The book includes a series appendices, which describe the unique dialogue and slang used on the show, lay out the differences between the Classic and Cinematic Unisystem rules, provide charts and summaries of the more important concepts, and finally offer a full glossary and index.

In 2005, Eden Studios released the Revised Core Rulebook (ISBN 1-933105-10-0) which incorporates existing errata into the book, updates some rules to bring the Buffy RPG more in line with the Angel Roleplaying Game, and expands upon the material provided in the original Core Rulebook, providing updated characters and adversaries for the sixth and seventh seasons of the series.

(ISBN 1-891153-90-0) The BtVS equivalent of a Monster Manual, this supplement explores vampires, demons, and other adversaries in greater depth, providing an expanded and updated collection of villains and elaborating upon a number of supernatural abilities.

Like the previous books in this line, Monster Smackdown includes a Djinn Season episode, "The Once and Future HST," which plays with events from the series as well as mythological elements.

(ISBN 1-891153-94-3) As implied by the title, this supplement offers an expanded ruleset for magic spells and spellcasters; however, it also provides a number of new mystical and psychic abilities, new Qualities and Drawbacks, and expands the magical milieu of the game to include Enchanters (who create blessed swords, lightning-throwing gauntlets and other such items) and Superscientists (such as Warren Mears).

According to author Phil Masters, he had just submitted a solicited manuscript, a guide to the Watchers called Tea and Crossbows, a few days before the Eden Studios announced the loss of their license.

[citation needed] The Buffy RPG has already contributed to Buffyverse canon, in that Faith Lehane and Kendra Young's last names were provided by Joss Whedon in response to queries from Eden Studios.