The NFL was 43 years old when Hall of Famers Paul Hornung of the Packers and Alex Karras of the Lions were sidelined for the entire 1963 season as the first players ever suspended for gambling.

Another 55 years passed with only one more player — Colts quarterback Art Schlichter in 1983 — suffering the same fate.

Times, well, they've been a-changing the past four years.

Since 2019, the league has issued 12 gambling suspensions, including 10 this offseason alone.

"Prior to 2018, the only place to legally gamble on sports was by physically going to Las Vegas," NFL spokesman Brian McCarthy said. "It's the ease and accessibility of betting on mobile apps that has changed. What hasn't changed is the league's protection of the integrity of the game on the field."

With sports betting now legal in 38 states, the NFL is concerned enough to launch an education program that will annually encompass more than 17,000 people from the league office to all 32 teams to all gameday personnel, including members of the chain gang.

The entire Vikings organization went through its roughly 45-minute mandatory gambling policy meeting with a member of the NFL's compliance team on Thursday. The team came away with a much clearer understanding of what is and isn't permitted in today's technologically advanced gambling world.

"The way they did the meeting was good and probably could have started with an apology and a, 'Hey, we wish we would have done this in the past to let guys know,' " said Vikings defensive lineman Harrison Phillips, the team's player union rep. "I'm sure the information was available before, but it wasn't as clear as it was in the meeting. The meeting is an important piece to the compliance, something they should have been doing, but I am appreciative that they're doing it now."

The league message, according to McCarthy, isn't difficult to follow.

"Don't bet on anything related to the NFL," he said. "And if you bet on other sports, do it legally and don't do it while at work. Not at the team facility, stadium, en route to another city for a game, team hotel, etc."

Gambling on NFL games resulted in one-year suspensions for Hornung, Karras and Schlichter. Joining them was Arizona's Josh Shaw in 2019 and Atlanta's Calvin Ridley in 2022.

Suspended indefinitely through at least the end of this season for betting on NFL games last season are Denver's Eyioma Uwazurike, Indianapolis' Isaiah Rodgers and Rashod Berry, Detroit's Quintez Cephus and C.J. Moore, Washington's Shaka Toney and free agent Demetrius Taylor, who played for the Lions in 2022.

Suspended for the first six games of this season for betting on non-NFL sports while at work were Tennessee's Nicholas Petit-Frere and Detroit's Stanley Berryhill and Jameson Williams.

"Some of it's kind of silly," Vikings center Garrett Bradbury said. "I understand the integrity of the game, and you obviously shouldn't gamble on your own league.

"The other rules? I mean we can't gamble on other sports on our phone in the facility, but if we take two steps outside the facility, we can gamble on everything but the NFL. I can't say those are the best rules ever, but we still have to follow them. I don't know. I can go to Mystic Lake and play some blackjack, so I'm good."

The lines between gambling and the NFL have been blurred over the years with a team located in Las Vegas and the league now in partnership with DraftKings, FanDuel and Caesars. The league notes that players share the revenue from those gambling websites because that money is included in the calculation of the salary cap.

In trying to avoid confusion in this new era, the NFL put together a bullet-point display to accompany its training sessions. It's called the "six main rules for NFL players."

• Don't bet on the NFL. Period. Includes other NFL events such as the Draft, Combine, Pro Bowl and NFL Honors.

• Don't have someone place a bet for you. Do not ask family, friends or significant others to place a bet for you.

• Don't gamble (no bets on sports, casino or card games) at your team facility/stadium, while traveling for a road game or staying at a team hotel.

• Don't share team "inside information." Do not share information that has not been publicly announced by your team.

• Don't enter a sportsbook during the NFL playing season.

• Don't play daily fantasy football.

Added to that list for coaches, staff and personnel is this bold-faced no-no: Do NOT bet on any sports!

The league's gambling policy was on the mind of Kwesi Adofo-Mensah last Tuesday when the Vikings general manager was asked on the eve of training camp what he was "betting on" this season in terms of his team's strengths.

He smiled and said, "I don't think I'm allowed to bet."

Vikings linebacker Jordan Hicks has his own way of handling gambling: "I just don't do it," he said. "I'm not into gambling, so it's not an issue for me to take note of personally.

"But obviously, as part of a team, it is a subject to take note of because guys are getting suspended around the league. If the league is going to make a big deal about it, it has to be communicated the right way and guys need to pay attention and follow the rules."

Watching five members of the division rival Lions get suspended this offseason was more than enough for Adofo-Mensah and coach Kevin O'Connell to make gambling a special point of emphasis going forward.

"Kevin is so thorough and intentional about what he communicates to the team," Adofo-Mensah said. "We're just trying to make sure we hammer home the exact rules and then do it repeatedly so that there is no room for misunderstanding."