Oscar Isaac rocked a mean mustache and mullet and Jessica Chastain wowed in a dress that looked like it was made of what she called a cooler version of bubble wrap at Thursday’s world premiere of “A Most Violent Year” at the Dolby Theatre in Hollywood, kicking off AFI Fest 2014.

The film from writer-director J.C. Chandor takes place in New York in 1981, one of the most crime-ridden years in the city’s history. Abel (Isaac) and his mob-connected wife, Anna (Chastain), fight to keep their business alive despite pressure from the city’s D.A. (David Oyelowo) and a mounting crime war against their workers.

Chandor, who was growing up in New Jersey and whose father worked in the city during the time in which the movie is set, said he had a feel for the danger and grime of the city in the period. He said he was struck with the idea of Abel’s character and a movie in that violent environment began to come together.

“I was cutting down a tree, randomly, with a chainsaw after Hurricane Sandy and the image of Oscar’s character came to me,” Chandor said. “I heard his voice for the first time, and for me that’s usually the straw to start writing.”

As for how the film achieved its distinctive 1981 New York look and feel, Chandor had a simple answer.

“Great clothes.” (Costume designer is Kasia Walicka-Maimone.)

Javier Bardem was originally cast as the lead, but dropped out due to creative differences, said Chandor. It was Chastain who suggested Isaac, with whom she studied at Julliard. Chastain relished the opportunity to act with a trusted friend in a role that demanded some tense scenes.

“When you know someone really well, you know that when you’re acting in a scene anything could happen, because you trust each other,” Chastain said. “There was one scene we were doing where I thought, ‘Hmm, he could hit me any second.’ And it was okay with me, I trusted him.”

In her character, whose family ties with the mafia loom large over the film’s proceedings, she said found both humor and tragedy, a balance she plays nicely in a role that could see Oscar consideration.

“I loved the idea of this woman who wants to push up her man, her man is her king,” Chastain said. “But at the same time, as much as she’s pushing him up she’s also emasculating him, and there’s this dichotomy in her.”

The Guatemalan native Isaac said he was attracted to the role of Colombian-born Abel because of its non-stereotypical portrayal of a Hispanic character and its exploration of the character’s life as an immigrant in America.

“(Abel) is just trying to find the right path to success, and it’s a little about the American dream, or the idea of the American dream,” Isaac said. “What the sacrifices are to achieve that.”

Isaac, who in 2013 starred in the Coen Brothers’ “Inside Llewyn Davis” set in Greenwich Village in 1961, considered the idea of doing a movie in every decade and every different section of New York.

“That’d be nice, right? Just hit all the spots, hit all the boroughs. I’m in Yonkers right now, so yeah,” Isaac said.

Bob Gazzale, president and CEO of the American Film Institute, introduced the film and AFI Fest, and after the premiere the cast and crew headed across the street to the Roosevelt Hotel for the AFI Gala with food and drinks.

Produced by Participant Media and distributed by A24 Films, “A Most Violent Year” opens in theaters Dec. 31.