Remathilis said:That is, of course, assuming that this Ioun is in reference to the Stones in Vance's novels...
Wikipedia said:There is controversy over the copyright status of many of Lovecraft's works, especially his later works. Lovecraft had specified that the young R. H. Barlow would serve as executor of his literary estate, but these instructions had not been incorporated into his will. Nevertheless his surviving aunt carried out his expressed wishes, and Barlow was given charge of the massive and complex literary estate upon Lovecraft's death.
Barlow deposited the bulk of the papers, including the voluminous correspondence, with the John Hay Library. However, as a young writer with no legal training, his efforts to organize and maintain Lovecraft's other writing stood little chance of success. August Derleth, an older and more established writer than Barlow, vied for control of the literary estate. One result of these conflicts was the legal confusion over who owned what copyrights.
All works published before 1923 are public domain in the U.S. However, there is some disagreement over who exactly owns or owned the copyrights and whether the copyrights for the majority of Lovecraft's works published post-1923 — including such prominent pieces as "The Call of Cthulhu" and "At the Mountains of Madness" — have now expired.
Questions center over whether copyrights for Lovecraft's works were ever renewed under the terms of the U.S. Copyright Act of 1976 for works created prior to January 1, 1978. The problem comes from the fact that before the Copyright Act of 1976 the number of years a work was copyrighted in the U.S. was based on publication rather than life of the author plus a certain number of years and that it was only good for 28 years with one renewal for an additional 28 years. The Copyright Act of 1976 retroactively extended the renewal period for all works to a period of 47 years  and the Sonny Bono Copyright Term Extension Act of 1998 added another 20 years to that, for a total of 95 years from publication. Similarly, the European Union Directive on harmonising the term of copyright protection of 1993 extended the copyrights to 70 years after the author's death. So, all works of Lovecraft published during his lifetime, are to become public domain in all 27 European Union countries on 1 January, 2008.
In those Berne Convention countries who have implemented only the minimum copyright period, copyright expires 50 years after the author's death.
Lovecraft protégés and part owners of Arkham House, August Derleth and Donald Wandrei, often claimed copyrights over Lovecraft's works. On October 9, 1947, Derleth purchased all rights to Weird Tales. However, since April 1926 at the latest, Lovecraft had reserved all second printing rights to stories published in Weird Tales. Hence, Weird Tales may only have owned the rights to at most six of Lovecraft's tales. Again, even if Derleth did obtain the copyrights to Lovecraft's tales, no evidence as yet has been found that the copyrights were renewed.
Prominent Lovecraft scholar S. T. Joshi concludes in his biography, H. P. Lovecraft: A Life, that Derleth's claims are "almost certainly fictitious" and that most of Lovecraft's works published in the amateur press are most likely now in the public domain. The copyright for Lovecraft's works would have been inherited by the only surviving heir of his 1912 will: Lovecraft's aunt, Annie Gamwell. Gamwell herself perished in 1941 and the copyrights then passed to her remaining descendants, Ethel Phillips Morrish and Edna Lewis. Morrish and Lewis then signed a document, sometimes referred to as the Morrish-Lewis gift, permitting Arkham House to republish Lovecraft's works but retaining the copyrights for themselves. Searches of the Library of Congress have failed to find any evidence that these copyrights were then renewed after the 28-year period and, hence, it is likely that these works are now in the public domain.
According to an essay by Peter Ruber, the current editor of Arkham House, called "The Un-Demonizing of August Derleth", certain letters obtained in June 1998 detail the Derleth-Wandrei acquisition of Lovecraft's estate. It is unclear whether these letters contradict Joshi's views on Lovecraft's copyrights.
Chaosium, publishers of the Call of Cthulhu role-playing game, have a trademark on several Lovecraftian phrases and creations, including "The Call of Cthulhu", for use in game products. Another RPG publisher, TSR, Inc., original publisher of Advanced Dungeons & Dragons, included in one of that game's earlier supplements, Deities & Demigods (originally published in 1980 and later renamed to "Legends & Lore"), a section on the Cthulhu Mythos; TSR, Inc. later agreed to remove this section from subsequent editions because of Chaosium's intellectual property interests in the work.
Regardless of the legal disagreements surrounding Lovecraft's works, Lovecraft himself was extremely generous with his own works and actively encouraged others to borrow ideas from his stories, particularly with regard to his Cthulhu mythos. By "wide citation" he hoped to give his works an "air of verisimilitude", and actively encouraged other writers to reference his creations, such as the Necronomicon, Cthulhu and Yog-Sothoth. After his death, many writers have contributed stories and enriched the shared mythology of the Cthulhu Mythos, as well as making numerous references to his work.