Blackjack is a casino card game that involves beating the dealer to win. The player and dealer are each dealt two cards, which must add up to a total of 21 or higher. The face cards (Jacks, Queens and Kings) count as 10 while the Aces count as either 1 or 11.

The objective of the game is to beat the dealer’s hand without going over 21. It is common for players to make side wagers, which are separate from the main blackjack wager. Typically, the player must place a wager on blackjack to qualify for any side bet. Some games require that a player’s blackjack wager equal or exceed any side bet wager.

While it may seem that luck plays a large role in blackjack, it is actually a game of math and statistics. There are certain mathematical principles that, if followed correctly, can reduce the house edge. A knowledgeable player will be able to tell whether it is wise to take another card, increase the amount of their bet or stop playing altogether.

There are a number of different strategies for winning blackjack, but the most basic is to simply beat the dealer. This can be done by having a hand with an ace and a card valued at 10 or by getting a blackjack. The best way to do this is by maximizing the number of cards in your hand.

Several rule changes have been made to the game over time, but most of them decrease the player’s advantage. These include allowing players to split and double down with all cards, swapping cards between wagered hands, and surrendering undesirable two-card hands. Most of these rule changes were designed to counteract the advantages of card counting, which is an advanced strategy that allows players to track the concentration of high-value cards in a deck and adjust their bets accordingly.

In addition, some casinos change the rules of the game to increase the house edge. For example, some casinos pay 6 to 5 for blackjack instead of the normal 3 to 2 payout. This changes the basic strategy of many players and increases the house edge by 1.4 percent.

Some casinos also allow players to purchase insurance. In this case, the dealer will check their hole card before deciding on action. If the dealer has a blackjack, they will sweep the original wagers on the table and pay any insurance bets at a rate of 2:1. Otherwise, they will play their own hand and the game will proceed normally.

While some players may find this practice appealing, it is important to remember that the dealer has a much bigger advantage in the game. The dealer acts last and can see the entire stack of cards before anyone else, which gives them a significant advantage over their opponents. This advantage is even greater when the cards are shuffled frequently. This is because the cards are taken from a shoe filled with multiple decks and then run through a second shoe, creating a new stack of cards that are more difficult to count.