What is a Sportsbook?

A sportsbook is a gambling establishment where you can place a wager on sports events. Typically, they accept bets from individuals who want to wager on either side of a game or event. In the United States, only Nevada and a few other places operated legal sportsbooks until a 2018 Supreme Court decision allowed them to expand into more states.

Each sportsbook has its own rules for betting, but most offer your money back if a bet pushes against the spread (though some count a tie as a loss on parlay tickets). They also set their own odds for each game or event. These can vary from one book to the next, based on things like their internal projections and outside sources such as power rankings and computer algorithms.

In addition to offering bets on individual games, many sportsbooks also take wagers on totals and futures. Futures bets are placed on events that will occur in the future, such as a team winning a championship. These bets are generally available all year round, though their payouts may not come until the end of the season or even the following year.

A good sportsbook will set its odds according to the market. They will adjust these lines as needed, but they’ll always try to balance the action on both sides of a game or event. This is why it’s important to shop around and find the best odds; a difference of a few cents on a Chicago Cubs bet might not break your bankroll right away, but over time it will add up.