“I like the idea of movies having a magic element.”

BEVERLY HILLS, California - Christian Bale does not like to talk about himself and what he called “the extremely silly profession” of acting. But he is putting up with the scrutiny for the sake of his new movie, “The Fighter.”

Directed by David O. Russell (“Three Kings”), the film, opening worldwide this winter and spring, is a long-nursed passion project of Mark Wahlberg, who served as producer and stars as Micky Ward, a former boxing champ and local hero in the working-class city of Lowell, Massachusetts. But the meatiest role belongs to Mr. Bale, who plays Micky’s shiftless trainer and half brother, Dicky Eklund, whose own career derailed when he developed a drug habit.

Dicky is a departure of sorts for the Welsh-born Mr. Bale, 36, who has produced a series of haunted, inward performances in such movies as “Prestige,” “3:10 to Yuma” and “Public Enemies.” And in Christopher Nolan’s “Batman Begins” and “The Dark Knight” ? they are teaming for a third ? Mr. Bale made for a stoic superhero.

“One of the great things about Christian is his refreshing lack of ego,” Mr. Nolan said. “He figures out how he can be useful to the storytelling.”

Mr. Bale’s transformation into Dicky is of a piece with his other physical feats: embodying the buff, preening lunatic of “American Psycho” or the emaciated insomniac of “The Machinist,” for which he famously lost 27 kilograms.

“The Machinist” remains the most vivid example of Mr. Bale’s deep-dive approach to character immersion. It introduced him to what he called “a commitment level which I discovered I greatly enjoyed.” Shedding a third of his weight might seem the ghoulish ultimate in actorly masochism, but Mr. Bale speaks of it almost as a purification rite. “I’d felt a real staleness in the work and that rejuvenated me,” he said.

Mr. Russell marveled at Mr. Bale’s dedication to staying in character while shooting “The Fighter.” “I don’t know what I do,” Mr. Bale said. “If other people look at that as staying in character, I’ll take their word for it.” (Last year a recording of Mr. Bale exploding on the set of “Terminator: Salvation” was leaked ; the 10-minute tirade is delivered in the American accent he adopted for that film.)

“I kind of slowly do it,” he said of his acting method, “like a frog that you stick in cold water and slowly turn up the heat so it never knows it’s being boiled alive.”

Mr. Bale ‘s breakout role came when he was 13, in Steven Spielberg’s “Empire of the Sun.” Batman gave him new clout, and new challenges. In shooting Werner Herzog’s prisoner of war drama “Rescue Dawn” in the jungles of Thailand, he ate maggots and wrestled snakes. Which is as good as it gets for an actor, Mr. Bale said: “I can’t control the end result,” he said, “so I look at the process as an incredible opportunity to have experiences and test yourself.”

Mr. Bale’s views on artistic privacy are related to his faith that an anonymous actor is a more credible shape shifter. “I like the idea of movies having a magic element,” he said.

“How many times have you seen an actor in a movie who you know only as the character? It’s wonderful, isn’t it?”

He guards his personal life ? he and his wife , Sibi Blazic, have a 5-year-old daughter ? and save for the “Terminator” blow-up and allegations of verbal assault on his mother and sister in 2008 (the charges were dropped), he has not gotten much tabloid attention.

“A movie star is someone people look at and go, ‘I want to be like that person,’ ” Mr. Bale said. “There’s the responsibility of desire. It’s not something I’m interested in trying."


By DENNIS LIM