Marc Maron has interviewed everyone from Bruce Springsteen to President Obama, so he’s probably learned a few things about being a good interview. Of course, as he points out, he generally has over an hour to talk leisurely speak with his guests in his home and draw out stories beyond the public narrative; it’s a little harder when he’s in the process of giving dozens of interviews largely in press junket settings for his new movie, “Sword of Trust,” now playing in New York and Los Angeles.

Still, Maron doesn’t disappoint, giving frank and honest answers to questions both silly (the avowed cat lover has yet to see the trailer for “Cats,” which dropped the day before this interview) and methodical – specifically, how does one excel in this niche of improvised narratives he’s carved out lately working with the likes of Joe Swanberg and Lynn Shelton?

Shelton is Maron’s frequent collaborator, having directed him multiple times on his eponymous IFC show “Maron” and the Netflix hit “GLOW” and had been looking to make a movie with the actor/comedian/podcaster for some time. In “Sword of Trust,” written by Shelton and Mike O’Brien, Maron plays Mel, a cranky pawn shop owner who, with his slacker assistant Nathaniel (Jon Bass), gets involved with a fringe organization who believe the South won the Civil War. Mel agrees to facilitate a trade between the group and a couple (Michaela Watkins and Jillian Bell) who have inherited the weapon in question. Shot in 12 days in the heat of Alabama, “Sword of Trust” is full of comedy both broad and thoughtful, and an excellent showcase for its actors, particularly Maron.

What was the impetus for this story and this character?
She was getting antsy to shoot a movie with me in it and I was like, “Come up with one!” She apparently drove by a pawn shop and said that’s where I needed to be, among the sad merchandise people had to let go of for desperate reasons. Then she knocked out a script with Michael O’Brien and said, “We’re going to shoot it.” I kind of didn’t believe it was happening until it was happening.

I know this is largely improvised; is there a script or are you working off a treatment?
It’s a pretty detailed scriptment, as she calls it, a hybrid of a script and a treatment. There might be some lines in there but they don’t necessarily need to be honored. So the story points are all pretty plotted out but you get to that point where we’re in the back of the truck, which is a long scene, and all it says on the page is: “They get to know each other.”

You’re kidding, because you have you monologue in that scene that is amazing.
Yeah that was all improvised. I mean, you do the scene a few times so you get a feel for it. And before you shoot, Lynn sits down and you work out a collaborative backstory. If you have a relationship with someone in the movie, you work together on that. Like Michaela and Jillian spent time together. I spent a little time with Jon Bass, and that was annoying.

Why annoying?
It’s not contentious, it’s endearing. We fell into that dynamic you see in the film pretty quickly. We set it up that he was going to see me do comedy one night at The Comedy Store, and he immediately sort of annoyed me in the way he does on camera. So it worked out for the movie.

I find regular acting scary enough, this seems particularly terrifying. Does it get less scary?
I don’t know if it was every terrifying. I come from a stand-up background, I’m not a sketch performer or an improv guy so I really talk through everything. I guess I’m an improvisational guy I’m just not used to doing it with other people – except the audience. But it’s in my wheelhouse. The other actors are so proficient I was a little intimidated at first. But it’s so organic the way ideas and emotions unfold and you can see that. So many bigger-budget screen comedies are so sterile by the time they get on screen, there is something so watchable about this.

Lynn herself plays your ex-girlfriend and she’s fantastic! I didn’t even realize that was her at first.
Yes! She’s got some chops. She actually started as an actress in college, I believe. She doesn’t do it too much. Apparently Michael O’Brien kept putting her on the cast list and she kept saying no. But she ended up doing it and it was great.

What’s it like to have someone like Lynn be your champion; I’m kind of hoping you two are the new Scorsese/DeNiro.
It’s great, we got along right away very well when she did my podcast back in, I think, 2015. She directed a couple episodes of my show and then we were paired up on “GLOW” together again. I was pretty stubborn and defensive at first and a creative relationship evolved. She directed my last comedy special and we’re going to do another one in October. She’s very astute and empathetic with the emotional dynamics of a scene and with me, too.

Do you mean you were stubborn as an actor?
Early on, I didn’t know how to take any notes as anything other than personal criticism and I could be belligerent. Over time, that eases up and I grew to trust her. I think it’s a natural process.

Did you spend any time investigating these sort of conspiracy theories you see in the movie? I assume the group in the film isn’t real, but it could be.
I don’t think this particular group exists but there are certainly similar types. Jon did a little more research and Lynn was struck by it because she took an Uber ride with a guy who was an actual flat Earther.

On your podcast, you seem kind of surprised by the critical success and great audience response to the film.
After interviewing enough directors and actors, you realize hundreds of independent films are made every year and not all of them see the light of day. It’s a crapshoot. So I had no expectations. Lynn’s last movie, “Outside In,” is genius; it’s beautiful, and it kind of came and went. I liked the movie and when we premiered it at SXSW, I realized how unique and funny and deep and emotional satisfying it is and the comedy gets a lot of laughs. In this landscape, who knows what’s going to get through. It’s surprising and exciting it’s broke through.