Worldbuilding bromide entry #8: The skill of magic must not only have physical limitations, but mental or emotional limitations as well.

There are far, far too many systems of magic out there where the only limiting factors on magic are whether the spellcaster has the magic required or the skill level required to cast the spell. The idea that this type of magic can exist without causing the near collapse of the economy, the near collapse of society, or both seems unrealistic to me. <br><br>A magic system that also has mental or emotional limitations is more logical, in my opinion. For example, a spellcaster may not be able to cast magic while mentally or emotionally upset, or the fact that magic attracts the attention of malevolent magic users or beings.<br><br>An example of a magic system where spellcasters have not only physical limitations, but also mental or emotional limitations is in the Kingkiller Chronicle by Patrick Rothfuss. In this series, magic, known as nomenclature, can only be used by someone who knows the true name of the object being affected by the magic, who must also be able to visualize the object being affected. If the spellcaster can not visualize the object in the way and the state in which the spellcaster wants to be after the spell is cast, the magic will not work.