KANSAS CITY, Mo. — If you build it, they will come, and Chiefs are certainly building a football dynasty in Kansas City.

Arrowhead and the Kansas City Chiefs played host to the World’s Largest Tailgate.

Roger Goodell and Donna Kelce were there outside Arrowhead for the tailgate broadcast around the world.

Fans booed Goodell as he said he already had the script in hand for the 2023 NFL season while Kelce answered questions about her two sons, avoiding giving away any hints of Travis Kelce’s playing status.

There was live music from “Two Friends” and of course lots of Chiefs fans. The event and atmosphere even impressed Lions fans.

“I’m from Detroit what an atmosphere this is amazing the people here are phenomenal the party the ambience it is unbelievable you have to experience this once in your life time, you guys do it right here in Kansas City,” Monty Kamposh said.

Chiefs Fan of the Year Kelly Kennedy was also surprised on stage with two tickets to this year’s Super Bowl.

“When they asked me if I would accept the Legacy Seat, that was a surprise and I still haven’t come down from that yet. This is mind-blowing, I don’t know what to say that was so cool!” Kennedy exclaimed.

Kansas City Chiefs fans were raring to go Thursday for the NFL’s opening day at GEHA Field at Arrowhead Stadium. The last time they were tailgating, it was ahead of the AFC Championship game.

Fans watching Thursday night’s home opener are coming from as far as New York, the West Coast, and Texas; many of them are buying the best gear Rally House has to offer.

Of course, a lot of people were caught in traffic, trying to get into stadium closer to kickoff between the Kansas City Chiefs and the Detroit Lions.

But then again, there were fans who were there before daybreak and hitting the tailgate in champion-level form when parking lots opened early.

Take, for example, Johnathan Crocker from Lawrence, Kansas. He was at the front of the line waiting for the parking gates to open at Arrowhead Stadium. His vehicle: a small bus painted red.

Stepping inside, the signatures on the ceiling are immediately noticeable. Crocker said he started the tradition when he got the vehicle because he wanted each visit to be memorable.

But being the owner of a party bus comes with a certain amount of forethought.

“Actually no because … whenever I bought this bus, I went to the guy and I said ‘OK, this is what I’m looking for, but I got to measure it because it has to be under 21 feet so I can fit in a parking stall,’” Crocker said.

The Chiefs fan knows parking is pricy enough, and it’s even more expensive for buses and RVs.

When gates opened, trucks and SUVs hit the gas like a drag race. It was a moment of stress that was at odds with the hours leading up to it when fans had nothing but time.

“We set our alarms for 3, and my mother-in-law was already up and in the shower before our alarms even went off,” said Mitzi Wilson, a Chiefs fan from Winfield, Kansas.

“We were here at 6:30 this morning, and we have literally a tiered system to our tailgate. We have an early tier, which would be us, the full degenerates,” said Seth Teague, a Chiefs fan from Kansas City’s Waldo neighborhood.

Teague represents the party-animal contingency of the crowd — a part of, but separate from, the sports stat-heads and the lawn-game aficionados.

“We’ve had people coming in that are Chiefs fans from Canada who drove all the way down for the game tonight. They were coming in to get their gear. It’s just been incredible,” said Mandy Roode, who works at the Rally House next to Power and Light.

It’s not just people painting the town red, blue jerseys are popping up too. The Goode family traveled from Flint, Michigan to cheer on their Lions.

It marks their first visit to Kansas City, which can be uncomfortable being a Lions fan in Chiefs territory.

“Well, we got to watch what we say I guess here. We don’t know, but there’s lots of Lions fans here. Flights were full of Lions fans,” said Kelly Goode, who brought his two sons with him to their first NFL game outside of Michigan.

But the Lions roar might be drowned out by the Chiefs cheers as dozens of fans packed Power and Light for the first time since the team’s Super Bowl win in mid-February seven months ago.

“The atmosphere. It’s so energetic here. The music’s always playing. There are awesome drinks, and you meet so many people,” added Shayla Mille, who left work early to get the perfect spot ahead of the game.

Another party animal example, finding life through merch, is Lee’s Summit resident Wes Williams, ready with his Andy Reid-inspired Hawaiian shirt and replica Super Bowl ring.

“And I’m going to wear that belt,” he said, pointing to a WWE style championship belt with extra Chiefs logos.

The Chiefs-Lions matchup is also a clash of fan perception with both sides reflecting on rocky pasts. The Lions, of course, have had a more recent rocky past.

“For us, it’s been way too much hype this offseason, OK? So expectations are really high, which if you know the Lions, that’s a little strange,” Lions fan Kyle Talleur said.

“We’re improving every year, so that’s good,” said Tom Seifert, a Chiefs fan from Wichita. “There was a long time that it wasn’t like that.”

“I’m 44 years old, lifelong Chiefs fan. I have been through a lot emotionally. So I’m not taking any of this for granted,” Teague said.