Bookie: Definition, Meaning, Duties, How They Make Money, and Fee

What Is a Bookie?

A bookie, short or slang for “bookmaker,” is someone who facilitates gambling, most commonly on sporting events. A bookie sets odds, accepts and places bets, and pays out winnings on behalf of other people.

Key Takeaways

  • The term “bookie“ is slang for “bookmaker.“
  • A bookie places bets for customers, usually on sporting events. They also set odds and pay out winnings on behalf of other people.
  • The bookie’s goal is to maintain balance in the books by adjusting the odds as much as possible to maintain an even amount of people betting on a win or loss.

Understanding Bookies

Bookies do not usually make their money by placing bets themselves; rather, they charge a transaction fee on their customers’ bets known as the “vigorish” (“vig” for short). Bookies may also lend money to bettors. A bookie can be an individual or an organization.

Although the term “bookie“ has been associated with illegal activity, with the expansion of sports betting, being a bookmaker has become a legitimate occupation. However, bookmaking and placing bets through a bookmaker can still be illegal. The legality of different types of gambling is largely determined by state governments.

In 2018, the Supreme Court gave states permission to legalize betting on sports if they wish to do so, a landmark ruling that paved the way for bookies to make lots of money without running afoul of the law.

History of Bookies and Sports Betting

Throughout most of the 20th and 21st centuries, sports betting in the U.S. was only completely legal in Nevada, though it was legal in certain forms in Delaware, Montana, and Oregon. As a result, a black market developed for the rest of the country whereby illegal operations of bookies provided opportunities for betting. Some bookies were involved in organized crime, while others operated independently, simply taking bets for a few friends, family members, or colleagues.

However, in 2018, the U.S. Supreme Court struck down the Professional and Amateur Sports Protection Act, which was a federal law preventing states from deciding on their own whether to allow sports betting. The ruling opened the door for its practice throughout the country if states decide in favor of it. Previously, Nevada was the only state to offer comprehensive legal sports betting.

Since that ruling, many states have moved to legalize sports betting. This has prompted record gambling revenues throughout the country with combined revenue from traditional gambling, sports betting, and iGaming amounting to $52.99 billion in 2021, the highest-grossing year ever and an increase of more than 21% from the previous annual record in 2019. According to reporting by Forbes in August 2021, sports betting companies have been announcing a flurry of acquisitions, seeking to capitalize.

$150 billion

The amount the American Gaming Association estimated that Americans illegally wagered on sports each year before the 2018 Supreme Court ruling.

Bookies and Setting the Odds

One of the crucial ways bookies ensure their winnings is by calculating the odds that they will win an event, sometimes by employing teams of statisticians and developing complex models. The terms “lines” (short for “money lines”) and “spreads” (as in “point spreads”) are critical factors for bookies. Sometimes these calculations are based on those developed by casino actuaries or those who deal with risk calculations.

Typically, they underscore which sports team the bookies believe will win a game or match. The lines and spreads can be adjusted in the time leading up to the event based on various bets made in their books and fluctuations in Vegas casino bets. Other unexpected events might impact the odds, such as poor weather, player injuries, and doping scandals.

The bookie’s goal is to maintain balance in the books by adjusting the odds as much as possible so that there’s an even amount of people betting on a win or loss. If the book is balanced, the bookie in effect earns just the vig. However, if there’s a one-sided bet on a particular team or outcome, the bookie takes on an increased risk of losing money.

Gambling always involves a negative expected return—the house always has the advantage. 

Is Being a Bookie Illegal in the U.S.?

No, not necessarily. In 2018, the U.S. Supreme Court opened the door for sports betting throughout the country if states decide in favor of it. Some 33 states have since moved to legalize sports betting, effectively ending the need for bookies to operate illegally in those states. It is still fully illegal in 17 states.

However, that isn’t to say that all bookmakers are law-abiding. Betting is still illegal in some states, and some bookies may prefer to conduct business under the table to avoid facing obstacles and paying taxes.

How Do Bookies Make Money?

Bookies make money by charging a fee on each bet they take, known as the "vigorish" or the "vig,” and pay out money when their customers win a bet. Their goal, understandably, is to make sure that incomings exceed outgoings. That is generally achieved by adjusting the odds so that there’s an even amount of people betting on a win or loss.

How Much Is a Bookie Fee?

The vig that bookies charge is usually in the region of 10%, though it can go higher for high-profile bets, such as a tight line on the Super Bowl.

If you or someone you know has a gambling problem, call the National Problem Gambling Helpline at 1-800-522-4700, or visit to chat with a helpline specialist.

The Bottom Line

The Supreme Court’s 2018 ruling invalidating the Professional and Amateur Sports Protection Act has led to the rapid expansion of sports betting across the U.S., with even family-friendly companies such as Walt Disney getting into the act. This means that the profession of bookmaker no longer needs to be an illegal one, though it still can be in some situations.

Anyone thinking of becoming a bookie, however, would do well to study the considerable requirements of the job first. Many skills are required to achieve success in the field, while losing money at gambling is an all-too-easy accomplishment.

Article Sources
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  1. Legal Information Institute. "Gambling."

  2. Supreme Court of the United States. "Murphy, Governor of New Jersey, et al. v. National Collegiate Athletic Assn. et al.," Pages 30-31.

  3. University of Nevada, Las Vegas, William S. Boyd School of Law. "The Professional and Amateur Sports Protection Act (PASPA): A Bad Bet for the States," Pages 281-282, 288.

  4. Wisconsin Legislated Reference Bureau. "States Are Placing Bets on Sports Betting: Will it Pay Off?" Page 1.

  5. American Gaming Association. "Interactive Map: Sports Betting in the U.S."

  6. American Gaming Association. "AGA Commercial Gaming Revenue Tracker."

  7. Forbes. "U.S. Gambling Revenue to Break $44 Billion Record in 2021."

  8. American Gaming Association. "97% of Expected $10 Billion Wagered on March Madness to Be Bet Illegally."

  9. BossAction. "How to Be a Bookie?"

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