A sportsbook is a gambling establishment that takes bets on different sporting events. It pays winners based on their predictions of the outcome and keeps the stakes of those who don’t win. In the United States, sportsbooks were once legally operated only in Nevada (and in limited forms in Montana, Oregon and Delaware) but are now available in more than 20 states, including those that have legalized online sports betting.

A major part of a sportsbook’s success is making sure the odds it offers are fair. To do this, it sets odds that differ from the true probability of an event occurring. These differences are known as “vig” or vigorish. Sportsbooks also mitigate the risk they will lose money by taking other wagers that offset those placed on their own book.

Betting options vary by state, and new concepts in sportsbooks are opening up all the time. The key is to find a sportsbook that fits your preferences and budget. Check to make sure the sportsbooks you are considering have large menus of different sports, leagues and events and offer a variety of bet types and competitive odds.

Some of the newer sportsbooks have taken a fresh look at responsible gambling and are tying it more closely to customer relationship management. For instance, FanDuel will adjust the marketing messages and push notifications customers receive if they have shown early signs of problem gambling. The company is also exploring ways to reward responsible bettors with merchandise.