Request authors to imagine a plotline where the use of a certain form of magic is forbidden in the fantasy world.
Dive deep into reasons why this magic has been banned. Is it too dangerous or dark? Were horrific calamities caused due to its misuse? Or, is it forbidden because it holds the power to overthrow the current ruler? Including Forbidden Magic in the plot adds an element of risk, secrecy and rebellion, and offers opportunity for rich backstory.