Ever since his breakthrough role as the soft-spoken and sensitive Officer Jim Kurring 20 years ago in the 1999 classic film “Magnolia,” John C. Reilly has managed to earn a soft spot in moviegoers’ hearts with dozens of roles as lovable losers and everymen. He’s managed to do this with surprising range as well, scoring an Oscar nomination for his turn as the cuckolded Amos Hart in the musical “Chicago” and playing the fool with Will Ferrell in a trio of outrageous comedies including the sublimely stupid “Step Brothers.”

Reilly has always loved performing live theater most, largely because of the immediacy and intimate connection it allows between performers and their audiences. He will be spotlighting that passion for a month onstage at the Pasadena Playhouse’s Carrie Hamilton Theatre from Friday May 24 through June 22 with “Gather: Surprising Stories and Other Mischief,” alongside a team of other veteran actors who come together to act out a colorful array of stories for all ages.

“It’s a theater form called story theater, originally created by Paul Sills, who started [legendary Chicago comedy theater] Second City,” explains Reilly. “The actors tell the story as narrators at the same time they portray the characters. So I and other actors will be doing narration, jump into dialogue and then back to narration, as a group of people take the stories on.

“It’s really fun, because you create objects out of nothing, a lot like improv,” Reilly continues. “It’s gone on to spawn so many types of theater, the sort of theater that uses imagination more than technical effects. It’s a human-based theater art.”

The show’s selections include Grimm’s Fairy Tales, classic old folk tales and other family-friendly scenes — all of which are organized and edited by Reilly with his longtime artistic collaborator Patrick Murphy, who was his first acting teacher in college. The pair had been discussing teaming up for a story theater project nearly ever since, and Reilly believes that it will prove to be a powerful experience for audiences.

“The Playhouse was generous to give us this, because in this time of bad news what else can we as human beings do but come together regardless of beliefs, and tell stories to each other?” asks Reilly. “And we’ll sing some songs because the stories are interspersed with us singing old songs you might remember. You’ll have some soul nourishment, some humor and some old-fashioned theater magic.

“It’s a really intimate space, with 99 seats, and we weave this kind of dream and tell nine or 10 different stories,” he adds. “It’s really a show for young people and old, age group 8 to 800. It’s family friendly because some stories are darker than others, so we’re thinking of adding matinees to tone down the scary bits even more for really little kids.”

Reilly credits Playhouse Artistic Director Danny Feldman with thinking outside the box on “Gather,” building upon innovative programming that has restored smash-hit status to the sometimes-struggling theater since taking over from his longtime predecessor Sheldon Epps in 2017. Along with producing the month-long run of shows, Reilly is discussing bringing an acting studies program back to the theater, which used to count future greats such as Gene Hackman and Dustin Hoffman among its students.

“The Playhouse is the State Theatre of California, a community theater that brought people together in Pasadena,” says Reilly. “That’s why we called the show ‘Gather,’ because it’s a community-based thing and we share some theater magic. The opening night is my birthday so I can’t think of a better way to celebrate getting older.”

A devout family man, Reilly has been married to his wife, independent film producer Alison Dickey, since 1992 and has two children with her. He grew up in a larger family in Chicago, the fifth of six children born to the owner of an industrial linen supply company business, who was also named John.

He first took the stage at 8 years old, displaying a natural talent that enabled him to train at the Goodman School of Drama before becoming a member of the Steppenwolf Theatre, one of America’s most acclaimed dramatic institutions. His time at the Steppenwolf included a Tony-nominated run on Broadway when the troupe visited the Great White Way with the classic Sam Shepard play “True West.”

Yet asking him for a favorite genre of acting he’s performed in, and Reilly is sincerely challenged to decide.

 “People come up to me every day who don’t say the comedies are their favorites, but say ‘Chicago’ the musical or {the Martin Scorsese historical drama] ‘Gangs of New York,’” he says. “A lot of actors get pigeonholed by audiences wanting them to do the same thing over and over again, but I’m lucky people expected the unexpected from me: funny, sad, scary, sci-fi and everything in between.

“The simple answer is I’m just lucky I guess,” he concludes. “People let me do different things, so I change it up project to project to feed my soul. This project is another example of that. A lot of people have seen my works over the years. People come see me in films and can come and be in the same room as me and share magical moments together. It’s maybe not the greatest career move but it’s important to me to join me and feel better for a couple hours.”

“Gather: Surprising Stories and Other Mischief” opens at 8 p.m. Friday in the Carrie Hamilton Theatre of the Pasadena Playhouse, 39 S. El Molino Ave., Pasadena. Tickets are $56. Call (626) 356-7529 or visit pasadenaplayhouse.org