https://www.techdirt.com/articles/20201231/20501645979/gaming-like-1925-public-domain-game-jam-has-begun.shtml

Today's the day:works published in 1925 have run out of copyright protection and the public domain has gotten bigger, and our game jam celebrating it has begun! Gaming Like It's 1925 runs from now until the end of the month, and it's the perfect chance to start digging into of all the amazing material that's finally free for everyone to use.

The premise of the jam is simple: build a digital or analog game that incorporates, in some way or another, one or more works from 1925. You don't need to be an experienced game designer to participate — entries can be as simple as a few instructions in a PDF, or as robust as an entire board or video game, and you can make use of all sorts of easy development tools (a few of which are listed on the jam page). And there are so, so many great works to choose from, a few of which are listed on Duke University's annual round-up, which is a great place to start looking.