When his last two movies bombed, some wags predicted that the old Jack Nicholson magic had dimmed.

But with his meandering brow and devilish grin, Nicholson has returned to the screen like a roused tiger, delivering two electrifying performances that are destined to bring Academy Award nominations.With only three scenes, he dominates "A Few Good Men" as a Capt. Queeg-like commander caught in a Marine scandal. In "Hoffa," he plays the still-missing union leader at a high pitch throughout.

Two amazing jobs from an actor who considers himself "a phlegmatic person."

Nicholson rarely gives interviews and never for television - "They last so long; they rerun 'em and cut 'em just like movies and they show up everywhere."

The other day he sat down for a chat at his Mulholland Drive house high above Beverly Hills, with sweeping views of both the San Fernando Valley and "the only undeveloped canyon left."

He was outspoken, yet revealed no secrets, even about his often-distinctive love life. In earlier years Nicholson told all, including his use of drugs. But he's learned to hold back. Recent fatherhood also seems to have contributed a sense of responsibility.

Nicholson has a daughter, Lorraine, and a son, Raymond, both under 3, by actress Rebecca Broussard, 25 years his junior. The actor also has a daughter, Jennifer, 29, from his 1961-1966 union to actress Sandra Knight, his only marriage.

How often does he see his two youngest children, who live with their mother in the valley below?

"Every day," he replied, grinning broadly. "If I don't, I'm depressed. They're the greatest thing yet, so fantastic. Now when I have to go away or go to work, I go nuts. It's like a withdrawal. Every parent knows how I feel."

Nicholson lighted a cigarette and admitted, "I've always looked for some kind of emotionally stable plateau to quit (smoking), but I haven't reached it yet. I'd love to quit 'em on the babies' behalf. Many's the girlfriend who's told me, `I watched my dad smoke, and it looked so romantic; that's why I smoke.' I don't want to be that kind of a bad influence."

Even with consecutive flops - "The Two Jakes" and "Man Trouble" - Nicholson still commands top dollar from the studios. His reported $5 million for three scenes in "A Few Good Men" was calculated at $500,000 per day's work.

But that's not all. For 20 years, he collects his guaranteed salary and any overage by taking 5 percent of the gross - that's from the first dollar that passes through the box office. In the case of a superhit such as "Batman," his return can surpass $50 million.

"I always felt I make an easy deal; it's part of the business success that me and my guys have had," he commented. "I even got an overage check on `Going South' (which he directed) finally last year. I only say that because of my affection for my own work. I keep thinking, `Jack, you're 55 - grow up!'

"Nobody's been hurt (by his deals) that I know of. Maybe the `Man Trouble' people, because they were new at it, got hurt. I feel bad about that because I've never had to say it. My other `soft' pictures have been made at places where they made mountains of money on something else. It's not that many in my case, maybe one out of five."

Nicholson ruminated on a wide range of matters during the recent afternoon talk. Here are highlights of that interview:

Q. The young actors of "A Few Good Men" reportedly had an initial awe of working with you. Is that true?

A. (stammering) "I don't think I strike that in people. If I did, I am professionally good at disarming it. I knew a lot of these fellows and girls, so `awe' is not a word I'd pick out of the hat. . . . But if it existed, I would use it in a case like this. I wouldn't disarm it, I would it let it sit there. Because I think it would be right for (the role of fiery commander) Nathan Jessup.

"The same is true for Jimmy Hoffa. He is a guy who had a very strong aura as well. You see film of him in a room, he's a total dynamo."

Q. Did you watch film of Hoffa?

A. "I watched 80-90 hours, and I watched it over and over again. I never had this opportunity to actually look at the person I was playing. I think it brought something extra, an area that I never really went to before.

" `Hoffa' really shows the difference between film and theater acting. That performance couldn't be done consecutively on a stage. You've got to do it over a period of weeks, one piece at a time. I'm sort of a phlegmatic person myself, but this guy is like a burning, bristling house afire."

Q. "Man Trouble" was not a resounding success.

A. "No, but I didn't feel bad about it. I thought it was charming. . . . In all honesty, I think the movie was poorly handled. You got the people involved and the newspapers arguing about it. These days, everyone wants to be in the know about the movie business. It's amazing how resonant the smallest piece of insider gossip is. People who are far removed from the moviemaking scene, you'd think they were Darryl Zanuck the way they talk.

"The entrepreneur-impresario in me has always felt that it's been a long, big mistake getting the public involved at this level of how much a film cost and who's doing what. Filmmaking changes every year. The most outspoken people now are the executives. They used to be kind of silent but deadly in the background."

Q. Why did you become an actor?

A. "I drifted in. Once in, I just loved the job. There's one thing they can't take away from this particular profession: It is an ongoing education. You do go on learning about people, things, how the world works, what people are feeling. If you set people down, learning is really what they're after in life."

Q. Was there anything in your early life that inclined you toward acting?

A. "Nothing other than being in school plays, and there are dozens of people who did that. I started working in the MGM cartoon department to see movie stars, and I sort of drifted in. (Producer) Joe Pasternak asked me if I wanted to be an actor, and one thing led to another. I started studying right away, and it has always interested me.

"I've always loved the movie business and the people in it. I just think they're fabulous. I love the energy of it. I love it so much I'd be afraid to say so years ago; I might have jinxed myself. I'm 55-ish, and I can afford to feel incredulous about it."

Q. You've been sparing with interviews in recent times. Why?

A. "The reasons are: You say things you think are dumb, and now you've got to read it in the papers; you say something that you couldn't conceive that could hurt someone's feelings. Tonight I can guarantee you that when I lay down I'll think, `Now what the hell did I say to Bob? Is some wild thing going to go out and I'll have somebody call me on the phone?'

"It's not that you want to do or not do something. It's just a little bit out of your control. Acting people don't like to feel self-conscious, they really don't. I remember watching an interview with John Huston, and he was asked about his style. He said, `I don't think I have a style; if I thought I did, I'd feel self-conscious and couldn't go on working.' I thought that was particularly astute."

Q. Are you in good health?

A. "Excellent health. I went through all my yearly physicals when I got done working, and I even weighed in at exactly the same weight as last year. So I'm running on even right now."