The magic system I have for the "Playground of the Gods" (AKA Lyriaverse) storyverse has rules and limitations, like any good system of magic. But it is also flexible within those rules. Magic there is really good at making energy, moving things around. There are lots of variations on that. You can also make magical pseudo-matter that has a number of applications, anything from completely indestructible metal (adamantium), to a kind of stone that floats (luftstein). As well as bombs, portals, machines, and possibly weather work. With magic in the lyriaverse, you can make objects (including yourself) fly without even using luftstein, start fires, control the wind, and anchor objects or people in place like flies under an invisible pin.
(Pseudo-matter only looks and acts like real matter, but is made of magic and contains no atoms. If a piece of adamantium were left on a magically mostly-dead world like Earth 1, in a matter of months it will weaken and dissolve into the air around it. Only on magically powerful worlds like Orion can adamantium be left lying around; some pieces have been known to be buried in the soil for several thousand years and still be in excellent condition when dug up.)
There are limitations, of course, at least for mortals (gods are a different ball of wax).
Mortal Laws of Magic:
1. Mortal magic cannot make real matter.
2. The degree to which magic can rearrange existing real matter depends on the complexity of the rearrangement. The more complex the rearrangement, the more power and control it takes to achieve. Meaning that it is fairly simple to, say, blow up a building, and fairly simple to use magic in small, discrete steps to MAKE a building, but things like making a loaf of bread out of a pile of grass clippings using magic is, for mortal sorcerers, effectively impossible. With enough liquid magic (called godsblood), one could do it, but even then, the diagram-spell necessary to do it would take up an area of roughly one square mile, would take months to write out, and if you get the smallest thing wrong in the diagram-spell, the whole thing could explode like an atomic bomb. No mortal creature could do it without using a diagram-spell. This rule also explains rule #1.
(There are some cheats for this sort of thing. If you had enough knowledge of DNA, with time to experiment you could use magic to make a tree that grows loaves of bread. Lyria makes use of this kind of bio-magic at times.)
3. Mortal magic cannot be used to travel though time.
4. Demons from Hell and other Hell-borne lifeforms fall under the jurisdiction of The Hellmaster, and are not permitted to be freed from Hell by anyone but The Hellmaster. Any Hell creatures found outside of Hell are immediately picked up and returned by The Hellmaster. Mortals, and sometimes even gods, found to be violating this rule are subject to punishment by The Hellmaster. (There are ways of hiding Hell creatures from The Hellmaster's sights, but The Hellmaster does have others who work for him, to compensate for such workarounds. I have a couple of short stories that demonstrate the reasons why this rule is so important.) [Note: The Hellmaster is... an interesting character. It is so vast and horrifying to look upon, I think The Hellmaster's visage might make even Cthulhu shit himself.)
There are no Mortal Laws of Magic against the magical subjugation of another being, even a sentient being, nor against resurrecting the dead (the only limitation there is that if the brain has decayed, you're pretty much out of luck if you're looking for a total resurrection. An area of possible exception is powerful liches, assuming they took proper pre-death steps). Nor does any Mortal Law of Magic make it impossible for mortal sorcerers to make changes to existing life-forms (like Lyria making a giant rat/cockroach hybrid and giving it sentience), if you can work around rule #2 by taking small, discrete steps. But those magics are considered immoral and illegal by most civilizations.
Even the gods have limits, which were decided by committee long ago and written into the laws of physics there:
1. Gods cannot destroy planets or the life on them. (Nor stars, the fabric of reality, etc. etc.)
2. Gods cannot greatly alter the lifeforms on a planet without their consent.
3. Gods cannot wound or kill anyone who does not worship them. (One loophole: if the mortal in question used to worship you, but no longer does, it is still permissible, though if they've given their worship to another god, you might anger their new god.)
4. Gods cannot cause harm to a planet's life by control of the weather. (Includes blotting out the sun.)
5. Gods can travel through time, but only to the past, and they are unable to make any changes to the timeline.
6. Gods are unable to create new life forms that might threaten the ecosystem of a planet unless they are merely lifeforms made entirely of magic, as such beings generally have no need to eat. But if such beings are destructive or harmful to the environment, the Council intervenes. (This rule has not been strictly enforced ever since the civil war of the gods began.)
Of course, the gods can get around some of these limitations using mortals.