Okay, can someone give me a definition of High Fantasy and Low Fantasy?
In Low fantasy, you could make a spell that makes a city sick with a ton of effort, but fireballs wouldnt be too tough.
In High Fantasy, you kill the deity of magic and your entire world and planar structure collapses in outself as the unregulated energies spill out of control, warping the fundamental nature of all things that were nominally considerd as the universe. This will take several hundred years, including many events similiar to the Dragon Break in the process.
Harry Potter is Low Fantasy: They can hardly use magic without wands. Epic D&D is high fantasy: You can deal 300d6 damage to a massive area, at the cost of 200d6 damage to yourself.
In Low Fantasy, you MIGHT be able to stop the cultists from doing the bad stuff to make the really bad stuff. But in High Fantasy, you would have at least a sliver of hope of being able to find the upper-hand.
If your characters can hardly change the fact that their terrain is primarily immobile, youre in low fantasy. If the ground is solid only because it happens to be in that state at this moment, you're heading toward High, Corrosive Fantasy.
In low fantasy, you could blow up a person's head like tha tscene in scanners. In high fantasy, you can use psychic powers to blow up stars.
Dune is high fantasy: Sufficiently advanced that it may as well be magic. Do not watch the movie or this statement will confuse you.