LANDOVER, Md. >> The doors to the sportsbook at FedEx Field opened two hours before the Washington Commanders’ first game of the NFL regular season, drawing fans in with air-conditioning that blasted onto the stadium’s main concourse. Signs advertised a free Commanders hat for anyone who bet $20. A bouncer stood out front with a hand-held device that scanned IDs to check that patrons were 21 or older and not barred from gambling by state regulators.

A few hundred cash bets had been placed by the time Lawrence Harrod, 37, wandered in with his older brother shortly before kickoff. Harrod, who had already bet on four NFL games through a mobile gambling app, was mostly interested in taking a break from the humidity. But as he looked around the 5,000-square-foot space, which had 21 self-service betting kiosks and three dozen television screens, he clearly saw the business opportunity the NFL and its teams were seizing.

The FedEx Field sportsbook, run by the betting arm of the Fanatics sports apparel company, is the first (and for now, only) such venue operating inside an NFL stadium. It is also a physical representation of the fine line the country’s preeminent sports league is attempting to walk on sports betting, both embracing it and policing it.

“I can understand why the NFL’s stance is what it is, but it is a business,” Harrod said. “This is the future.”

Since a Supreme Court ruling in 2018 opened the door for more states to greenlight sports gambling, the NFL and its teams have increasingly embraced betting as the league’s biggest area of revenue growth. The league’s partnerships with DraftKings, FanDuel and Caesars Entertainment are reportedly worth nearly $1 billion across five years. The Commanders’ own deals were visible beyond the sportsbook, via the blue FanDuel signs over both end zones, and the logo for the nearby MGM National Harbor casino on a stadium staircase.

But the legalization of gambling has had costs, too. This offseason the NFL issued its most extensive set of penalties for violations of its gambling policy. The 10 players serving suspensions include seven who have been barred for at least this season because they bet on NFL games. And aside from disclaimers under advertisements and the occasional public service announcement, there has been little discussion of the potential effect on NFL fans who are barraged during games with enticements like a free hat or a couple hundred dollars in bonus bets.

In an interview with NBC’s pregame show before Thursday’s season opener between the Kansas City Chiefs and the Detroit Lions, NFL Commissioner Roger Goodell said the league had long opposed legalized sports betting “because of the risks with the integrity of the game.” But, he continued, “When the Supreme Court overruled that, we have to be in that space.” He suggested that the league’s business relationships with gambling entities have given the NFL the chance to educate its fans, although he did not explain in what way.

The league’s strictest gambling penalties for players are for those who bet on NFL games. Nine players in the past four years — including one Commanders player — have received at least season-long bans for betting on NFL games, after decades without any such punishments.

But three players are serving shorter suspensions for betting on other sports at their team’s facility, and the policy for coaches and other personnel prohibits any betting on other sports. This diverges from other professional leagues such as Major League Baseball, which prohibits only betting on baseball games or illegal betting.

Commanders left tackle Charles Leno Jr. said he doesn’t like talking about the gambling policy because he’s wary of saying something that could get him in trouble. But as his team’s union representative, Leno said, “I just advise guys to follow our rules. I know it can be unfair, seemingly. But at the end of the day, just follow our rules. That’s all I can advise.”

The sportsbook sits one level up from the Commanders’ locker room. It has a maximum capacity of 241 people, its foot traffic a mere fraction of the customer base online, which included fans who were able to place bets without leaving their seats. Still, the physical space was a useful marketing tool for Fanatics, a newer betting operator.

The Commanders secured a sports betting license for FedEx Field from Maryland state officials last year, and Fanatics pays the team a fee to operate the sportsbook through that license. It has been open to the general public seven days a week since January, but got a boost two months later when team owners voted to allow the operation of sportsbooks inside stadiums while home games are being played.

NFL rules do not allow teams to receive a direct percentage of money from bets placed, but the fees paid by betting operators count toward league revenue that is divided with the players, according to a league spokesperson.

Ari Borod, the chief business officer for Fanatics’ betting arm, said the NFL has taken a “pragmatic” approach in how it has embraced sports betting over the past five years, coming to see it as another way for fans to engage with their favorite sports.

“They know how important betting is to their sport, and more importantly, the betting industry knows how important football is to it,” said Borod, who has worked in the sports betting field for nearly a decade. “In the early days, there was a view that maybe you shouldn’t be able to bet at a sportsbook inside the stadium. But I think as sports betting has matured, and you realize, well, people are doing it on their phones anyway.”

The sportsbook, which is open only to ticket-holders during Commanders games, does not have a view of the field, so by kickoff of Sunday’s game with the Arizona Cardinals, only five people lingered inside on the leather couches and at the bar. At halftime, there was a steady trickle of fans, some returning to place bets based on what they had seen in the first half. Others sought a cool, dry place to order food and drinks.

“Doubling down on Washington, huh?” a fan wearing the jersey of Kamren Curl, the Commanders safety, called out to another bettor at the next kiosk over. Washington trailed the Cardinals by 3 points at halftime, but he reasoned that the home team wasn’t likely to give away the ball three more times. Another Commanders fan, standing under a television screen that displayed live odds for all of the early afternoon NFL games, begrudgingly put money on the Cardinals.

Joe D. and Jason B., two childhood friends attending the game to celebrate their birthdays, had already placed bets on a mobile app leading up to Sunday’s game. But when they saw the sign outside the sportsbook offering a free hat, they decided to venture inside, where each put down $20 more, less than the cost of any hat at the Fanatics apparel store next door.

“We never put in money we don’t have,” said Jason B., who along with his friend declined to give his last name, citing a societal stigma around gambling. “But not everyone has the ability to control themselves.”

Over the past four years, Joe D. said he has wagered around $9,000 total across all sports through a mobile betting app. Gesturing around the sportsbook in the Commanders’ stadium, and at the television screens flashing advertisements for the NFL’s betting partners, he said, “They’re clearly making money.”

This article originally appeared in The New York Times.