This is not grade school dodgeball. These are elite players hoping to be world champions right here in the theater at Madison Square Garden.

Teams from 13 countries take very seriously an activity that seems forever stuck in gym class, a sign the sport is growing up a bit. 

"It's amazing, honestly, because everybody is fully aware that this is the world's greatest sport venue," said Tom Hickson, president of the World Dodgeball Association.

Dodgeball has long been a game everyone loved to mock, which is one reason the movie Dodgeball was a hit.

The movie claimed that if you mastered the five D's of dodgeball, "Dodge, Duck, Dip, Dive and Dodge," that "no amount of balls on earth can hit you." But as I learned, those Ds aren't enough when you're facing skilled competitors who practice -- and you haven't played in more than 20 years. 

The movie, players say, was actually good for dodgeball, getting people talking about it. Now, there's even a push to bring it to the Olympics. 

"We believe the movie was the best and worst thing for the sport," said Katie Morrison, the president of Canada Dodgeball. "People, that's what they recognize. We get to have all the jokes that are behind the movie. But at the same time people didn't think dodgeball was a thing until that came out. 

Morrison has been playing for six years. Ed Prentiss, who is from Indiana, has been at it for 15 years.  

"I played this as a kid. I loved it. And just decided to get some friends together and that's how it all started," he said.  

He is in advertising, and like many competing this weekend, plays in his spare time. This is the second world cup. The first was two years ago in Manchester, England.

There are no salaries or prize money, at least not yet. It's strictly a pay-to-play sport. 

"It's all self-funded, player-funded, doing what you can to get a ticket to get to where you want to go," Prentiss said.

The rules are slightly different than what you might remember from fifth grade. Unlike in gym class, you cannot hoard balls. And the balls are cloth, not rubber. 

But one thing never changes: you still have to dodge that ball when it's coming your way.