"Random" Magic systems include everything here.
I AM STILL THE WINNER.
Gimmie a hiface.
Edit: Now that my "spring is here and it's nice outside, let's be a nuisance, " mood is out of the way.
Brandon Sanderson had an interesting "magic" system in his Mistborn series. Consuming x reagent produces y effect. There are 6 (8, 10) reagents. One small (read: minuscule) group can use all reagents. Another larger (read: tiny) group can use 1, ( individual 1 can use x, individual 2 can use c.) All the "powers" are based in pairs. The pairs formed a section, like Physical internal/external, mental internal/external time(x2) internal/external (those specific powers let you see yourself as you could have been/were in two timelines, or somone else) aaaand another one I forget. For example, Iron and Steel. Ingesting Iron lets you Pull on metal, exerting your body weight on it. Smaller-than-you metal is effected as if you were using your entire body weight to move it (Thus coins and such shoot towards you at ridiculous speeds.) Heavier-than-you metals pull you towards them. Steel is the opposite, Pushing (interesting fact, those with Steel could "fly" by pushing off coins on the ground and the like. Basically making huge jumps because while the metal is smaller, the earth is not.)
In a procedurally generated df, number of reagents, reagents, and effects would be "randomly" generated.
Edit2: Also of note, the reagents "Burned" at differing speeds. Speeds of Burn could be generated.
OORRR.
I once played a game where words of power, which were described in the game manual, decided magnitude (trivial to godlike), target (Yourself, items, monster, world, area ect), effect(fire, water, wind, earth, death, life, ect), and so on.. I think there was like 8 levels each with 8 words. You had a (effectively) invisible 'level' in magic, effecting what spells you can cast based on those magnitudes, effects, and target things. How many spells you could cast, and of what power, was also based on your mana, which grew with your level. If you tried to cast too powerful a spell, your mana was drained, spell fizzles or backfires or some such, and you have to wait for three years irl to get your mana back. Unfortunately, having pirated the game, I did not have the game manual.
And thus the age of "Trial and Error" was born. The only game to rival the fun I had blowing myself up is DF.
In df, words of power, their number, magnitudes and their number, ect would be generated.
Course, these are frameworks that could be thrown in with the 100000 other frameworks and rules already suggested.