Why isn’t this working!?
Maybe this human is too weak.
So find more humans to test it on!
There are no scrolls in this world, but there are crystals of various sizes, colors and qualities. Every spell has a requirement on the amount and characteristics of crystals that must be held in order for the spell to be cast, crystals which would shatter should the cast be successful. Now picture a land where crystals are scarce except for high concentrations of them in specific spots throughout the land. A number of scenarios could occur, such as benign companies selling the mined valuable for cheap, a region in constant magic-intense war zone, an area of crystals in the quicksand, or an undiscovered patch next to a town...