Wallace Shawn, Mr. Hall: That is Hollywood. The director is far from being the sole decision-maker. Even if she’s also the writer, she’s not the financial backer, so … I think you have to cooperate with a lot of other people. If all the Paramount executives had said, “We don’t like him and we want you to use so-and-so,” she would have had to do that. I don’t think I was brought into the process. She was certainly not keeping me posted—she probably did all that and then said, “Come play the part.”

Nicole Bilderback, Summer: When you’re reading the script, when you see dialogue on paper, you think, Oh, O.K. This is fun. But back then, before the movie was released, when you read lines like “What-ever,” you’re like, O.K., what is this?

I actually read for two parts: I read for Summer and for Heather, and they liked me for both, but they ended up casting me as Summer.

The girl who ended up getting the role of Heather may have been in the waiting room [when I auditioned].

Susan Mohun, Heather: I had a few different auditions, and I don’t think I’m supposed to name names, but my final audition was with Paul Rudd and a famous actress’s daughter who seemed to be very good friends with Amy Heckerling. I had a 104 fever and had gone in the hospital, but decided I was just going to go for the heck of it to the final audition. I was sure that I wasn’t going to get it because I was really sick, and this other girl, who looked exactly like her very famous mother, seemed to have it in the bag. So that was a surprise to get the role—and very exciting.

I didn’t realize, obviously, that 20 years later we’d be talking about it.

Paul Rudd: After the table read we all went and got a bite to eat. We went to a place not far, around the corner, that I used to go to, which was kind of a bar. They probably should not have let some of those kids in. I do remember all of us sitting around saying, “How cool is it that we’re all going to do a movie about kids our own age?” And having that conversation about the John Hughes movies to our generation. It had been a while since there was one of [those]—“How cool would it be if this thing had legs?”

Then it kind of did.

The Critical and Box-Office Success of Clueless

During its opening weekend, in July 1995, the film played in 1,653 theaters across America and quickly proved that Paramount Pictures had a sleeper hit on its hands.

After that first weekend, Clueless would go on to earn $56.6 million. It was, without question, a game changer for every single person who worked on it, both on-camera and off. For members of the cast and crew, the film placed a noteworthy credit on their résumés and, often, swung open the doors to opportunities in Hollywood that they could not access before. When a film becomes a hit and, as Clueless did, a cultural phenomenon, the actors and artists behind it quickly realize that their association with it will attract a lot of attention. What those same actors and artists couldn’t possibly have known in 1995 is that 20 years later attention would still be paid.

Adapted from As If!: The Oral History of* Clueless, *as Told by Amy Heckerling, the Cast, and the Crew, by Jen Chaney, to be published next month by Touchstone, a division of Simon & Schuster, Inc.; © 2015 by the author.