The concept was first visited through Whedon's script for the 1992 movie, Buffy the Vampire Slayer, which featured Kristy Swanson in the title role. The director saw it as a "pop culture comedy about what people think about vampires." Whedon disagreed: "I had written this scary film about an empowered woman, and they turned it into a broad comedy. It was crushing." The script was praised within the industry, but the movie was not.

Several years later, Gail Berman, a Sandollar Productions executive, approached Joss Whedon to develop his Buffy concept into a television series. Whedon explained that "They said, ‘Do you want to do a show?’ And I thought, ‘High school as a horror movie.’ And so the metaphor became the central concept behind Buffy, and that’s how I sold it." The supernatural elements in the series stood as metaphors for personal anxieties associated with adolescence and young adulthood. Whedon went on to write and partly fund a 25-minute unaired Buffy pilot[16] that was shown to networks and eventually sold to the WB Network. The latter promoted the premiere with a series of History of the Slayer clips, and the first episode aired on March 10, 1997.

Executive producers :

Joss Whedon was credited as executive producer throughout the run of the series, and for the first five seasons (1997-2001) he was also the show runner (a role that involves serving as head writer and being responsible for every aspect of production). Marti Noxon took on the role for seasons six and seven (2001-2003), but Whedon continued to be involved with writing and directing Buffy alongside projects such as Angel, Fray and Firefly. Fran Rubel Kuzui and her husband, Kaz Kuzui were credited as executive producers but were not heavily involved in the show. Their credit, rights and royalties over the franchise relate to their funding, producing and directing of the original movie version of Buffy.

Writing :

Script-writing was done by Mutant Enemy, a production company created by Whedon in 1997. The writers with the most writing credits include: Steven S. DeKnight, Jane Espenson, David Fury, Drew Goddard, Drew Greenberg, Rebecca Rand Kirshner, Marti Noxon and Doug Petrie.

Jane Espenson has explained how scripts came together. First, the writers talked about the emotional issues facing Buffy Summers and how she would confront them through her battle against evil supernatural forces. Then the episode's story was "broken" into acts and scenes. Act breaks were designed as key moments to intrigue viewers so that they would stay with the episode through advertisements. The writers collectively filled in scenes surrounding these act breaks for a more fleshed-out story. A whiteboard marked their progress by mapping brief descriptions of each scene. Once "breaking" was done, the credited author wrote an outline for the episode, which was checked by Whedon or Noxon. The writer then wrote a full script, which went through a series of drafts, and finally a quick rewrite from the show runner. The final article was used as the shooting script.

Casting :

The title role went to Sarah Michelle Gellar, who had appeared as Sydney Rutledge in Swan's Crossing and Kendall Hart in All My Children. At age eighteen in 1995, Gellar had already won a Daytime Emmy Award for Outstanding Younger Leading Actress in a Drama Series. In 1996 she was initially cast as Cordelia Chase during a week of auditioning.

Anthony Stewart Head had already led a prolific acting and singing career but remained best known for a series of twelve coffee commercials with Sharon Maughan for Nescafé Gold Blend. He accepted the role of Rupert Giles.
Unlike other Buffy regulars, Nicholas Brendon had little acting experience, instead working various jobs — including production assistant, plumber's assistant, veterinary janitor, food delivery, script delivery, day care counselor and waiter — before deciding to break into acting to help him overcome a stutter. He landed his Xander Harris role following only four days of auditioning.

Alyson Hannigan was the last of the original four to be cast. Following her role in My Stepmother Is an Alien, she appeared in commercials and supporting roles on television shows throughout the early 1990s. In 1996 the role of Willow Rosenberg was initially given to Riff Regan for the unaired Buffy pilot but Hannigan auditioned when the role was recast for the series proper. She described her approach to auditions in an interview through her treatment of a particular moment: Willow tells Buffy that her Barbie doll was taken from her as a child, and Buffy asks if she ever got the Barbie back. "Willow's line was 'Most of it.' And so I thought I'm gonna make that a really happy thing. I was so proud that she got most of it back. That clued in on how I was going to play the rest of the scene. It defines the character." Her approach subsequently helped her win the role.