The old PrinceCon system was well ahead of it's time. This was back in the 80s and 90s, and was based off of early editions of D&D homebrewed into a whole new system, and then rewritten to be a dedicated ruleset. Arcane casting had two parts - a spell list, and morphic spells. Morphic spells were more expensive but very flexible. Want to turn the wood of your ship to be iron hard? Control the weather? Morphic spell. There were a number of categories of change, and guidance about size and such. The spell list had something the incorporated metamagic and upcasting. You could increase things like range, effect, damage, targets/area, and other variables.
Divine casting was a bit different, because both the available spell lists and various modifiers varied completely by your god. Much more diverse from 5e where the base spelllist is set and you can prepare from anywhere on it each day.
Both had a number of spell points based on their spellcasting ability score, and based on character level there was a chart for how much each level of spell cost, broken down to half levels. So a 5th level character casting a 2.5th level spell might be 4 SP. Always on a curve, so at higher levels you could bump up a 1st level spell fairly cheaply, but your highest level spells could be 8 SP or 13SP out of your say 15-18 per day. Oh, and this was before cantrips got introduced to D&D.
All of that said, it was a fairly crunchy system to use well. Spell points were fairly limited, and knowing your options, including morphic spells, and how much to use for cool things out of combat (XP was not combat-based even back then) vs. you were pretty weak without SP in combat, and it took some thinking to play well and quickly.
