Bookmakers, or bookies, are organizations or individuals that take bets on sporting events or other types of events based on odds which are agreed upon prior to the bets being made. While sports betting is generally considered to be illegal in the United States, the rest of the world participates with a fairly high percentage of regularity. In the UK in particular these bookmakers can be used to place bets on a wide variety of events, ranging from football betting to sports betting on all types of sports, as well as random one-time events such as whether or not it will snow for Christmas or whether a certain individual will be elected mayor in a certain town, or so on and so forth.

Bookmakers rely on mathematics to determine the odds of a particular event. Generally, bookmakers will adjust the odds in their favour by having a point spread, with the overall goal of guaranteeing a profit for their organization by achieving what is known as a balanced book. A bookmaker generally does not attempt to profit from the bets themselves, but rather makes money from the event regardless of the outcome using a complex series of sports betting procedures, such as betting an equal number of bets for each outcome, or by arranging for the amounts wagered on a particular outcome to reflect the odds themselves. Bookmakers are an integral part of sports betting as a whole, and are part of the fun when it comes to gambling.