(Rewriting this from scratch since nobody answered anyway.)
So, whatever I tried didn't quite work. My big idea was that you'd have three main stats: Power, Grace and Focus. Power means how much damage you can dish and take. Grace means how well you move, in particular how hard you are to hit. Focus means how easily you notice things, how fast you learn, spellcasting ability and the like. You'd start with two points in each, and get three more points to distribute as you like. Each point represents a d6, so an average score of 3 in a stat means you roll 3d6 for it. Other stats like maximum health would be implicit.
Question is, how to use all that. I considered giving each opponent a combat score as described above, and rolling against that. I considered opposed rolls, in various combinations. Nothing quite worked. The problem here is likely that I keep trying to treat this like a simplified version of my other rule system, and it's the entirely wrong direction.
But what else to do? No idea yet. Oh well, thanks for reading my ramblings, and see you around.