Quick Answer: A sportsbook is a venue where a gambler can place wagers on sporting events, such as golf, football, basketball, baseball, ice hockey, soccer, horse racing, greyhound racing, boxing, and mixed martial arts. The method of betting varies with the sport and the type of game. In the US, the Professional and Amateur Sports Protection Act of 1992 allowed only Nevada, Oregon, Montana, and Delaware to legally wager on sports other than horse racing, greyhound racing, and jai alai; the law was ruled unconstitutional on May 14, 2018, freeing states to legalize sports betting at their discretion. Winning bets are paid when the event finishes, or if not finished, when played long enough to become official; otherwise, all bets are returned. This policy can cause some confusion since there can be a difference between what the sportsbook considers official and what the sports league consider official. Customers should carefully read the sportsbook rules before placing their bets.