I've been working on a pc/mobile game that deals with various party games, and I'm hesitant to start adding in any well known games like Mahjong or Shogi because I am unable to find any concrete answers on what the copyright situation is.
I've been able to find some analogous information on things like chess, where the art/rulebook/pieces are copyrighted, but the board and moves are not, so you can change what the pieces look like and face no legal issues.
I've also seen things like with Disney and the Grim Fairytales, where the Fairytales are technically public domain, the adaptations are not, so various parts of them are subject to Disney's copyright. They may not be able to win a case, but they could bankrupt you in court if they so desired.
I assume the case is similar with Mahjong because it's thousands of years old, but the pieces art could be copyrighted, so I would have to make similar but not identical art?
I know there's no cut and dry answer to this, but any food for thought would be appreciated. Thanks in advance guys!!