The object of blackjack is simple: to get cards totaling 21, or as close to 21 as possible without going over, and to get a better total than your opponent (the dealer). The cards 2 through 10 count at their face value. Face cards — jack, queen, and king — count as 10, and aces can be counted as 1 or 11. Suits don't matter in blackjack.

Because aces can be counted two ways, hands that contain an ace are called “soft” hands. An ace and a 7, for instance, is a soft 18; if the next card is a 6, you would count the ace as 1 to avoid going over 21. Hands without aces are called “hard” hands; a hard 18 could be a 10 and an 8.

At a casino, your opponent is the dealer. There may be other players at your table, but each of them is playing against the dealer as well. Therefore, unlike poker and many other table games, it's possible for every player at a blackjack table to win the same round. Of course, it's also possible for the dealer to beat every player at the table at once.

Some casinos in Las Vegas still offer single-deck blackjack games, but most casinos today use a minimum of two decks. More common are six-and eight-deck games, which give the house a stronger edge without having to discourage card-counting. Generally, a deck with a high proportion of low cards is considered favorable to the house because the chances of the dealer going bust, or going over 21, are lower. A deck with a high proportion of 10s, face cards, and aces is considered more favorable to the player, in this case because there's a better chance of the dealer drawing a high card and going bust and of the player getting an ace and a 10, for a “natural” blackjack (which pays a bonus).

When a player and a dealer have the same total, it is a “push” or “standoff.” The player doesn't win any money, but she doesn't lose any either. At most tables, a win pays 1:1; so a win on a $5 bet will earn you $5. Although you won't find 10:1 payouts on a natural blackjack these days, most casinos do pay higher for an ace-10 or ace-face card combination.

A true blackjack — an ace paired with a 10, jack, queen, or king — is the highest hand in the game and beats all other combinations of 21. For example, if you have an ace and a 10 and the dealer has three cards that are each a 7, you win. A natural also pays slightly more, usually 3:2. On a $5 bet, that means $7.50 instead of the usual even money.