Joss Whedon had originally planned for viewers to never see Buffy's parents. However, he realized this could get complicated and therefore wrote in Buffy's mother Joyce, who would become an important character for the rest of the series.
The Master's look originally featured a beard and long hair before Mark Metcalf suggested the bald look as a homage to Count Orlok (Max Schreck) in Nosferatu (1922).
Up until the third season, the school set had only one hallway and the Bronze was actually just an old warehouse.
The high school used for external and some internal scenes in the series is Torrance High, the same school used for Beverly Hills, 90210 (1990).