hello!! i know i could find this out with a quick read through the rules, but i want to ask here so others with the same questions can find the answers: how many players is this built for? does it require a gm? can it be played solo? thank you!
It's based on the Black Hack, which is a D&D variant, so it requires a GM and at least one player, ideally 3-4 players or so, but more or less is fine.
There is no built in support for solo play but it shouldn't be hard to play solo with an appropriate oracle / GM simulator.