With a new version of Regina George and the Plastics headed to theaters, she reflects on how different generations have reacted over the years.Tina Fey spent the summers of 2002 and 2003 hunched over an old desk in the mildewy back room of a Fire Island rental home. Fueled by coffee and Entenmann’s chocolate-covered doughnuts, Fey, at the time the head writer for “Saturday Night Live,” cracked the script that became “Mean Girls” on her laptop.“She would old-school just sit and eat doughnuts and drink coffee, like a secretary from the ’50s or something,” said her husband, the composer Jeff Richmond. “Not glamorous but very conducive to creativity.”In the two decades since, Fey has turned her first and only released screenplay into an empire. The original Paramount film, based on Rosalind Wiseman’s nonfiction book “Queen Bees and Wannabes,” earned $130 million during its 2004 theatrical run and helped make superstars of its cast, which included Lindsay Lohan and Rachel McAdams. In 2018, a musical stage adaptation with a book by Fey and music by Richmond, opened on Broadway. In June, that show will begin its West End run. And this week, a movie musical adapted from the past iterations, and written by Fey, arrives in theaters.(Last March, Wiseman criticized Fey and Paramount for not involving her in the subsequent versions. When asked about the criticism, Fey said she had no comment.)But beyond the commercial success of “Mean Girls,” Fey’s endlessly quotable script — “You can’t sit with us”; “The limit does not exist”; “I’m a cool mom”; “Stop trying to make ‘fetch’ happen” — has embedded itself in our culture.“It became part of my vernacular, every single sound bite,” said Samantha Jayne, who directed the newest “Mean Girls” with her husband, Arturo Perez Jr., and was a teenager when the 2004 original came out. “It was in my DNA.”The 2024 movie mostly follows the characters and story that audiences know by heart, with the addition of singing and dancing: New kid Cady (Angourie Rice) teams up with outsiders Janis (Auliʻi Cravalho) and Damian (Jaquel Spivey) to take down the vicious Regina George (Reneé Rapp) and the Plastics, until Cady, too, gets swept up in their hurtful ways. Fey and Tim Meadows reprise their original roles as Ms. Norbury and Mr. Duvall, and there are still Mathletes, a Spring Fling and pink shirts on Wednesdays.“High school is the one remaining American experience that everyone has,” said Lorne Michaels, a producer of the new film along with Fey and others. He and Fey have worked on every version of “Mean Girls,” apart from a widely panned 2011 TV film. “It’s just a central, iconic thing.”But high school, and the nature of comedy itself, has evolved, onscreen and off. Now, rumors spread on social media. Viral videos are uploaded to TikTok. In the film, Coach Carr (Jon Hamm) no longer has sexual relationships with underage students, and North Shore High doesn’t have cafeteria cliques defined by race. With each “Mean Girls” iteration, Fey has tried to keep her script razor-sharp yet relevant and palatable to new generations and zeitgeists.“As long as I don’t accidentally make Monkey Jesus out of it — you know, like when that lady tried to fix that painting — then we’ll be in good shape,” Fey said.In a recent video interview, Fey discussed her more-than-20-year journey with the material and what’s next. These are edited excerpts from our conversation.Bebe Wood, left, Rapp and Avantika in the new film, which has evolved to reflect how new generations spread rumors.Jojo Whilden/Paramount PicturesWhat was your original vision for what a “Mean Girls” movie could be when you read that 2002 article about Wiseman’s book and teenage relational aggression?I first imagined, Oh! It’s going to be about this teacher. It’s going to be like “Stand and Deliver.” And the more I read the book, the more research I did, [I realized] the girls were the most interesting part. The true stories of the way young women behaved were insidious, but they were also kind of funny in their vicious cleverness.How has your technical writing process changed over the years?The rookie mistake I made was, I asked to adapt a nonfiction book that did not have a story. I had these amazing behaviors and anecdotes, but I didn’t have characters or story. So, I literally read Syd Field, read “Save the Cat,” had a million index cards. And then the switch to the stage, on a technical level, you’re taking a three-act thing, and you have to break it into two acts. You don’t have voice-over, you don’t have close-ups. Things have to play in the balcony. Now, with the movie musical, you can have all the things in your arsenal: You can play things with just people’s eyes. You can have people sing about their emotions. Jokes can be big and visual, or they can be Easter eggs.As someone who was in high school in 2004, seeing the tagline “This isn’t your mother’s ‘Mean Girls’” in the musical movie trailer was a shock.That came from the Paramount marketing department. I want to comfort millennials by telling them that’s just an expression in the English language. And also, when the movie came out, some people who were older than you also went to it. Some people as old as 26 or 27 may have been in the theater with you.Much of the comedy in the original “Mean Girls” has held up incredibly well. But there are some jokes and story lines about race, sexuality and pedophilia that haven’t, and they were altered for later versions. How do you approach updating your writing?I was writing in the early 2000s very much based on my experience as a teen in the late ’80s. It’s come to no one’s surprise that jokes have changed. You don’t poke in the way that you used to poke. Even if your intention was always the same, it’s just not how you do it anymore, which is fine. I very much believe that you can find new ways to do jokes with less accidental shrapnel sideways.The original film, with Amanda Seyfried, left, Rachel McAdams, Lacey Chabert and Lindsay Lohan, reflected Fey’s experience as a teenager in the ’80s.Paramount PicturesName calling is central to “Mean Girls,” and the way that they throw these barbs — —If we really had people speak to each other the way they spoke to each other in 1990, everyone would go to the hospital. People were really rough. People are still horrible, they’re just more likely to anonymously type it. I would like to take but not teach a graduate school class on the ways in which people are just as divisive and horrible as they ever were, but now they couch it in virtue.There are specific word changes throughout the new script. Like in the Burn Book, Dawn Schweitzer is now called a “horny shrimp” instead of a “fat virgin.” What goes into choosing those terms?I know that even Regina would know what wouldn’t fly. She’s going to find a way to inflict pain on people, but she’s not going to get herself in trouble. For example, there’s a joke in the original movie when Janis gets up on the table and Regina says, “Oh my God, it’s her dream come true: diving into a huge pile of girls.” It was mine and Sam Jayne’s feeling that Regina wouldn’t try that now because she knows the kids around her would be like, “That’s homophobic.” She would know not to be homophobic, and hopefully, truly would not be homophobic.I was waiting for Ms. Norbury’s speech telling the girls to stop calling each other “sluts” and “whores,” and it didn’t happen. But I realized they weren’t calling each other those words much in this script anyway.Some of that was just needing to go faster to make room for songs. That one is not necessarily a moral edit.Gen Z has seen body positivity and body neutrality movements. When Regina gains weight in the movie musical, the other students’ initial reaction is positive — but then she’s still shamed. Why was it important to have weight still be an issue here?Look at the famous people that influence Gen Z, and we’re still always talking about their bodies. We’re either attacking other people for talking about it, or commending people for being a size, or we’re questioning how they got to a different size. It felt like a line to figure out. We still want to be talking about how weird and messy everything is for girls, while acknowledging that these standards aren’t mandatory — but a lot of people are still signing up for them.Were there any cultural shifts that you saw in updating the script from the 2018 stage show to now?If anything, these behaviors have jumped way beyond just young women. It’s in our politics. It’s in everything. People now like to candy-coat and be very virtuous pointing out why you’re a problem, but it’s the same behavior. It’s still, “Don’t look at me. Look at them. I’m doing great. I might not have nice hair, but she’s fat.”We learned so much with the [stage] show that there doesn’t have to be rigidity in the casting of these roles, in terms of what they look like and how they identify. This story works in many interesting permutations. Anyone with charisma is a good Regina. Anyone who looks like they might come apart can be a great Gretchen.How do you stay in tune to what the teens are doing today? Is that through your daughters, Alice, 18, and Penelope, 12?I did poll some young people I know, including some young people that live in my house. Things like, “Should the Burn Book be a physical book or does it have to be a Snapchat or something?” They were like, “No, don’t pander to us. It’s a book. Tell the story. We get it.”Have you toyed with the idea of doing a sequel that brings back the original cast to play their characters as adults?I have a feeling Paramount would love that. I have not really thought much about that. To me, part of why the stakes are so high in the story is because everyone’s so young and feelings are huge, love is huge and friendship is huge in a way [that it isn’t with] middle-age moms. I love writing about middle-aged people, but I don’t know.There were reports that you tried to get all four of the original main actresses back in small roles in this film. What would that have looked like?We’ll never know. They’re busy people, so it didn’t come together, but we tried, and we all love each other.What’s the appeal of going back to this material again versus doing something different?I have other things that I’d like to do. But I have so much gratitude that this movie seemed to stick with people. When I look at it, I am reminded of how hard I worked on it in the first place. I feel like the bricks and mortar of it were the absolute best possible job I was capable of at the time. It’s not perfect, but it holds water. More