In the ultimate throwback to childhood, groups of adults gather every week to whirl red balls at each other in a game of dodgeball.
They get in a pretty good workout, too.
For most grown-ups, it's been a while since their last dodgeball game.
"This is my first year out, haven't played in like 20 years," player Bernie Verwiel said.
Just in case you've forgotten, the goal is to eliminate players on the opposite team by hitting them with a ball, catching a ball thrown by them or forcing them to move out of bounds.
The stakes aren't quite as high as the world championships in the popular 2004 Dodgeball film, but it's just as fun and just as competitive for the Chicago players.
"If you can dodge a wrench, you can dodge a ball!" said team co-captain Christa Suk, recalling a funny scene from the film.
"I'm probably more like the Vince Vaughn character, somebody that's gonna come through in the clutch, win the game," said Verwiel.
The adult dodgeball league is organized by the Chicago Sport and Social Club. Players get together in local gyms and face off on coed teams.
"It's a lot of fun to take out your frustration from the day at other people," player Jeff Boland said.
"Yeah, there's nothing like whipping a ball at somebody, hitting them in the head, feels good," added Verwiel.
The players even have fun with what they call their teams. In one matchup, the "Dodging Devil Donkeys" took on "You're Killin' Me, Smalls."
"Have you ever seen the movie The Sandlot? It's the motto of this one player who is just not doing very well, and they yell at him like, 'You're killin' me, Smalls!'" said Suk.
Dodgeball is also a good way to burn some fall calories, players say.
"It keeps you active, I think, during some of the cooler months when the weather's not as nice," said team co-captain James Murphy.
"Any time you don't have to go to the gym, it's a good thing because going to the gym sucks," said Verwiel.
"You'd be surprised how much of a workout it is. You're running around, and then the next thing you know, you're sweating," Boland said.
In fact, the games can get so active and intense that participants sign waivers before they play.
What players say they enjoy the most is the fun atmosphere, but they can get pretty serious about it, too. After weeks of regular season games, the top teams move on to the playoffs.
In the mean time, many players celebrate weekly -- just because.
"We lost the game! They had seven, we had two," said Suk. "I had a great time. I played terribly, but I had a great time!"
Chicago Sport and Social Club's dodgeball leagues play in winter, spring, summer and fall, according to the group's website. For more information, visit www.chicagosportandsocialclub.com.