Blackjack, originally vingt-et-un (“twenty one” in French), also known as twenty-one, 21 and pontoon, is the most popular traditional card game in casinos worldwide. Blackjack draws such huge popularity from the unique combination of luck, skill, decision making, and the publicity that surrounds card counting (see blackjack card counting), where players have the ability to turn the odds of the game in their favor by making strategic decisions and bets according to cards that are known (having been dealt) and making educated guesses on the cards that are unknown (still in the ‘shoe’). Casinos are always on the lookout for players that are suspected of card counting, which is an art that is difficult to master yet easy practice at a low level.

In blackjack, players place bets against the casino dealer and do not play against each other (for head-to-head blackjack tournaments see blackjack tournaments). The objective is to reach a point total that is higher than the dealer’s without busting (going over 21). Cards are measured at face values from 2 to 10, royal cards (Jack, Queen, King) are counted as 10 and Aces have values of 1 or 11, depending on the hand. If the player's and the dealer's point totals are the same at the end of the round, the hands are tied and the round is a ‘push’ or ‘stand off’ and the player’s initial bet is returned.
After the player places an initial bet the dealer deals the cards from the deck (if it’s a single-deck or two-deck game) or from the shoe (if there are 4, 6, or 8 decks). Two cards are dealt to the player and two cards are dealt to the dealer. The proper deal is first card to the player, second card to the dealer (face down – ‘hole card’), third card to the player and fourth card to the dealer – face up (in European blackjack the dealer initially deals himself only one card. The second card is dealt only when the players have finished playing their hands). Players’ cards are usually dealt face up. Some casinos have policies of dealing cards face down. After dealing initial cards, if any player has a Blackjack (‘natural’ 21, which is an Ace with any 10-valued card), he is usually paid x1.5 times his initial bet (that is the 3:2 ratio) for his bet, unless the dealer also has Blackjack, in which case there’s a tie (push). If the dealer’s up card is an Ace, a player with Blackjack is asked if he wants ‘Even Money’, which means he gets paid 1:1 on his bet. If the player rejects even money he risks tying with the dealer and hopes the dealer doesn’t have Blackjack so he will receive 3:2 on his bet. If the dealer has a Blackjack and none of the other players have Blackjacks they all lose immediately and don’t get a chance to improve their hands (there are exceptions to this depending on the casino’s blackjack rules. see also Blackjack basics rules).

If the dealer does not have a Blackjack, then each player in turn has an option of asking for more cards (which is called ‘hitting’) or staying with his current card total (which is called ‘holding’ or ‘standing’). Each player can hit as much as he wants unless he goes over 21 and busts. Furthermore, depending on the player’s cards and the casino’s blackjack table rules, the player can make additional decisions and plays such as Double (doubling his initial bet and receiving one card only), Split (with two identically valued initial cards, or depending on the table rules, a player can add another bet and split the hand into two separate hands and receive one additional card to each of the split hands and play each hand separately), and Surrender (yield the hand before making any decision and losing half the initial bet). If the player busts he immediately loses his bet.

Once all players have finished making their decisions the dealer reveals his hole card and, according to the blackjack table rules, draws additional cards or stands. The dealer doesn’t choose whether to hit or stand, and is bound by the rules of the table such as ‘Hit on Soft 17’ (which means there’s an Ace in his hand that can be considered as 1 or 11) or ‘Stand On All 17’s’ (in Atlantic City, for example, all dealers must stand on all 17’s). In any case if the dealer has less than a point total of 16 he must draw another card. If the dealer busts, then all the players still in the round win immediately. Bets are commonly paid out at ratios of 1:1.