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It’s been 20 years since J.K. Rowling’s magical novel “Harry Potter and the Sorcerer’s Stone” hit U.S. bookshelves, and since then, Rowling’s story of the boy who lived has inspired a film franchise, touring exhibits, concerts, and amusement parks.

But the first reimagining of the Wizarding World came in the form of Chris Columbus’ 2001 film, named after and based on the first book in the series. The rest is public history. Young Daniel Radcliffe, Emma Watson, and Rupert Grint shot to superstardom as Gryffindor’s golden trio, instilling hope in the hearts of muggle children everywhere waiting for their acceptance letters to Hogwarts.

In celebration of the “Sorcerer’s Stone’s” 20th American anniversary, 10 behind-the-scenes nuggets have been compiled, as golden as a snitch on the Quidditch pitch.

Radcliffe didn’t seek out the role of Harry

While thousands of kids auditioned for the coveted role of Harry, Daniel Radcliffe went on a trip to the theater with his father. Serendipitously, “Sorcerer’s Stone” producer David Heyman and screenwriter Steve Kloves happened to be sitting in the row in front of the Radcliffes when the young boy with dark hair caught Heyman’s eye. “This person had this quality, this old soul,” Heyman recalled in an on-set interview. “I realized that this boy had something very special — had the quality we were looking for.”

But Grint certainly fought for Ron

Like many young readers, Grint was enamored with the Wizarding World. Though his acting resume only included a school play, he wanted the role of Ron the minute he saw the open casting call, so he submitted a video to the casting directors with three key components: an impersonation of his female drama teacher, plus a rap and speech about why he would be the perfect Ron. In the end, Grint’s determination paid off.

Rosie O’Donnell begged Columbus to play Mrs. Weasley

Grint wasn’t the only person who had his eyes set on a member of the Weasley family.

During her interview with the young cast, Rosie O’Donnell revealed that she called Columbus begging to play Ron’s mother, Molly. Though O’Donnell joked that she offered to take the role for free, Columbus’ strict British-actors-only policy made her ineligible for the part, which eventually went to Julie Walters. “If we want to make this movie the way it should be made, it has to be an all-British cast,” Columbus recalled thinking in an interview with Katie Couric.

Production designers built the Great Hall from scratch

Though much of Hogwarts was constructed with plaster, the Great Hall really is as majestic as it appears onscreen. The “Sorcerer’s Stone” production designers modeled the Potter films’ signature set after the dining hall of Christ Church College in Oxford, complete with the same massive physical dimensions and York stone flooring, according to the special features on the extended edition of the first film.

The filmmakers did try to give Harry his mother’s eyes

Ask Potter fans what their issues with the movies are, and they’re likely to mention Radcliffe’s natural blue eyes, which are not at all like Harry’s green eyes in the book (or like his mother’s, which is important to the Potter plot). But true fans may already know that the “Sorcerer’s Stone” filmmakers actually tried to stay faithful to the source material by giving Radcliffe green contact lenses, which they eventually scrapped after Radcliffe had an allergic reaction to them. They also gave up on Hermione’s prosthetic buckteeth, which prevented Watson from delivering her lines clearly.

Steven Spielberg was in the running to direct

Not surprisingly, Columbus wasn’t the only director who had his sights set on Rowling’s seminal books. Several established filmmakers sat in for interviews with Rowling, who has famously kept a tight hold on the world she created. According to a report by Couric, even Spielberg was in the running at one point. But in the end, Columbus bested them all. “I think they really wanted to know that I would be faithful to the material,” he told Couric.

The kids had fun pranking the adults on set

They may have beat out thousands of hopefuls for some of the most coveted roles in cinematic history, but at the end of the day, kids will always be kids. Radcliffe, Watson, and Grint often entertained themselves on set by pranking their A-list co-stars, including Robbie Coltrane, also known as Hagrid, who was reportedly not too pleased when they reprogrammed his cell phone to Turkish.

Real owls were used as  messengers — lots of them

No one can forget the visuals of every species of owl bombarding Privet Drive with Hogwarts acceptance letters. Carrier-pigeons of the Wizarding World, the sharp-eyed birds were often important vehicles for advancing the Potter plot, with Harry’s snowy owl, Hedwig, in the featured role. And, as revealed by Columbus in an on-set interview, 80 percent of the owls seen in “Sorcerer’s Stone” were real. “Obviously, we didn’t fill this room with owls, but we did do several shots with real owls delivering mail,” he said. “We added some CG owls to fill the room because you couldn’t — in terms of training these owls — you couldn’t get more than a few in at a time because they would start running into each other.”

Richard Harris’ granddaughter threatened him when he was offered the role of Dumbledore

Though the Potter stories center on children, several seasoned adult actors stepped in to fill out the supporting cast of parents, villains, and professors, including Harris, Coltrane, Maggie Smith, and the late Alan Rickman. And perhaps the only people more excited about their casting than the actors themselves were their young relatives — especially Harris’ granddaughter. “My granddaughter called me, and she said, ‘Papa,’ she said, ‘If you don’t play Dumbledore, I will never speak to you again,’” Harris told Couric in an interview.

Haley Joel Osment was a favorite for Harry, but not to Columbus

Naturally, once the “Sorcerer’s Stone” adaptation was announced, fans and industry members alike began to compile their dream casts. For awhile, “The Sixth Sense” breakout Osment seemed to be a frontrunner for the titular young wizard. But Columbus wouldn’t consider him for two reasons: Osment wasn’t British, and Columbus insisted Harry be played by an unknown, soon to be recognized as Harry Potter and Harry Potter only.