LOS ANGELES (AP) _ Sipping champagne and looking uncomfortable, Jack Nicholson leaned against the bar at the Academy Award nominees luncheon and surveyed the media clamor that greeted the famous arrivals.

''This isn't my sort of thing,'' he muttered. ''I'm doing it for Anjelica.''

Anjelica is Anjelica Huston, the love of his life. John Huston is her father. The Hustons and Nicholson were all nominated for their work in ''Prizzi's Honor,'' a film for which Nicholson has made himself uncommonly visible.

''I'm really devoted to that film,'' he said.

Nicholson is no stranger to the Oscar, having been nominated eight times and winning twice - as best actor in ''One Flew Over the Cuckoo's Nest'' (1975) and best supporting actor in ''Terms of Endearment'' (1983).

''This year is different,'' he said. ''This is the first time I've known all the other guys personally. And they all were great. I couldn't begin to predict which one is going to win.''

Neither can veteran Oscar seers.

The field: Nicholson as the oddball hit man of ''Prizzi's Honor''; James Garner, the mellow druggist of ''Murphy's Romance''; William Hurt, the gay movie fanatic of ''Kiss of the Spider Woman''; Harrison Ford, the hardbitten Philadelphia cop in ''Witness''; Jon Voight, the demonic escapee in ''Runaway Train.''

Voight won as best actor in 1978 for ''Coming Home.'' Hurt, Ford and Garner are first-time nominees.

''I guess I made it look too easy all along,'' mused Garner at the nominees luncheon in the Beverly Hilton ballroom.

Customarily a modest man, the Oklahoma-born actor obviously enjoyed being recognized by his peers after three decades in films. ''All these years folks have been saying, 'Good ole Jim, he'll come through, but we can't really take him seriously as an actor because he's just playing himself.' Well, now maybe they believe there could be a little skill involved,'' he said.

A surprise guest at the nominees luncheon last week was William Hurt, who ordinarily shuns public events. Like Nicholson, he avoided running the gauntlet of media interviews.

During one of his few interviews, Hurt commented: ''I'm a character actor in a leading man's body. I want more mask than, say, Spencer Tracy did. But I don't 'pretend' to be somebody else. Acting isn't schizoid like that. Acting is about telling the truth. And it's an adventure. It isn't about what I know before I do it. It's about what I can discover while it's happening.''

Harrison Ford was the only best-actor nominee who didn't appear at the luncheon. He is in Belize filming ''The Mosquito Coast'' with Peter Weir, who directed him in ''Witness.''

As Han Solo in the ''Star Wars'' trilogy and as Indiana Jones, Ford has appeared in more blockbuster movies than any other star. But like Garner, he had to wait before the movie community recognized his acting skills.

As the detective in ''Witness,'' Ford has a wider swing of emotions than in his action films, thus attracting Academy votes.

''Yes, you might say there's more range in 'Witness,' but that's the easy part,'' he said in a recent interview. ''When you have more range, it's far easier to seduce an audience because you have more tools to work with. The more limited the character, the greater the challenge. For instance, how much does anyone know about the family background of Indiana Jones?''

Jon Voight drew his third nomination with a change of direction. Often a portrayer of sensitive characters in dramas, he switched to the heartless convict in the action-filled ''Runaway Train.''

''Except for 'Deliverance,' I haven't done any action pictures,'' he said. ''And in 'Deliverance' we had an actor who has made a good living from action pictures - Burt Reynolds.''

Voight reflected on his own Oscar and how winning affects an actor's life and career.

''My own son, who is now 12 years old, told me beforehand, 'Dad, you're going to get a lot of attention if you win the Academy Award - that night and the next day. But after that, they're not going to care too much. After that, they're going to be more interested in next year's race.'

''That's about what happened,'' he said. ''You get a lot of attention, and everybody thinks you're terrific. But a week afterward, the attention is on next year.''