Amy Heckerling’s “Clueless,” a riff on the Jane Austen novel “Emma,” starred 18-year-old Alicia Silverstone as Cher Horowitz, a Beverly Hills teenager who ruled her high school with equal parts charm and obliviousness — and a whole new lingo. Co-stars Stacey Dash, Donald Faison, the late Brittany Murphy and Breckin Meyer were all key players, as was a then-unknown love interest by the name of Paul Rudd.

Murphy, who mysteriously died of pneumonia complications and drug intoxication in 2009 at 32, played a key role in “Clueless” as newcomer Tai. “It just breaks my heart — I can’t make heads or tails of it,” Heckerling says of Murphy’s death. “It didn’t make any sense. It still doesn’t.” Twink Caplan, an associate producer on the film who also played the delighfully daffy teacher Miss Geist, says everyone on set adored Murphy. “She would have loved that this movie was so big,” Caplan says. “It made her immortal.”

Released on July 19, 1995, the movie kicked off a glut of Austen adaptations and gave us quotable quips (“You’re a virgin who can’t drive!”) that made the film a timeless classic.

“Girls and women all over the world respond to the movie to this day because the characters have this sense of themselves,” says costume designer Mona May. “Even though Cher had flaws and was self-centered, her actions come from trying to improve the world as she’s improving herself.”

In honor of the film’s 25th anniversary, Heckerling, Caplan and May share their favorite “Clueless” trivia.

The screenplay initially faced pushback for having a female lead.
Director Amy Heckerling: [“Clueless”] was originally in development at another studio, and there was a lot of resistance to having a main character being a female. That meant that you would have a smaller audience and less of a budget.

In Heckerling’s utopian Beverly Hills, there was “no racism.”
AH: It was always my desire to create an alternate universe where there’s no racism, everybody is having fun, everybody has money to buy things. When somebody comes in from the outside, they take her under their wing and dress her up. That isn’t the real world. The high school we shot in, [Ulysses S.] Grant HS, had just had a shooting a few weeks before.

Cher’s high school is named for Louisa May Alcott’s dad.
AH: I was named after Amy in “Little Women.” And I was seeing Bronson Pinchot at the time. I found out his middle name was Alcott! He was named for Bronson Alcott, who was Louisa May Alcott’s father — one of those free-thinkers. He was very into women getting an education.

Costume designer Mona May wasn’t a fan of the fashions of the film’s era.
MM: [The style] was all grunge then, and kids looked horrible. This was really the antidote to that. What Amy wanted to do was not only have high fashion be almost a character in the film, but that it be transformed through the eyes of the girls. There wasn’t a lot of money, so I was taking the high fashion and pairing it with something from the mall. Now, that’s [de rigueur] — the $5,000 purse with ripped jeans.

The screenplay’s sassy slang came from a wide range of sources.
AH: There was a professor at UCLA who would get together linguistics students and compile a list of slang. That’s where “she’s a Monet” came from. There was ethnic slang, rap music slang. I put in some Yiddish: When Dionne is happy that boys were responding to Tai, she says she’s kvelling. For Christian [played by Justin Walker], there had been a resurgence of 1950s Rat Pack stuff, clubs with swing dancing. Cab Calloway published a jive talk dictionary I used.

Actress Twink Caplan: Amy’s dialogue should be anthologized. Like when they’re talking about virginity and Cher says, “You see how picky I am about my shoes, and they only go on my feet!” Or someone is “hymenally challenged.” I used to say Amy was the female Woody Allen, but he’s getting so much flack, I can’t anymore.

When Silverstone mispronounces “Haitians” in her debate speech, that isn’t acting.
AH: The first day, we started with Alicia’s Haitians speech. I ran around to everybody that was trying to go up and correct her pronunciation and [stopped them]. I felt like she had a certain confidence in the way she was saying it.

The crew loved Paul Rudd’s kiss scene.
AH: He could be vulnerable, he could be a nerd, he could be the stud, he could be a hero, he could do anything. When we were shooting the scene with Alicia and him right before they kiss — which I had rewritten 500 times — the crew would say to me, “Oh, that’s a good scene.” I was like, “Oh, it is?” The big guys carrying all the equipment around are saying they liked it because it’s romantic!

Donald Faison, as Dionne’s boyfriend Murray, had a big first on the set.
AH: When we finish the freeway scene, and Murray kisses Dionne because she’s all nervous, and they’re happy to be alive — that was Donald’s first screen kiss. When I said “cut,” he just jumped around the set like crazy. He was bouncing around like a puppy. God, he was happy and proud.

The freeway-freakout scene was inspired by Heckerling’s own phobia.
AH: I have issues with driving. I got my license after failing the test five times, because I was too nervous. Every so often, in LA, you’ll find yourself in a lane that just turns into the freeway. When that happens, I keep screaming until I get off again.

Heckerling makes a cute cameo at Miss Geist’s wedding.
TC: I love Amy, which is why I forced her to be my bridesmaid in the movie. When I threw the bouquet, they weren’t going at it enough, so Amy had to get in there and push everyone around. There’s a shot of her pushing everybody.

“Clueless” will always be a go-to for teen girls.
MM: Girls and women all over the world respond to the movie to this day because the characters have this sense of themselves. Even though Cher had flaws and was self-centered, her actions come from trying to improve the world as she’s improving herself.