| Anything before 1923 IS public domain, there are no exceptions. His work from 1923 on could possibly be under copyright but most are not since most were not renewed. Trademark never expires but 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). If you want to use something from before 1923 you are 100% safe. If you want to use something from 1923 on you are probably safe, but to be 100% safe a check would have to be made on each seperate work. This is why you are now seeing more and more Lovecraft based games and items. 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.
__________________ Brain: Come Pinky! We must prepare for tomorrow night.
Pinky: Why? What are we going to do tomorrow night?
Brain: The same thing we do every night....TRY TO TAKE OVER THE WORLD! | 
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