Can a jam be for related supplements, rather than whole separate games? For example, one page settings or adventures or similar things.
An adventure jam would be cool! I could also see doing supplement jams for different systems, like doing a D&D supplement jam or a Dungeon World supplement jam or a Blades supplement jam
I believe there is a fairly famous "One Page Dungeon" contest. But this also sounds like a wonderful Jam premise.
Yeah, thinking more collaborative or themed than competitive!