Jumping Into the Fire : In ‘Advocate,’ Al Pacino takes a walk on the dark side. Luckily, he’s no stranger to these mean streets.

A Method actor preparing for the role of a drug addict hangs out with junkies, and observes. When he’s preparing to play a real-life cop who helped ferret out corruption among his peers, he gets to know the cop himself. But how in the devil does he prepare to play . . . the devil?

“There’s not exactly somewhere you can go for that, is there?” says Al Pacino, settling into an overstuffed chair in a hotel suite across from Central Park. He’s dressed in standard New York artist chic--black shirt, black pants, black leather overcoat. A devil-red tie is knotted loosely at mid-chest.

“Do you mind if I smoke these?” Pacino asks, holding up a pack of Honey Rose herbal cigarettes. “There’s no nicotine in them. It smells like grass, but it’s really good. When you’re working on movies where you have to smoke in a lot of takes, I recommend them.”

Pacino, of course, has played many characters who operate through a haze of smoke and vice. But “The Godfather’s” Michael Corleone and “Scarface’s” Tony Montana, to cite two, are mere soldiers in the greater crusade for evil led by Satan, whom Pacino plays, like a seductive slide trombone, in Taylor Hackford’s “The Devil’s Advocate,” which opens Friday.

Adapted from a 10-year-old novel by Andrew Niederman, “The Devil’s Advocate” is the story of a hotshot Florida defense attorney (Keanu Reeves) whose unbeaten court record and gift for spotting friendly jurors lands him a job with the international firm of Milton, Chadwick, Waters in Manhattan. Charmed by the firm’s charismatic boss, Pacino’s John Milton, the young lawyer and his beautiful wife (Charlize Theron) are soon living in a fabulous Manhattan apartment, he’s working on the highest profile murder case in years, and another Faustian trap is set.

The devil here seems tailored to Pacino’s theatrical range. Milton is confident, seductive, sly, flamboyant, lecherous, intelligent, corrupt, playful and full of rage. You ought to hear what he has to say about God. How does a nice Catholic boy from the Bronx prepare for a role like this?

“Most of the preparation here was deciding what kind of devil he would be,” Pacino says. “Everybody has an idea about the devil or pure evil, but what is he, how do you find him?”

For starters, Pacino did what any responsible movie buff would do. He watched William Dieterle’s 1941 “The Devil and Daniel Webster” and studied Walter Huston’s classic performance as Mr. Scratch.

“As soon as I saw that, I was going, ‘Whoa,’ ” Pacino says. “He was giving me wings there. It was just such a brilliant performance. Without him doing anything, he was able to make you feel the devil’s power.”

Pacino also watched Claude Rains’ churlish interpretation of the devil in “Angel on My Shoulder” and Jack Nicholson’s womanizing Daryl Van Horne in “The Witches of Eastwick.” And he may have taken another look at Robert De Niro’s ultra-sinister Lou Cyphre in “Angel Heart.”

“But the Huston movie helped me most. That kind of sanctioned it, because he was such a consummate actor attempting it. I sort of felt encouraged by that and I went off on a kind of adventure to find my own voice.”

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The adventure took Pacino into “Dante’s Inferno” and to “Paradise Lost,” whose author inspired the Pacino character’s name. But this John Milton is a devil incarnate not so much for the ages as for the ‘90s. He runs a law firm whose attorneys know how to win at any cost. Call them the Great Big Dream Team.

Scripts for “The Devil’s Advocate” have been in play in Hollywood for years, and the movie was once set up with director Joel Schumacher, who had Brad Pitt signed for the Reeves role, but pulled back when he couldn’t get the right actor for the devil. Pacino says he was offered the role a couple of years ago, but passed because the character was a sketchy, conventional monster.

“If you’re going to play someone who’s a classical character, you have to find something that at least alludes to more than a slick car salesman,” Pacino says. “You have to find some metaphor for what’s going on in our lives today.”

Neither Pacino nor Hackford will say the O.J. Simpson case inspired them, but both acknowledge that widespread lingering rage over the criminal case verdict is the climate that got the $60-million movie made.

“I think it often happens with scripts that hang around awhile,” Pacino says. “You wonder why they don’t get done, and then something changes out there and it suddenly makes sense.”

Vanity may be John Milton’s favorite vice, as he says with great relish in the film, but it didn’t hook Pacino, at least at first.

Says Hackford: “He just looked at me and said, ‘I’ve heard that one before.’ ”

Eventually, Hackford and his “Dolores Claiborne” screenwriter Tony Gilroy wrote a couple of scenes to show Pacino how the role would be “particularized” for him.

“I was interested in a devil who was sardonic, fascinating, charming, sexy and seductive, but not necessarily all-powerful,” Hackford says. “This devil operates on the power of temptation. He just puts temptation in front of them, and lets them choose.”

In the long haul, people are more likely to remember “The Devil’s Advocate” as a mischievous parody, a feature-length lawyer joke that manages to rise on the nitrous oxide of Pacino’s performance. John Milton is a devil who really, really likes his job, and Pacino, who rarely gets the chance to do comedy, seems to be having a high time himself.

“This devil has a philosophy of pure evil, but I tried to find stuff that’s funny, too,” Pacino says. “I knew we had to go for that to make it palatable. The idea of being able to run the gamut, to go from being sincere to being flamboyant to being coquettish to being enraged was a lot of fun to do.”

The devil’s shifting moods come in overlapping waves, with Pacino sliding effortlessly from one to another. In the film’s--and Pacino’s--showcase sequence, John Milton is trying to tempt Reeves’ Kevin Lomax into committing an act of cosmic evil, something that will set up the next millennium for the bad guys. One moment, Milton is railing against God, as the father who rejected him, the next he is dancing around the room lip-syncing to Frank Sinatra’s rendition of “It Happened in Monterey.”

“Al improvised that during a rehearsal,” Hackford says of the dance. “It’s a moment where Milton feels that Kevin is coming around, and he’s very exhilarated by it. All of a sudden, Al just started dancing and singing ‘It Happened in Monterey.’ I said, ‘That’s in the movie!’ ”

Pacino and Hackford both scoff at rumors reported during production that the stars were badly aligned. A Los Angeles Times article quoted unidentified crew members as saying Pacino always showed up late for work and attributed it to his disgust with Reeves’ performance.

“Al is probably the most generous actor I’ve ever seen,” Hackford says. “He could come to the set arrogant, he could come cool, and he could get away with it. But he doesn’t. And Keanu Reeves worshiped Al. They got along great.”

“The Devil’s Advocate” is Pacino’s 26th feature, marking a pace of less than one a year since his debut in the 1969 “Me, Natalie.” (“All I remember about that film,” he says, “is that Patty Duke was very nice to me.”) He’s had eight Oscar nominations, and one win (for “Scent of a Woman”), but will be forever linked to Michael Corleone.

Oddly, Pacino had never seen the first “Godfather” on the big screen until earlier this year at a 25th anniversary screening in San Francisco. It brought back memories of a young actor so overwhelmed by the nature of his role that he was actually expecting to be fired.

“I thought the role was impossible to do,” he says. “I didn’t know how I was going to go from being a nonentity to this guy who runs the whole show. Where was that? I remember staying really close to the story in my mind and heart and feeling that somehow I would chart out this character. I spent a lot of time doing that, and I spent a lot of time praying. Literally, I went and sat in churches and prayed.”

A quarter-century later, he’s playing the devil, cursing God with a fury that would make an atheist nervous. Any trepidation?

“Of course, naturally,” he says, stubbing out his last Honey Rose. “But I thought, you know, it’s about something. Its ethic is to communicate a certain thing. There is an immunity an actor has, right? I hope, I hope.”