ROBIN WILLIAMS is outrageously funny, the king of improv, the emperor of free-wheeling comic riffs. You can be talking with him and suddenly he's out there somewhere, talking to you like a Russian ballet master, or a Brooklyn mechanic, or an English nanny.
Mr. Williams's imaginings take him where few comics have gone before. The public obviously enjoys the trip, because his 20th Century Fox film, ``Mrs. Doubtfire'' has earned $200 million, making it second only to ``Jurassic Park,'' as the largest-grossing film of this season.
What makes this success doubly sweet is that ``Mrs. Doubtfire'' is the first film for Williams's Blue Wolf Productions, and the initial project which his wife, Marsha Garces Williams, produced.
The actor describes his process: ``I always stay with the script for the first take. Then, I'll make suggestions. Usually the director will say, `Go for it,' and it's like channeling. I'll start improvising with the role. Sometimes I go a step beyond, and it really works, sometimes it doesn't.''
When he did the voice of the Genie in Disney's ``Aladdin,'' he tried a variety of approaches. ``I went in and gave them a dozen different voices and accents. Which? They said, `You do anything you want.' So we were strapped in for 30 hours of taping, which they could edit to 30 minutes. When I left the studio, there were still one or two lines from the original script. My premise was: `Rub the lamp, I'm here, let's play.' ''
Last season, Williams starred in an episode of the TV series, ``Homicide,'' based on events taken from police files in Baltimore. In the segment, he and his children see his wife murdered. He never changed one word of dialogue. ``There was no need, it was real.''
Filming ``Mrs. Doubtfire'' was different.
There was plenty of ``let's try this,'' Williams says. ``With Marsha producing, I had someone right there who knows me so well, and who could rein me in, or let me go....''
``I think the roots go back to my being an only child. Imagination becomes your friend,'' he says. ``At one time, I lived in a huge house where there weren't any neighbors. I had to entertain myself, so I created a world. In Detroit, I went to a very straight all-boys private school.''
Then in 1969, the family moved to Marin County, just north of San Francisco. ``I was exposed to this wildly strange new world.''
At 18, Williams took an improvisation class that triggered his eventual career. He spent three years at Juilliard Academy in New York, where his teachers included John Houseman. He has won two Emmys, four Grammys, and three Best Actor Academy Award nominations - for ``Good Morning, Vietnam,'' ``Dead Poets Society,'' and ``The Fisher King.'' (Although he's not up for an Oscar this year, ``Mrs. Doubtfire'' has been nominated in the makeup category.)
Williams and his wife loved the children's novel, ``Alias Madame Doubtfire,'' by Anne Fine, but they wanted to avoid turning the film into just a silly romp with Williams masquerading as a Scottish nanny.
When director Chris Columbus suggested building up the father-children relationship, it made sense: a divorced dad, who loves his children so much he'd even take a job working for his ex-wife so he could be with them.
``In the first draft of `Mrs. Doubtfire,' the script had the family get back together. We changed that. In the world I know, that's not the case. Kids whose parents divorce have major [problems] ... knowing what's going on ... asking `Why are you doing this?' ... or self-blame, telling themselves it's their fault. Any divorce is painful for the kids. This is the world, the kids are ciphers - they pick up whatever goes on, you've got to realize this and respect it. That's what we wanted to do in the film.''
WHAT'S next for Williams? ``It's a movie that I filmed before `Doubtfire,' and Warners is releasing it this spring. It's called `Being Human' and I play five different characters spanning 6,000 years.
``I go from cave man to Roman slave to medieval Crusader, to 16th-century Portugese colonist to present-day New Yorker. They're cerebral transitions that have to be tweaked just right. It underlines [the idea that] whatever the time or place the basic problems are the same.''
There has been talk about Williams doing ``Batman III.'' He doesn't directly answer the question, but admits, ``The possibilities are endless - just imagine The Riddler as a hacker messing with the information highway.''