The method of turtle shell divination is a manner of divination with a long history.
Traditional turtle shell diviners would place a polished, hole-punched beast bone or turtle shell under a spiritual flame, observing the signs burned into it by the flame in order to predict fortune and misfortune, and to discern right from wrong.
In modern times, with the rise of various wizarding theories and schools, this ancient method of divination gradually abandoned many traditional molds. For example, the turtle shell needed to be from a virgin turtle of even age found at the foot of a southern mountain, the beast bone had to be the scapular bone of an eight-foot ox born in spring. Furthermore, auspicious dates and times needed to be selected for punching holes in the oracle bones, which could only commence after bathing, fasting and offering sacrifices.