Quickleaf
Legend
There were some great ArsMagica d20 rules on some website. ArsMagica uses a skill-based system, and would be an excellent resource in designing your own skill-based magic system. I really like the idea of a spell check being identical to a skill check, and the spell's effect being determined by what DC is reached with the roll. I.e. the fireball spells at DC 12 might inflict 3d6, but at DC 16 is 4d6, and at DC 20 is 5d6, and so on. You could use the 3e Scry skill. In fact, the Blue Rose RPG (Green Ronin) seems to do something similar, though it's too early to say as it hasn't been released yet.
