I've been noticing a fair number of Cthulhu themed rpgs being published recently (i.e. Trail Of Cthulhu). Out of curiosity, has Lovecraft's work become 'public domain'?
Especially everything Derleth.Note as well not all Mythos works are safe as there are other autors who wrote Mythos stuff from 1923 on that are definitely still under copyright.
the only Trademark is on the name Calll of Cthuhlu in relation to games (You could republish the story of the same name, or call a vacum cleaner that, or set up restaurant chain called that).
either copyright has expired or it never existed in the first place due to lack of registration. It's the same for most of REH's Conan stories.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.