and pontoon. The recreational British card game of black jack is a shedding-type game and unrelated to the subject of this article.

SPANISH BLACK JACK
Spanish 21 is played on a blackjack table with a custom layout [1] and uses the following rules:
* The game is played with six or eight decks dealt from a shoe, or from a continuous shuffling machine (CSM). Spanish 21 is played with 48-card Spanish decks, which are standard 52-card decks with the 4 ten-spot cards removed. All cards have the same values as in blackjack.
* The dealer gets a hole card.
* Like traditional blackjack, the dealer hits on 16 and stands on 17. In some venues, the dealer hits on a hard 17 (abbreviated as H17), though most venues have the dealer stand on soft 17 (S17). Hitting soft 17 (H17) negatively impacts the player; that rule increased the house edge by 0.40%.
* Blackjack (a natural total of 21 on the first two cards) always wins, and is always paid 3:2 regardless of whether or not the dealer has a blackjack.
* Insurance is paid 2:1, just like in blackjack, despite the fact that there are four fewer ten-valued cards per deck. As 3 cards in 12 are worth ten, the chance of the dealer getting a blackjack when showing an Ace is only 25%. Therefore, for insurance to be an even bet, it would have to pay 3:1, not 2:1. The house edge on the insurance is 24.7%, one of the worst of any wager in a casino.
* Hitting, standing, and splitting all follow similar rules to blackjack. Doubling after splitting (DAS) is always permitted, and, in most venues, players are allowed to draw as many cards as they wish after splitting aces, or may double down after receiving second or subsequent cards.
* Players can split to a maximum of four hands, even on aces.
* In most venues, if the dealer does not have blackjack, players may surrender, and get half their bet back in exchange for relinquishing the right to play on. This type of surrender is known as a "late surrender" (LS).
* Players can surrender after doubling (sometimes called forfeit, double-down rescue, or concede). The dealer takes the original bet, and the player retains the double portion of the bet. This is because the player is allowed to double down for less than the original bet.
* Once the initial two-card hands are dealt, if the dealer is showing an Ace or face card, he peeks underneath the hole card to check for a blackjack, before playing actually commences. If he has blackjack, all players automatically lose, unless they also have a blackjack (which, as mentioned above, automatically win 3:2).
* The player may double down on any total and on any number of cards.
* In some casinos, players may double double down, or redouble up to two times after doubling down. For example: The player bets one unit and is dealt 2-3, giving a hand total of 5; the dealer is showing a 6. The player doubles the first time and draws a 3. The hand total is now 8 and the total amount wagered is two units. The player doubles a second time and draws a 3. The hand total is now 11 and the total amount wagered is four units. When the player doubles a third time on 11, the total amount wagered will be eight units. Redoubling is a profoundly player-advantageous rule, when optimally executed.
* A total of 21 always wins for the player. It never pushes against the dealer's 21.
* A five-card 21 pays 3:2, a six-card 21 pays 2:1, and a 21 with seven or more cards pays 3:1. A 21 composed of 6-7-8 or 7-7-7 of mixed suits pays 3:2, of the same suit pays 2:1, and of spades pays 3:1. These bonus payouts apply even if the hand was the result of a split. However, doubling down negates these bonuses.
* A "super bonus" of $1000 for bets under $25, and $5000 for bets of $25 and over, is paid on a suited 7-7-7 against any dealer 7. All other players at the table receive a $50 "envy bonus". Splitting or doubling down negates the "super bonus".
The removal of the four tens in each deck gives roughly a 2% advantage to the dealer. The liberal rules of Spanish 21, though, do compensate for this. With optimal play, the house edge of a Spanish 21 table is lower than that of a blackjack table with the same rules on hitting or standing on soft 17.
The game also offers an optional "Match the Dealer" side bet, which compares a player's cards with the dealer's upcard. Matching the rank of the dealer's card pays 4:1 on a six-deck game, and 3:1 on an eight-deck game, while a "perfect match" of rank and suit pays 9:1 on six decks and 12:1 on eight decks. A player may win on both cards; (e.g. if a player has 8s 8c and the dealer has 8c as an upcard, the player will receive 3:1 on the rank match and 12:1 on the perfect match, paying out a total of 15:1.) While this side bet has a house edge of approximately 3%, significantly higher than the edge of the main game, it is one of the lowest house edges of any blackjack side bet.