I’m curious about this answer, too. Looking up Heyer, for example, Project Gutenberg considers one of her works from 1921 to be in the public domain in the USA (https://www.gutenberg.org/ebooks/38703). Wikipedia considers only laws local to California/USA to be relevant (https://en.wikipedia.org/wiki/Wikipedia:Public_domain#:~:text=In%20the%20US%2C%20any%20work,by%20that%201928%20date%2C%20though.), and itch.io seems to do the same (https://itch.io/docs/legal/terms#14-governing-lawjurisdiction). Since they are the hosting sites for the content, does that mean the creator’s and players’ countries are irrelevant?