Appropriate Star Michael Esper Opens About Channeling His 20-Year Sobriety in New Broadway Hit (Exclusive)

“I definitely wouldn’t be here if it weren’t for my sobriety,” the ‘Fallout’ actor tells PEOPLE

Playing a recovering addict in the critically acclaimed Broadway production of Appropriate is something that hits close home for Michael Esper.

The actor — known for nearly two decades of roles on Broadway, including American Idiot, The Lyons and The Last Ship — tells PEOPLE he’s been sober for nearly two decades, an experience he channels eight shows a week in Branden Jacobs-Jenkins’ hit play.

“I’ve been in recovery for 20 years so there’s a lot about Franz I understand implicitly,” Esper, 47, says of his character, the black sheep of a family who reunites with his siblings (played by Sarah Paulson and Corey Stoll) after multiple attempts to get clean. “It’s added a really incredible dynamic to working on him.”

In fact, Esper admits he’s “not sure how [he] would have been able to work on the character without it.”

“Thinking about where he is in his recovery, I’ve met him before. I’ve been him before,” Esper says. “He’s me at a beginner’s meeting, or me counting days. The details of our lives might be different, but in recovery, you learn a lot about the things that connect our experiences being a lot stronger than the things that make them different.”

“I just know things about him I don’t think anyone who isn’t in recovery would really get,” he continues. “Part of what breaks my heart about him is his intentions are really genuine and he is desperate to heal for both himself and for the people in his life. I really believe that about him. But he’s sort of forced to do it before he’s ready. He’s not ready to make an amends. He doesn’t know what an amends really is. He’s not prepared, he doesn’t have enough work in yet. And it just goes downhill from there on.”

Appropriate follows a trio of siblings who return to their father’s Arkansas house after his death to deal with the remains of his estate. But when mysterious objects are discovered among the clutter, suddenly, long-hidden secrets and buried resentments surface as the family is forced to face the ghosts of their past.

The Second Stage Theater production — now playing at the Belasco Theater in New York City — opened to rave reviews in December, the family drama striking comparisons to Tony-winning pieces like August: Osage County and The Humans. It’s also become the go-to stop for celebrities, with famous faces like Angelina Jolie, Cate Blanchett, Lupita Nyong’o, Bradley Cooper, Pedro Pascal, Jennifer Lawrence, Cynthia Erivo, Jennifer Garner, Colin Jost, Scarlett Johansson, Hugh Jackman, Rebel Wilson, Sally Field, Katie Holmes, Demi Moore and Goldie Hawn stopping by to see the show (among many, many others).

“It’s incredible,” Esper shares of the response. “It feels amazing to be working on something you love and believe in, and have people you really admire come and see it. But it’s also nerve-wracking. I get really nervous when I knew they’re there, even all these years in!”

“I’m just happy so many people are responding to the play, because Branden’s writing is really extraordinary,” Esper continues. “He’s able to write both deeply, personally, and politically, at the same time, without you even really knowing that he’s doing it most of the time. And he understands humor really well, as a tool, and perfects it into this kind of dangerous comedy. It just still knocks me over.”

Working with Paulson, 49, and Stoll, 48, has been “a dream,” Esper says.

“Sarah and Corey are just truly astonishing actors and people, and building a family with them was a lot easier than I thought it would be,” he gushes. “But they’re so extraordinary that a lot of the work, honestly gets done just by showing up; just by being present with them and taking in the way they’re behaving, the things they’re saying to you, the way they’re treating me. And then just let the play carry that out into the performances.”

The play also stars Natalie Gold, Graham Campbell, Alyssa Emily Marvin, Lincoln Cohen and Everett Sobers. Elle Fanning, who made her Broadway debut in the play, left the production in March, with Feud star Ella Beatty replacing her.

“Ella is extremely gifted,” Esper says of the daughter of Warren Beatty and Annette Bening, who is playing Franz’s fiancé, River, and is also making her Broadway debut in the production. “She’s extremely well-trained, very assured and hugely accomplished. She’s had acting jobs before I could even imagine what that was. So I feel honored to be working with her every night.”

As for the arc Esper’s character goes through each night in Appropriate, the Fallout actor handles the twists and turns with a sense of earnestness, leaning into what he believes are the character’s “best intentions.”

“There are a lot of things about Franz that scared me; that upset me. It’s really hard what Franz goes through with the play, and not undeservedly either,” he expalins. “But I want him to line up with the rest of the play, which really asks the question about what is forgivable? What does it mean to even forgive somebody? To forgive ourselves? How do we live with having done terrible things; with other people having done terrible things? What does it mean to recover from those things? Is that even possible?”

At least Esper, himself, knows the possibilities of recovery. He tells PEOPLE he’s “really grateful” for everything his sobriety has brought him.

“I definitely wouldn’t be here,” Esper says. “I definitely wouldn’t be here if it weren’t for my sobriety. That I know for sure.”

Tickets for Appropriate are now on sale. The production plays through June 23.