For Fritz Weaver, acting and life interlock. Experience enriches roles; roles can complicate living

He has played such tragic Shakespearean roles as Hamlet, Macbeth, and Richard II, but the real Fritz Weaver may be the one who turns up for an interview wearing palm tree socks. He waggles his ankles, showing off the big green palm trees printed on them. The socks were a joke of a gift from a dear friend, he explains, to celebrate the opening night of ``Sullivan & Gilbert,'' in which Mr. Weaver stars as Victorian wordsmith William S. Gilbert. The new Ken Ludwig play, with music by the famous operetta team, is dishing up some merriment at Kennedy Center's Eisenhower Theater through Oct. 9.

Weaver, who manages a little soft-shoe as well as singing in the show, has done his share of that previously in ``Baker Street'' and ``My Fair Lady.'' Melding the play and the music is less demanding here, he says, because, in the scene where he plays Gilbert directing a rehearsal, ``I'm sort of teaching the company how to do things, and so it's easier to integrate.'' Weaver says Rex Harrison, father of his co-star, Noel Harrison, ``taught a whole generation of actors how to get up there and not sing - talk your way through a song. So I think that's what made it possible for people like us to dare to get up as professional singers.''

The actor's face, familiar from such films as ``Marathon Man'' and ``Power,'' is garnished with gray mutton chop whiskers for this role. He looms 6 feet, 3 above those palmy sox - a commanding presence with a full head of pewter-gray hair, fine features, and navy blue eyes. His deep voice, steeped in Shakespeare, has a burnished tone. He is one of those accomplished actors who can make ``Would you care for a cup of tea?'' sound like the start of a soliloquy.

Weaver, who won a Tony Award for his performance in ``Child's Play,'' has had some juicy roles in his career. The first part he ever played was one at the University of Chicago that lured him away from his physics major and into the theater. It was the part of Thomas `a Becket in T.S. Eliot's tragedy ``Murder in the Cathedral.''

Playing that role ``does set you up for life,'' he says, ``because, when you play the great roles, you get spoiled and think you'll have a whole career playing nothing but great roles, and of course you can't. It's the wrong thing to start on, because it gave me a false idea of the circumstances of our profession. You play a lot of junk most of the time. Television is junk, most of it.'' He can't resist growling about ``situation comedies, turned out like ground meat, and the cynical manipulation of the audience.''

The reverse of that, for him, is the thrill of doing Shakespeare. (He will be performing a certain Shakespearean role after ``Sullivan & Gilbert'' closes, but it can't be discussed yet.) ``The old boy - he's the one who makes the maximum challenge to the actor. That high charge on all the lines that he writes - you've got to measure up. You can't just saunter into that stuff; you've got to bring your whole life into it.''

Sometimes a Shakespearean role will cast a shadow on the actor's life, as Weaver found when he played Macbeth and Hamlet at Stratford, Conn.

``Macbeth is a character I never should have played. I began to dislike him halfway through the rehearsals. ... He's a killer, a coldblooded killer - he and his wife. And I think Shakespeare was interested to see the breakup, the cracking up, of a character and demonstrated it quite well.

``I almost cracked up playing it. I tried to make the audience understand the deterioration of a soul.'' He mentions that Dame Edith Evans, the great English actress, was once asked why she had never played Lady Macbeth and explained, ``Oh, I never really understood all that evil.''

But of Hamlet, he says, ``There's the part of all parts. It's the part you almost can't fail in.'' He pauses. ``If I were playing it again....'' He smiles. ``Unfortunately you get ruled out by age from playing these parts. When you're beginning to know something about how to do it, it's no longer in your range. But you still wake up in the morning thinking, `I know how to play that moment now.'''

Weaver admits that some of his favorite Shakespearean roles and the tragic priest in Graham Greene's ``The Power and the Glory'' stay with him like a poem, and he continues to work on them in the theater of his mind.

Among the toughest roles an actor has to play offstage is that of award winner, Weaver suggests. He says winning a Tony did not act like a rocket on his career. ``What I remember is a vast silence from the phone, because people said, `We won't offer it [a role] now, because we can't offer him enough money.'

``I've heard this from dozens of people. The last one, I think, was Anthony Quinn, who told me, `Oh, I hope I never win another Oscar. It's like having an anvil around your neck. You drag it around for a year until people fortunately forget you won one.'''

Weaver, born in Pittsburgh, is a New Yorker who has been separated for several years from his wife, actress Sylvia Short. The couple have two grown children: writer Lydia Weaver and actor Anthony Weaver. ``And they're both very talented, he said without a trace of subjectivity,'' Weaver adds with wry pride.