In the new movie “Everything Must Go,” Will Ferrell plays Nick Halsey, a Phoenix salesman who loses his job in the first scene and whose life goes downhill from there. The small-scale film required Ferrell to navigate minefields most actors would consider tricky: playing a drunk, working with a kid and trusting a first-time writer-director to nail down just the right tone between serious and funny.

Throw in the fact that “Everything Must Go,” based on a Raymond Carver short story, has nothing in common with the comedies that have made Ferrell a star, and the degree of difficulty increases exponentially. But Ferrell aficionados will remember that he has delivered convincing dramatic performances before, most notably in the 2006 film “Stranger Than Fiction.” And it was just that kind of quirky, unclassifiable movie that Ferrell was looking for when “Everything Must Go” landed on his desk.

“I really loved that experience of getting to do a straighter role, that more dramatic kind of turn, in ‘Stranger Than Fiction,’ ” Ferrell explained in a recent telephone conversation, adding that the comic actors he has most admired were able to do dramas. “I was a fan of stuff that Jack Lemmon had done, and even Tom Hanks, who I think we all now forget totally started out in comedy. Even Bill Murray, who’s one of my comedic heroes, has done such solid work in dramas now.”

Although Ferrell came to national recognition on “Saturday Night Live,” his movie career had a leg up since he started out not in stand-up but in sketch comedy — a distinction that made him less beholden to shtick and more shrewd about the subtleties of character. “I think I’ve always viewed myself as a comedic actor, with an underline under the word ‘actor,’ ” he says. “And it’s always been important to me, no matter how outlandish the character or situation, to play it very real within the context of what was going on.”

Ferrell, 43, has already received kudos for his performance in “Everything Must Go,” which debuted at Sundance in January and opens Friday in Washington. When Nick realizes that his wife has thrown all his belongings into the yard and changed the locks on their house, he makes the rash decision to simply live on the lawn, sleeping in his recliner, drinking beers and eventually befriending a youngster named Kenny (Christopher Jordan Wallace), whose mother works down the street.

The absurdist situation makes the most of Ferrell’s gift for deadpan humor, which peeks out of the story’s melancholy contours. Perhaps most crucially, Ferrell portrays Nick’s alcoholism not as a state of falling-down, slurring extremes but as a steady state of anxiety and fragile self-control.

When Ferrell and “Everything Must Go” writer-director Dan Rush first talked about Nick, they agreed that “we’d err on the side of underplaying everything,” Ferrell says. “There are a lot of ways to play that, and I told Dan, I’m just fearful — and he shared the same fear — of going too broad with it. You don’t want to get a close-up of my shaky hand grabbing for the beer can. It’s such a slippery slope.”

Rush suggested that Ferrell watch Paul Newman in “The Verdict” for ideas of how to play a barely functional alcoholic. “That’s so masterfully done,” Ferrell says. “And I just kind of relied on [Dan] to make sure that it always felt real.”

“Everything Must Go” takes place in the creamy vanilla center of American suburbia, but Ferrell, who grew up in Irvine, Calif., says his experience of suburbia was dramatically different. “We didn’t live in a house,” he says. “I didn’t live in a typical cul-de-sac. I lived in one of the few apartment complexes in Irvine that existed.”

What’s more, Ferrell’s dad wasn’t a salesman or white-collar professional but a musician, whose primary gig was playing keyboards for the Righteous Brothers. In the movie, Nick’s father was a disc jockey who also abused alcohol. “My dad definitely wasn’t that,” Ferrell says. “But I do remember him being gone for long stretches, being on the road touring.”

With the comedies “The Other Guys” and “Megamind” becoming modest and huge hits, respectively, last year, Ferrell isn’t about to leave behind the genre that has been so good to him. And, though his impersonation of George W. Bush now qualifies as an artifact of a bygone pop culture era, Ferrell says he still has political zingers up his sleeve.

He and Zach Galifianakis are writing “Southern Rivals,” about politicians in South Carolina competing in a small-town congressional race. “That’s going to be our comment on all the madness we now see in modern-day politics,” Ferrell says before signing off. “We’re going to shoot it in the fall, so we can release it just before the [2012] election.”