Domanda sulle fanfiction

Penso sia la stessa cosa, la fan fiction può riguardare personaggi o ambientazione. Va appunto di sfumature... se è paro paro, è copyrightato... se è lontanamente ispirato, no.
Rimane il fatto che, come ha detto anche Iku, finché le vuoi postare in internet non credo sia un problema...
Riporto dalla wiki (in inglese, sulla pagina in ita c'è scritto pochissimo):

Citazione:"Fan fiction is a derivative work under United States copyright law.[21]
Some argue that fan fiction does not fall under fair use.[22] The 2009 ruling by United States District Court judge Deborah A. Batts, permanently prohibiting publication in the United States of a book by a Swedish writer whose protagonist is a 76-year-old version of Holden Caulfield of The Catcher in the Rye, may be seen as upholding this position regarding publishing fanfic, as the judge stated, "To the extent Defendants contend that 60 Years and the character of Mr. C direct parodic comment or criticism at Catcher or Holden Caulfield, as opposed to Salinger himself, the Court finds such contentions to be post-hoc rationalizations employed through vague generalizations about the alleged naivety of the original, rather than reasonably perceivable parody."[23]

Others such as the Organization for Transformative Works uphold the legality of non-profit fan fiction under the fair use doctrine, as it is a creative, transformative process.[24]

In 1981 Lucasfilms Ltd. sent out a letter to several fanzine publishers asserting Lucasfilm's copyright to all Star Wars characters and insisting that no fanzine publish pornography. Lucasfilm did not want the family- friendly aspect of the story and characters to be corrupted, despite the obvious draw that explicit content has for the fans. [25] The letter also alluded to possible legal action that could be taken against fanzines that did not comply. Later that year, the director and legal counsel of the Official Star Wars Fan Club sent fanzine publishers a set of official guidelines. Lucasfilms supported fan publications contingent on their upholding these guidelines.[citation needed]

In recent years, several prominent authors have given their blessings to fanfiction, notably J.K. Rowling. Rowling said she was "flattered" that people wanted to write their own stories based on her characters.[26] Similarly, Stephenie Meyer has put links on her website to fanfiction sites about her characters from the Twilight series.[27]

However, Anne Rice has consistently and aggressively prevented fan fiction based on any of her characters (mostly those from her famous Interview with the Vampire and its sequels in The Vampire Chronicles). She, along with Anne McCaffrey and Raymond Feist, have asked to have any fiction related to their series removed from FanFiction.Net.[26]

Most writers, however, seem to turn a 'blind eye' towards fan fiction - not actively approving it, but not discouraging it so long as it is not published for profit.[citation needed]"

Insomma, in realtà anche in internet dovresti guardare cosa ne pensa l'autore in questione... e la pubblicazione a scopo di lucro è meglio evitarla.
Salvatore non rientra tra gli autori che espressamente non vogliono ff, quindi in internet non dovresti avere problemi.
Ecco qui una lista di autori che non vogliono fan fiction, da questo articolo:

Author Author's fictional scenarios
Anne Bishop Black Jewels trilogy, others
P.N. Elrod Vampire stories
Raymond Feist The Riftwar Cycle, and some others
Diana Gabaldon Outlander series[5]
Terry Goodkind The Sword of Truth
Laurell K. Hamilton Anita Blake: Vampire Hunter, Merry Gentry
Robin Hobb The Realm of the Elderlings, Soldier Son Trilogy
Dennis L. McKiernan Mithgar series, Faery series, various
Robin McKinley various
Anne Rice gothic and religious-themed books
Nora Roberts/J.D. Robb romance novels
Archie Comics the Archie gang scenario