How Does Sports Betting Work? Odds, Parlays, and Betting Apps

Sports betting is no longer limited to casinos or trips to Las Vegas. Today, a person can place a bet on a phone in seconds. Betting ads, odds, and promotions may appear during games, on social media, and in group chats.

This article explains common sports betting terms, including parlays, prop bets, live betting, odds, promotions, and betting apps. It also looks at why betting can begin to feel like a normal part of being a sports fan and what parents should know.

Your family is watching a football game when your teen says, “If he scores one more touchdown, my friend wins $200.”

You look over. “Your friend bet $200?”

“No,” your teen says. “He only bet $10. It’s a parlay.”

A few minutes later, an ad offers a “no-sweat” bet. The announcers discuss the latest odds. Your teen checks a phone and says the odds just changed.

If all of this feels like a new language, you are not alone. Sports betting has changed quickly. Understanding how it works can help you talk with your child about it.

Sports betting is now a very large business. In 2025, people legally wagered about $167 billion through state-regulated commercial sportsbooks in the United States. That comes to about $457 million in bets each day. Illegal platforms would increase these numbers significantly.

By early 2026, some form of sports betting had been legalized in 39 states and Washington, D.C. Rules about online betting, legal age, and allowed sports vary by state. See state-by-state information here.

You may picture sports betting as choosing which team will win a game. That is still one kind of bet. But today, people can bet on almost every part of a sporting event.

For example, someone may bet on:

• Which team will win
• How many points a team will score
• How many yards a player will gain
• Who will score first
• What will happen in the next few minutes
• Several game results bundled into one bet

A person can place bets before a game or while it is being played. Some apps allow people to bet on several sports, leagues, and events around the world at the same time.

People can bet on games and events taking place around the world. Depending on the app and state rules, betting choices may include:

• Soccer in England, Spain, Italy, and other countries
• World Cup and Olympic events
• International tennis and golf
• Cricket in India, Australia, and other countries
• Formula 1 racing
• Rugby
• Boxing and mixed martial arts
• Table tennis, darts, and other less familiar sports
• Some esports and video game contests

This means betting opportunities may be available almost around the clock. A young person might bet on an NFL game at night, a soccer match in Europe the next morning, and a tennis match in another time zone later that day.

They may know little about the teams or players. The app may still offer statistics, suggested bets, and promotions that make the event seem like a good betting opportunity.

For example:

A young adult loses a basketball bet at 10 p.m. Instead of stopping, they see that a soccer match in another country is about to begin. They place another bet, hoping to win back the money they lost. By the next morning, several more international events are available.

Easy access to sports around the world can make it harder to reach a natural stopping point. There is almost always another game, match, race, or tournament starting somewhere.

What do the odds mean?

Odds tell you two things:

1. Which outcome the sportsbook thinks is more or less likely
2. How much a winning bet will pay

In the United States, odds often have a plus or minus sign. The easiest way to understand them is to use $100 as the starting point.

Plus odds: How much you could win on a $100 bet

Imagine that the Tigers are listed at +150.

If you bet $100 and the Tigers win:

• You get your original $100 back.
• You also win $150.
• You receive $250 total.

The $150 is your profit. The $250 is the full amount returned to you.

Plus odds are often used for the underdog—the team considered less likely to win.

Minus odds: How much you must bet to win $100

Now imagine that the Lions are listed at –150.

To win $100 in profit, you must bet $150.

If the Lions win:

• You get your original $150 back.
• You also win $100.
• You receive $250 total.

Minus odds are often used for the favorite, meaning the team considered more likely to win.

Here is the quick version:

• +150 means a $100 bet could win $150 in profit.
• –150 means you must bet $150 to win $100 in profit.

Most apps do the math and show the possible payout before a person places a bet. This can make betting feel easy, even if the person does not fully understand the odds.

Odds can also make betting seem like a math problem that a knowledgeable fan can solve. But odds are not promises. An injury, a bad call, the weather, or one unexpected play can change the outcome.

Sportsbooks also build an advantage into their odds. People may win individual bets, but the business is set up to make money over time.

What is a parlay?

A parlay combines two or more bets into one larger bet. Every part of the parlay, also known as a “leg”, usually has to win for the person to get paid.

Imagine that a young adult places this four-part parlay:

• The home team will win.
• The quarterback will throw at least two touchdowns.
• One player will gain more than 75 yards.
• Both teams together will score more than 45 points.

The app says a $10 bet could win $200. That large possible win makes the parlay exciting.

But there is a catch. If the first three picks are right and the teams score only 44 points, the whole parlay loses.

Adding more picks can increase the possible payout. It also adds more ways to lose. Sportsbooks often highlight parlays because these bets can be very profitable for the company.

What is a prop bet?

A proposition bet, or prop bet, is a bet on something that happens within a game. It does not always depend on which team wins.

Examples include:

• Will a certain player score a touchdown?
• Will a basketball player make more than three three-point shots?
• Will a quarterback throw for more than 250.5 yards?
• Which player will score first?

Here is what “more than 250.5 yards” means: The quarterback must throw for at least 251 yards for that bet to win. Sportsbooks use the half yard so there cannot be a tie.

Prop bets can make every player and every play feel like a betting chance. A fan may stop focusing on whether the team wins and start worrying about whether one player catches one more pass.

Prop bets may also create pressure for players. The NCAA has raised concerns about certain player-based bets because college athletes may face threats or harassment when someone’s bets.

What is live betting?

Live betting, also called in-game betting, happens after the game begins. The app changes the odds as the action unfolds.

Suppose a favored basketball team falls behind in the first quarter. The app may quickly offer new odds on whether that team will come back.

A few minutes later, the app may offer more choices:

• Will the next score be a two-point or three-point shot?
• Will the teams score more than 25 points this quarter?
• Will a player make the next free throw?

This speed matters. There may be little time to stop, think, or notice how much money has already been spent.

Imagine that a young adult loses $20 during the first half. They think, “I can win it back in the second half.” They place another bet, lose again, and then bet on the next game.

Trying to win back lost money is called chasing losses. It can turn one disappointing bet into a much bigger problem.

Sportsbooks use promotions to get people to open an account or keep betting. These offers may sound like free money or an easy way to lower the risk.

The details are often more complicated.

A deposit match

The sportsbook adds bonus funds based on how much money a person deposits.

For example, an app may offer a “100% deposit match up to $100.” If someone deposits $50, the app may add $50 in bonus funds.

That does not always mean the person can withdraw $100 right away. They may have to bet the money one or more times before they can withdraw any winnings. The bonus may also expire.

A profit boost

A profit boost increases the amount a person can win on one bet.

For example, a $10 bet might normally earn $20 in profit. With a 25% profit boost, it could earn $25 instead.

The boost may apply only to certain games or kinds of bets. There may also be a limit on how much a person can bet. The offer is meant to make the bet feel more valuable and harder to pass up.

A “no-sweat” or “second-chance” bet

This offer promises something back if a bet loses.

For example, someone places a $20 “no-sweat” bet and loses. The sportsbook may give them a $20 bonus bet.

However, the person usually does not get the original $20 back as cash. They get credit that must be used to place another bet. That means the offer can lead to more betting instead of truly removing the risk.

Special odds for a popular game

A sportsbook may offer better odds on a big game to make a bet look more appealing.

For example, a team might normally have odds of +150. The app may raise the odds to +200 for a limited time.

On a $10 bet:

• Odds of +150 would offer $15 in possible profit.
• Odds of +200 would offer $20 in possible profit.

These promotions often have limits. The better odds may apply only to new customers, small bets, or a certain kind of wager.

Rewards for placing several bets

Some apps offer a reward after a person places a set number of bets.

For example:
“Place one bet each day for five days and earn a $25 bonus bet.”

The reward may encourage someone to bet on days when they had not planned to gamble. They might spend $50 or more trying to earn a $25 bonus that cannot be withdrawn as cash.

These offers may be called rewards, challenges, missions, streaks, or loyalty programs. Whatever the name, the goal is often the same: to keep the person returning to the app and betting more often.

What to check before accepting a promotion

Look for:

• How much money must be deposited or bet
• Whether the reward is cash or betting credit
• When the offer expires
• Which bets qualify
• The largest bet allowed
• Whether the person must bet several times to use the reward

A useful question to consider is:

“Does this offer save you money, or is it trying to get you to bet more than you planned?”

A betting app puts a sportsbook in a person’s pocket all day. A person does not need to drive anywhere, carry cash, or wait for the next game.

Apps may include:

• Fast deposits
• Live odds that change during games
• Alerts about new bets
• Personalized promotions
• Bright graphics or celebrations after a win
• Easy ways to repeat a bet
• Records of recent wins and losses
• Tools for setting limits or taking a break

Some tools can help an adult manage their betting. But the app is still designed to make betting quick and easy.

A typical night might look like this:

Your 19-year-old is watching a game with friends. Someone sends a parlay to the group chat. Your child opens an app, sees a promotion, and places the bet. The first part wins, so everyone gets excited. Later, the parlay loses by one point. Another game is starting, and the app offers a new “boosted” bet. What began as one $10 bet becomes several bets and an evening spent checking the phone.

Teens may also try to use someone else’s account, share login information, or send money to an older friend who can place the bet if they are not of age. The legal betting age depends on the state and type of gambling.

Sports betting is now mixed into the way people watch and talk about sports.

A teen or young adult may:

• Hear the odds during a sports show
• See sportsbook logos at a stadium
• Watch an influencer share a parlay
• Hear friends discuss bets in a group chat
• See betting ads during nearly every break
• Join a fantasy league where betting is common

Over time, it can begin to feel as though “real fans” bet.

Your child may say:

• “Everyone puts a few dollars on the game.”
• “It makes the game more interesting.”
• “I know this sport, so I have an edge.”
• “It’s just what our group does.”
• “I’m not gambling. I’m using stats.”

Sports knowledge may help a person understand the game, but it cannot remove chance. Knowing a team well does not mean knowing what will happen next.

One win can also be powerful. A young person may clearly remember the thrill of turning $10 into $80. They may pay much less attention to all the smaller bets they lost.

You do not need to understand every kind of bet before talking with your child. Start with curiosity.

You might say:

“I’ve noticed that betting comes up a lot during games now. What are you and your friends seeing?”

“Do people in your group bet because they enjoy it, or does it sometimes feel like pressure?”

“What do you think happens when someone starts trying to win back what they lost?”

“How would you know if betting had stopped being fun and started causing problems?”

“You are not allowed to use my account, cards, or payment apps for gambling. If you are ever in over your head, tell me. I may not pay the debt, but I will help you find a safe way forward.”

Try not to shame your child or call them careless. A calm response makes it more likely that they will tell you what is really happening.

Parents can also think about the messages children hear at home. If adults discuss bets during every game, ask children to help pick parlays, or celebrate wins without mentioning losses, young people may learn that gambling is simply part of sports.

You do not have to stop enjoying the game. It helps to show that sports can still be exciting without money riding on every play.