What is a spell backfire?

When a crafter builds a spell strictly for themselves to gain and at the cost of another will backfire. This usually take place with neophyte students trying to show off. Though some times anger over-rides common sense and a true crafter receives the backfire of their own anger. This is true in all the sects involved in Magick, including those who follow the early books of the Hebrews and the two limbs that sprung from the Hebrew books.