Blackjack is a card game played on a semicircular table by two or more players with a dealer. The dealer has a face-down card and a hole card and must follow specific rules in making playing decisions. The objective of the game is to get a hand value closer to 21 than the dealer without going over. Unlike other card games, the actions of other players at the table are not relevant to your own hand, as you are competing only against the dealer’s hand.

To win, your starting hand must be an Ace and a card valued 10 or higher. This is called a blackjack or “natural,” and it beats all hands other than another natural. The player with the highest total wins.

Before you play, place your chips in the betting areas marked on the table. After all players have placed their bets, the dealer will reveal his or her card and hit or stand according to predetermined rules.

The house edge is a factor that determines the cost of playing blackjack. It can vary depending on the number of decks in play and the rules of the game. To minimize the house edge, you should learn basic strategy and avoid making unnecessary risks.

Using probability theory, you can determine the probability of a particular outcome in blackjack. This includes the probability of getting a certain total, as well as the probabilities of hitting or standing. However, it is important to remember that these probabilities are conditional and can change with every new card dealt. This means that you must always evaluate your chances based on the current state of the game.

In blackjack, it is important to understand that the house edge is a mathematically calculated estimate of the amount that the casino expects to lose on each bet made by a player. This is determined by adding up the probabilities of each possible outcome, as well as the expected return on the investment (EV). To calculate EV, you must know the probability of winning, the payout rate and the probability of losing.

A player can minimize the house edge by using a card counting system. A successful count requires identifying and memorizing the cards that are most likely to appear in the deck at a given moment. This requires an ability to process large amounts of information at a fast pace, and it requires extensive practice to master.

Some casinos reduce the 3 to 2 payout for blackjacks to 6 to 5. This is a significant increase in the house edge, and it makes any card counting strategy useless.

Hitting when the dealer has a 4 is risky because there’s a high chance that you will bust. Choosing to stand, on the other hand, will give you only a 22% chance of winning against the dealer’s blackjack. That’s a pretty lousy way to play blackjack.