LAS VEGAS — Super Bowl opening night evolved into a wacky, circus-like spectacle long before Las Vegas had a chance to host the NFL’s biggest game.

There’s no telling how wild it will be for Sin City’s media extravaganza.

The Kansas City Chiefs and San Francisco 49ers are in town and will officially kick off the festivities Monday night at Allegiant Stadium when they meet with thousands of media members from across the globe.

The event is open to fans who purchased tickets, and it will be the first and only public appearance this week for every player and coach from the two teams.

They’ll field questions ranging from serious to silly. They’ll be asked to discuss personal topics and to participate in goofy skits.

This is where a female reporter once showed up in a wedding dress veil and proposed to Tom Brady. Back then, it was called media day and took place on Tuesday.

Now, it’s live on national television in prime time.

More than 6,000 media members from 26 countries are accredited to cover the first Super Bowl in Las Vegas and related events onsite in the gambling capital of America. Some will show up to opening night dressed in costumes with no intention of talking about anything that’ll happen on the field.

Players can be overwhelmed easily if it’s their first time. The Chiefs are aiming to win back-to-back Super Bowls and are making their fourth appearance in five years. They’re used to this craziness.

“It’s exciting. It’s all exciting stuff,” Kansas City’s star tight end Travis Kelce said. “It builds and sets the tone for the whole week. It’s the biggest stage in the world. Monday night is going to be where it starts for everybody. At this point, I just love it, it’s an exciting time. It’s a once-in-a-lifetime type of thing that I’ve been able to enjoy a few times.”

The Chiefs beat the 49ers in the Super Bowl four years ago in Miami. Brock Purdy is in his second season with San Francisco, so it’s a new experience for him.

“Obviously, it’s a big game and trying to handle everything up until we leave and get on the plane to go to Vegas,” Purdy said last week. “Just in terms of who’s going to the game, all that kind of stuff. Obviously, our scheme and what we’re trying to do against the Chiefs so that when we get on the plane and we’re going through all this stuff throughout the week, we understand what we’re trying to do and the plays that we’re running and all that stuff.”

Niners coach Kyle Shanahan is heading to his third Super Bowl, including one as an offensive coordinator with Atlanta. He also saw how his dad, two-time Super Bowl champ Mike Shanahan, handled the week.

“You try to get as much in this first week as possible,” he said last week about the team’s practice routine. “When you get out there, we go through it again. But it is different. Our Monday’s totally different with the media deal. Our routine’s off because you’ve got to do these press conferences every day. So you get about an hour off from all your normal times. So when you usually do red zone and stuff, you’re two hours behind. A little more tired. All that stuff adds up. If you put stuff off to that week and think it’s going to be a normal week, you’re going to get to that Thursday or Friday and not quite feel as comfortable.”

Football comes Sunday. The real hype starts Monday night.

Whichever team handles the distractions all week the best has a better chance to hoist the Vince Lombardi Trophy.