Isla Fisher called it chasey.
Jon Hamm called it tag.
Fisher was raised in Perth and Hamm in Missouri, but despite the Hollywood stars growing up more than 17,000km apart, pursuing their friends around playgrounds and their neighbourhoods was a staple of their young lives.
Fisher, the red-haired Australian actress, 42, and Hamm, 47, best known for his Emmy-winning role in the TV drama series Mad Men, retreated back to their childhood memories for their new comedy film, Tag.
"We actually played chasey which was the Australian equivalent of America's tag," Fisher explained in a recent interview in Los Angeles.
"A bit later we did kiss chasey.
"You chase the boys and try to kiss them, but the only time I successfully kissed anyone they had a helmet on and I knocked my teeth on his helmet."
Tag is based on the true story of a group of American men who began playing a game of chasey or tag 28 years ago at their Spokane, Washington high school.
The game never ended.
Today they are aged in their 40s, most are married with children, they live in different parts of the US and have jobs ranging from a Catholic priest to a chief marketing officer at the upmarket US department store Nordstrom.
But, during the month of February each year their game of tag continues.
The player who is "it" travels cross-country without warning, uses disguises and ambush strategies to tag their friends, who are on high alert and tell family, friends, work colleagues and even security personnel to be on the lookout for suspicious people.
They credit the game for keeping their friendships strong for almost three decades.
The fun, private game among friends became a national story when the Wall Street Journal wrote about it in 2013.
Hollywood immediately saw the potential for a film and went into a frenzy to acquire the rights, with producer Todd Garner the eventual victor.
Tag's cast also includes Oscar nominee Jeremy Renner, Ed Helms, Jake Johnson and Hannibal Buress.
"I grew up with a single mum and living in apartment complex basically," Hamm, recalling his childhood, said.
"There were a lot of kids in the apartments so you just had this pack of kids that just every day after school used to meet up at a suggested spot and say 'What's today's game?' Hamm said.
"It was always some version of tag.
"We didn't have much money.
"We weren't rich.
"Often we'd end up standing on either side of a ditch and throwing dirt at each other."
Fisher and Hamm, just like the men who the Tag film is based on, remain good friends with the kids they grew up with back in their school days.
"My best friend Angie, we went to ballet class and primary school together," Fisher said.
Fisher and Angie were known as Whippy and White Fang around their Perth primary school playground.
Angie scored her nickname because of an odd tooth that grew high on her gum around the same time as the 1991 US adventure film White Fang was released.
"All of the boys just called her Fang, White Fang and Fanger," Fisher said.
"My nickname was Whippet, which became Whippy because I couldn't gain weight.
"I was so skinny.
"No matter how much I ate I always was just so skinny."
Tag releases in Australia on June 14.
Australian Associated Press
Sign up for our newsletter to stay up to date.