No one expected much from "Pretty Woman" when they were making it. It was a modestly-budgeted romantic comedy whose stars were Richard Gere (then in the depths of a career slump) and Eric Roberts's kid sister. But when the movie was released, 25 years ago this week (on March 23, 1990), the project was transformed from overlooked stepsister to box office royalty. Mirroring her on-screen Cinderella makeover, Julia Roberts went from little-known ingenue to queen of Hollywood. Plus, the film saved Gere's career and (along with 1989's "When Harry Met Sally") revived the romantic comedy genre in Hollywood.

A quarter-century later, "Pretty Woman" remains a fan favorite, one you've seen a million times on cable. Even so, there's much you may not know about the movie -- the difficulties in casting (Gere and Roberts weren't anyone's first, second, or third choices), crises on the set, what was left out of the final film, and how the principals reunited for the successful non-sequel "Runaway Bride." Here, then, are the secrets behind "Pretty Woman," many of them divulged by director Garry Marshall in his memoirs "Wake Me When It's Funny" and "My Happy Days in Hollywood."

1. J.F. Lawton's script started out not as a peppy romantic comedy or modern-day Cinderella tale, but as a bleak drama. Edward was a ruthless corporate raider and Vivian a long-time, drug-addicted streetwalker. Part of their week-long arrangement was that Vivian had to stay off cocaine for the duration. The relationship ended with Edward striking Vivian to the ground, throwing the $3,000 at her, and leaving her screaming at him from the gutter where he first found her. The story ended with a scene reminiscent of "Midnight Cowboy," with Vivian and Kit boarding a bus to Disneyland.

2. Disney gave the script to veteran comedy director Marshall to lighten it up. On a scale from 1 to 10, where Neil Jordan's gritty prostitution drama "Mona Lisa" was a 2 and "Cinderella" or "My Fair Lady" was a 10, the studio asked Marshall to turn the script into an 8. Marshall promised a 6 or 7, but with laughs.

3. The first thing that had to go was the title, "Three Thousand." As Marshall recalled, "Test audiences given the premise and the title thought 'Three Thousand' was a movie about prostitutes from the moon who had orgasms in orbit."

4. Five writers were involved in the rewrite process, including Lawton. Softening Vivian's character was easy, Marshall recalled, but only "Big Chill" screenwriter Barbara Benedek (the lone woman among the script doctors) figured out how to soften Edward. She modeled him after Donald Trump but added vulnerability. Benedek also wrote the dental floss scene, as a funny way of revealing that Vivian did not use drugs.

5. Several actresses turned down the role of Vivian. Daryl Hannah felt the part was misogynist. Michelle Pfeiffer (whom Marshall would cast a year later as the lead in "Frankie and Johnny") also disliked the tone of the material. Marshall met with Madonna, but the singer, then 30, felt the part would be better suited to someone under 21.

6. Looking at actresses under 21, Marshall considered Molly Ringwald (then 20), but the "Pretty in Pink" star was uncomfortable with the role's sexual content. He also considered Winona Ryder (17) and Jennifer Connelly (18) but decided both were too young.

7. Producer Steve Reuther suggested 20-year-old Roberts, then known to movie audiences only as one of the three stars of cult hit "Mystic Pizza." Roberts met with Marshall and immediately told him, "I won't be naked." He was charmed.

8. The filmmakers approached Al Pacino to play Edward, but he was too busy. Marshall would soon cast him in the lead in "Frankie and Johnny." Others who read for the role included Sam Neill and Charles Grodin, but it was Gere whose readings with Roberts clicked with chemistry, and whom Marshall deemed sexy enough for the role.

9. Ralph Bellamy, then 85, was cast as James Morse, whose shipbuilding company is the target of Edward's hostile takeover bid. It was to be the final performance of his 63-year career; he died in 1991.

10. Marshall casts Hector Elizondo in every project, considering the actor his good luck charm, but Disney balked at his salary demands for playing hotel manager Bernard Thompson. Marshall paid half of Elizondo's salary out of his own pocket, though Disney reimbursed the director after the studio saw how effective Elizondo was in early footage.

11. Newbie Roberts was uncomfortable with even the limited nudity involved in reclining beneath a layer of soap bubbles in the bathtub. Marshall put her at ease with a prank. During the scene where Vivian ducks underwater and then re-emerges, Marshall had all the crew flee the set, so that when Roberts popped back up, she was alone except for the cameraman. That broke the tension.

12. Still, during the scene where Vivian and Edward are making love (not just having prostitute-client sex), Roberts was so nervous that a bulging vein on her forehead was visible, and she developed a case of hives. Calamine lotion was applied, the breakouts faded, and Roberts completed the shot.

13. No nudity was required of Gere, but one day, he stripped and walked around the set, just to shock the rest of the cast and crew.

14. During one late-night shoot, Roberts fainted on the set. It turned out that all she'd eaten in the past two days was an avocado. Marshall plied her with tuna fish, and the shoot continued.

15. To keep the budget modest (at $14 million), the filmmakers relied on product placement. For the sports car Edward borrows at the beginning of the film (and which Vivian teaches him to drive properly), the production solicited Ferrari and Porsche but were turned down because the manufacturers didn't want to be associated with a movie scene where a john picks up a hooker on the street. Lotus had no such qualms, which is why the scene features an Esprit.

16. Gere bristled at being the straight man to Roberts all the time. "You don't really need me," he complained. "You just need an image of a suit and tie. Why don't I just go home, and you can film my suit?" So the filmmakers wrote him the one-liner in the opera sequence where he covers for Vivian's "peed my pants" remark by saying, "She said she liked it better than 'Pirates of Penzance.'"

17. The scene where Edward snaps the jewelry box shut on Vivian's hand and makes her laugh was unrehearsed. Roberts was groggy from lack of sleep, and Marshall suggested the lid-slam to Gere as a way to snap his co-star back into alertness. It worked so well that Marshall kept Roberts's spontaneous response in the film. She laughed so hard that even the jeweler's security guard, on the set to keep an eye on the loaned $25,000 necklace, laughed too.

18. Roberts's laughter during the scene where she's watching "I Love Lucy" was similarly unrehearsed. Marshall made her guffaw by tickling her feet outside of camera range.

19. Gere composed the tune that Edward plays on the piano in the hotel lounge and performed it himself.

20. To ramp up the amount of fish-out-of-water comedy in the film, Marshall shot a number of scenes where Edward finds himself ill at ease in Vivian's world (namely, the Blue Banana bar). In one of those scenes, Edward is menaced by a skateboard-riding drug dealer, played by the director's son, Scott (cast because his father knew he could skateboard). But Marshall felt the scenes didn't work emotionally and cut them all.

21. The final scene, on the fire escape, had to be shot nine times. Roberts was wearing slippery shoes, and Gere's suit kept getting dirty as he climbed. Plus, there was opera music to blast and pigeons to wrangle. Still, on the final take, Marshall knew he'd gotten the ending right when one of the policemen hired to keep traffic away from the shot began to mist up.

22. The film earned $178 million in North America and another $285 million overseas, for a total of $463 million.

23. The soundtrack album was a smash, too, going triple platinum (that is, selling at least 3 million copies). It spawned such hits as Roxette's ballad "It Must Have Been Love" (which topped the Billboard chart that June), Natalie Cole's "Wild Women Do," Go West's "King of Wishful Thinking," and Red Hot Chili Peppers' "Show Me Your Soul." It also included Roy Orbison's 1964 chestnut "Oh, Pretty Woman," for which the film is named.

24. Roberts was nominated for a Best Actress Oscar. It was the only Academy Award nomination the movie received.

25. After the film's success, it seemed everyone wanted a sequel. The Buddhist Gere told Marshall that he'd been in a cave in Tibet when a monk asked him, "When are you going to make 'Pretty Woman 2'?" It was at that moment that Gere said he decided that he, Roberts, and Marshall should reunite for whatever script they could find that worked, rather than wait for a writer to craft a viable "Pretty Woman" sequel. He and Roberts found the "Runaway Bride" script and approached Marshall with it, leading to the team's successful reunion with the 1999 romantic comedy.