mellored
Legend
IMO: an actual grid would both be too much to keep track of in a table-top game, as well as limits some combo's. Such as wanting to be really a lighting based two weapon fighter, and needing to specialize down the wizard, picking up unwanted fire spells, and all the way down fighter side, picking up unwated armor.I'll go wild a little bit with the FF inspired mechanics: how about using the grid from FF12 to map class features and skills? All classes have a different starting point on the grid, but all classes share the same grid. All features for each class are all in the same ''sector'' on the grid. You gain XP for completing quests and use those points to progress, square by square, in you desired direction on the grid. You could go pure class and unlocking all squares for your class, go deeper and deeper in your specialized features or you can just take some features from your starting class then change direction and cross into another class grid (some kind of multi-classing).
Or just a wizard, who has 29 cantrips to choose from.
But the idea of "class/sectors" and "abilites/feats/squares" could work.