People in North Carolina may have a little more riding on this year’s NCAA men’s and women’s basketball tournaments, as they will be able to legally bet on the games through their smartphone apps and computers for the first time.

For the sixth straight year, the number of states allowing legal sports betting has expanded since the last rendition of March Madness. A total of 38 states and the District of Columbia now allow some form sports betting, including 30 states that allow online wagering, along with the nation’s capital.

That’s up from one state, Nevada, where people could legally wager on games during the 2018 college basketball tournaments, before the U.S. Supreme Court cleared the way for expansion.

The rules for sports betting vary by state. Some states prohibit bets on home-state college teams or the performance of specific players. Others allow bets not only on the outcome of any college games but also on a variety of other things, such as the number of points, rebounds and assists that a particular player will tally.

Here are some things to know about sports betting as the tourneys open, with the men’s games starting Tuesday and the women’s competition beginning Wednesday.

Big money

Fans have long filled out NCAA tournament brackets while wagering in office pools or against friends and family. But those casual bets have increasingly been supplemented with more formal gambling.

The total amount bet on all sports through legal wagering sites exceeded $121 billion in 2023, up 30% from the previous year, according to the American Gaming Association. After paying out winnings, sports betting operators reaped $11 billion in revenue, up from about $7.5 billion the previous year.

The American Gaming Association estimates $2.7 billion will be bet this year on the NCAA men’s and women’s basketball tournaments through legal sports books.

“March Madness is the biggest kind of individual event of the year for sports betting,” said David Forman, the American Gaming Association vice president of research.

The Super Bowl also draws big bets, but it’s only one game between two NFL teams. The NCAA Division 1 men’s and women’s basketball tournaments feature a total of 136 teams playing 134 games over three weeks.

Can you bet on your teams?

Despite living where sports betting is legal, some fans still could be blocked from betting on their favorite teams and players.

Roughly a dozen states bar bets on college games involving home-state teams. Four additional states — Connecticut, Massachusetts, Rhode Island and Vermont — generally prohibit bets involving their own college teams but make exceptions for tournaments.

Some states only allow bets on the outcome of college games, not how particular players will perform. Maryland and Ohio, for example, banned so-called proposition bets on college players, effective this month.

The NCAA has raised concerns that player-specific bets can lead to problems, including the harassment of college athletes and strain on their mental health. The organization also says such bets could entice players to wager on themselves or alter their play to affect stats-based bets.

Since the University of Connecticut won the men’s tournament last year, half a dozen states have launched or expanded sports betting.

Nebraska began taking sports bets at casinos last June, though it doesn’t allow mobile wagers. Kentucky launched sports betting in September to coincide with the start of the NFL season, and Maine began doing so in November.

After a court victory, the Seminole Tribe of Florida in December began taking online sports bets in addition to wagers at its casinos. Wagering has continued while a challenge is pending before the Florida Supreme Court. Opponents also have asked the U.S. Supreme Court to take up the case.

In January, Vermont launched online sports betting.

North Carolina, which previously allowed sports betting only at three tribal casinos, began permitting online sports wagering statewide on March 11, a day before the start of the popular ACC men’s basketball tournament but a day after the women’s tournament ended.

Odds for other states

Several states have a chance to join the sports betting trend.

In Missouri, where legislative attempts have repeatedly failed, the St. Louis Cardinals are leading a coalition of professional sports teams supporting an initiative petition that could place sports betting on the November ballot. Sports betting operators DraftKings and FanDuel have contributed a combined $3 million to the effort. Supporters say they are on track to exceed the required signatures by a May 5 deadline.

Lawmakers in Alabama and Georgia also are considering constitutional amendments authorizing sports betting. Georgia senators passed a measure last month, but it still needs a two-thirds vote from the House to appear on this year’s ballot.

Alabama’s House included sports betting in a wide-ranging gambling measure, but the state Senate stripped it out earlier this month. The House now must decide whether to accept that change or negotiate a final version to go to voters.

Legislation to legalize sports betting also is pending in Oklahoma and Minnesota. A Minnesota state Senate committee endorsed a revised version on Thursday that would raise the proposed tax rate.

Mississippi, which legalized casino sports betting in 2018, is considering an expansion to online betting. A bill passed the House last month and is now in the state Senate.

Crossing state lines

Although sports betting remains illegal in a dozen states, some residents place bets by crossing state lines. In Missouri’s two largest cities, St. Louis and Kansas City, some people drive to the nearest commuter lots or highway exit ramps just across the border in Illinois or Kansas, respectively, to place legal bets through mobile apps.

Many other would-be bettors get thwarted by technology.

During the weekend of the Super Bowl, where the Kansas City Chiefs defeated the San Francisco 49ers, technology company GeoComply Solutions said it processed more than 431,000 location checks from about 40,500 mobile devices in Missouri that attempted to access other states’ legal sports betting sites. The location checks allowed those bets to be blocked.

During that weekend, GeoComply said it processed an additional 256,000 location checks for sports betting sites coming from 30,000 devices in Alabama, Georgia, Minnesota and Mississippi.