IT'S HARD work being funny.

Harold Ramis knows. He has been writing, directing and acting in comedies most of his professional life. Hard work or no, he loves it.

"I've never pursued any aspect of my career at the expense of my fun potential," says the 38-year-old author of "National Lampoon's Vacation."

As a writer, Ramis, along with Lampoon alumni Chris Miller and the late Doug Kenney, made the toga party an overnight sensation in the hugely successful "Animal House." In other script collaborations he sent up the Army ("Stripes") and summer camp ("Meatballs"). He also played Ziske, Bill Murray's sidekick, in "Stripes." His directorial debut, "Caddyshack," a rambling mixture of star turns and comic business, was held together by the slimmest of threads but it, too, was a commercial hit.

Compared to "Caddyshack," Ramis' second directorial outing, "Vacation," is a seamless web. In it, the family vacation becomes a descent into tourist hell as Chevy Chase attempts to lead his family to the promised vacationland of Walley World. The film has grossed $43 million since July 29.

A Chicago native, Ramis began his career editing Playboy magazine party jokes. "What a job for someone in comedy," Ramis recalls. "I could read 1,000 jokes in one hour by scanning the punch lines." After a stint as associate editor at Playboy, he joined the famed improvisational comedy group Second City. When Second City took to a TV series he became head writer as well as actor. He wrote and performed in the "National Lampoon Show" on stage and acted in the "National Lampoon Radio Hour," which led to his Lampoon oeuvre on film.

Ramis is soft-spoken, with a raging Chicago accent, and looks like an over-the-hill graduate student with his wire-rim glasses and an air of bemused resignation.

Though it may be a trifle farfetched to regard "Animal House" or "Caddyshack" as political tracts, Ramis sees the theme in these films, the triumph of the underdog, as one firmly placed in Hollywood tradition, harking back to the films of the Marx Brothers, Frank Capra and even Walt Disney.

Q. "Vacation" is a hit movie. You must feel pretty good.

A. Oh yeah. Everyone's beaming at Warner Brothers. People are already auditing each other.

Q. You've written "Animal House," "Meatballs," and "Stripes," and directed "Caddyshack" and now "Vacation." Is leisure the major theme of Harold Ramis film?

A. Someone wanted me to play a tour guide in Africa. Then I was working on a resort comedy for Bill Murray. "Vacation" is just that. "Meatballs" is about summer camp. Even in "Animal House," these were students at leisure. They weren't exactly attending classes with any regularity. So I'd like to say it's accidental. But there are probably no accidents. Maybe subconsciously that's how I vent my own discontentment about work.

Q. Comic actors you've worked with like Chevy Chase and Bill Murray are beloved for their seemingly spontaneous bits of business and the characters they've created--even institutionalized--over the years. How do you direct them?

A. It's a series of agreements you make with them starting with the most general and coming down to the specifics of each moment.

Q. So you're making deals with them all the time.

A. I'm constantly negotiating my vision, optimizing what they do while realizing my intention.

Q. The scene in "Vacation" where Chevy Chase delivers a eulogy over poor Aunt Edna is a wonderful and crazy bit. How did you work with him on that scene?

A. With some people it's magic. We've created a moment: We know we've got this dead body and we're going to leave it, and his wife (Beverly D'Angelo) insists that he pray. My only problem then was having Chevy find something that he wanted to say and exploit some comic ability of his. He has always done this sermon character, the Church of the Confused or whatever it is. He likes improvising those things. But there were lines, some of which I insisted he keep. The danger with Bill or Chevy, people who improvise very well, is that they throw out all the scripted lines, including the good ones. The way to improvise and stick to the script is to block out the action into moments so you're not depending so much on what the words are but what the comic intention of the scene is. People like Bill or Chevy or Joe Flaherty are always trying to do better, always trying to improve. I worked with Joe Flaherty for two years on stage at Second City, six shows a week and he never did it the same way twice.

Q. Chevy Chase had his best role in years in "Vacation." He was kind of a Fred MacMurray gone mad.

A. I described him as a freaked-out Ozzie Nelson. And with Beverly I used to tease her by saying 'I need more Harriet here.' Sometimes I told her she was too June Allyson. Watching Chevy's other movies over the years, I realized he wasn't giving everything he had. I've seen him do "Lemmings" and I've seen him on "Saturday Night Live" and I don't know where his energy went. It seemed to be directed out of him somehow. I think he felt constrained and tired in the past. He's in great health, he moved to the beach, married. His wife became pregnant and he was feeling so paternal that he really wanted to do this part with all that energy.

Q. Is Clark Griswold Chase's character in "Vacation" a good father?

A. I really saw Clark as a guy who's trying to live up to an image of what fatherhood is. He really doesn't even come close to satisfying that image in regular life. Fifty weeks a year, he hasn't any time for the family and then in those two weeks he tries to give them everything. I always thought Clark was his own worst enemy. He's just a guy trying to be what he isn't. It has more to do with the way fathers see themselves these days and the way children see their fathers.

Q. Would you say "Vacation" is a more mainstream comedy than your other films?

A. The Lampoon, "Saturday Night Live," and these movies are what people perceive as the new comedy. But the people who do them know they are totally plugged into the mainstream of American entertainment. It's not a radical break with it, it's just a contemporary synthesis of it.

It's dangerous to talk about it but Doug Kenney thought he wanted to do hip Disney. I've always thought of doing very political Marx Brothers. Or Frank Capra. It's the only morality I can get behind. I think comedy without morality stops at a certain point. As simplistic as all the films I've worked on have been, they all have a simple Disney-Capra morality operating in them because that's what I grew up with. In Capra films the common man triumphed against the hypocrisy of people with power. All the good guys in "Caddyshack" represent the middle and lower-middle classes fighting the snobbism of the country club system. The same thing is operating in "Animal House."

Q. Are country clubs, camps and campuses institutions just waiting to be knocked down just as Margaret Dumont or the opera or the aristocracy were waiting to be knocked down by the Marx Brothers?

A. The Thirties were really alive politically, and anyone who represented the disadvantaged in that society at the expense of the upper classes, who made buffoons of the rich and powerful was "a red." The tradition of liberalism and radicalism in Hollywood has always been there. There were political elements that always thought Hollywood was deeply subversive and controlled by Jewish leftists. I think they bided their time until the McCarthy era . It's not so true today because the people who control the media have become so skillful at co-opting ideas and making them commercial. And the Sixties expanded everyone's notion of what was tolerable, of how much dissent we could really survive without coming apart. Now you get a studio like Paramount making "Reds" and actually believing that it might pay off commercially. If someone had suggested making that film in 1952 they would probably have never worked again. Every institution is vulnerable to a realistic analysis of what's really going on. I have a child and it makes me look back and think about what I was taught, about what is reality. When you're taught to believe that the police are in control, you get cynical as an adult when you realize the police are just trying to stay alive themselves and that criminals are actually doing much better than the police. Crime is a much more profitable institution laughter . Some institutions are more important to talk about and others are more fun to talk about.

Q. Can you discuss your life as a director versus that of your other fields of activity such as acting and writing?

A. I didn't think I would be a happy person if my life depended on whether I was acting or not. Fortunately, I had other work. Most actors act because they can't do anything else. Directing is the synthesis of those things. The thing about being a film director without experience is that I know what I'd like to see in the picture without actually having to operate the camera. I never had to go through that stage: someone placed the technology in my hands. I knew nothing and I didn't think it was safe to walk onto a Hollywood set full of professionals with the combined experience of 1,000 years and act like I knew anything. On "Caddyshack" they'd ask where do you want the camera and I'd say, I don't know, what do you think? And then we'd discuss it.

Q. Was "Caddyshack" a directorial baptism by fire?

A. I was groping in some ways. It was controlled by elements I couldn't change. The actors weren't a problem, oddly enough. We'd written too much story. Bill Murray's part was totally improvised. Also we found ourselves on a location that was a bit like buying a piece of swampland in Florida. They had showed us a country club on a particular time of day on Sunday, and we thought it was fabulous. And when we got there to shoot we found out there was active condo construction on three sides of it with bulldozers, cranes, everything. And we were on the approach to Lauderdale International Airport, so at midday 72,000 airplanes would come in under 2,000 feet while we were tracking dialogue. By the time the planes left the clouds had gathered for your Florida midday rain. And it rained the 15 days of our shoot. I could have done better.

Q. You've worked with many of the performers from SCTV and "Saturday Night Live." Do you think they are fulfilling their promise in films and what about the performers we never see in films?

A. I think they'll all work for a long time. I think Andrea Martin will be great somewhere because she's great every time I see her. Catherine O'Hara and Marty Short will find great things to do. Now I look at talk shows, and people that I knew a long time ago have replaced the pontiffs of the last generation. It's like suddenly you realize the cops are younger than you.

Q. Will you always work in comedy?

A. I don't know what would change my mind about life being funny. I've seen so many terrible things and I still want to do comedy. You want the audience to laugh. And to actually get a laugh you have to almost physically move them. When I watched a screening of "Vacation" to evaluate parts of the film for editing I was sitting behind the audience and I realized I wasn't in a great place to hear the full volume of their laughter. Then I realized I could just look at their shoulders and heads and tell when they were really involved. I could see that they would actually pitch forward during certain lines of the film. I knew where the laughs were and it was an interesting lesson in just how physically involving comedy is. You really have to work hard for a laugh.