When I first started working on Just the Rules, I had thought to just make a minimalist version of Pathfinder. Don’t include all the game entities, just the rules around them, much like the D&D 3.x Rules Compendium.
While doing, so, though, I kept getting sidetracked into alternate rules sets. Instead of classes, I leaned into something more like Shadow of the Demon Lord paths. Instead of the regular spell casting rules, I was looking hard at the Spheres of Power system. This led also to Spheres of Might and Spheres of Guile, of course. I’d love to see a game built around these systems.
Regardless, I got horribly sidetracked, the first time around. Still, when I stumbled on Widening Caster Traditions, I was reminded why and how that happened. There are so many cool things I want to try!
I’m going to relegate ‘Just The Rules’ considerations to a design and packaging strategy. I still want to make a ‘Pathfinder Rules Compendium’, but I need it to stay with the rules as written. This is just about packaging and organizing.
… but the packaging guidelines will apply also to Paths Not Taken. I think it will be good to have a core book that is just core rules. Other content can be in more specialized books.
And I think I just realized a good name for a Pathfinder/Spheres-based RPG: Great-Circle RPG. A great-circle route is the shortest path between the two points on the surface of a sphere.