Lanefan
Victoria Rules
OK, I could get behind something like this. But you'll get howls of protest from those who want to use Polymorph as a combat spell.I don't think anyone's contesting a powerful ability should have limits. It's the type of limits that's in question.
You could have different limitations that are more based in myth.
Let's use polymorph as an example. We can use Medea as the mythological spellcaster of this effect in our example.
So you might have a spell that when you cast it, you enchant a piece of food such that when it is consumed, the consumer must make a save or be transformed into a pig (or similar animal).
This places new limitations on the spell. It's still powerful, but not in the fire-and-forget way of the existing version. The caster needs to figure out ways to deliver the food to the intended target. This might be as simple as tossing an apple into the gullet of an on rushing land shark, or as difficult as convincing a suspicious guardsman to accept your "gift".
That said, in 1e there used to be two different polymorph spells: Polymorph Self and Polymorph Other. Poly Other was baneful and carried massive risks to the target - you would never even think of casting it on an ally. Poly Self was safe but had serious limits on what you could turn yourself into, and only worked on the caster. These were decent limits.
Somewhere along the editions these two spells got combined, and all the risks were taken out; which broke it.