For all its complexity, divination by means of the Eight Cyclical Characters is based on the principle that a person's Five Elements readings should be just right, not tending towards extremes.
當然，八字批命不只如此，另外像「五行寄生十二宮」、「刑衝害化合」、以及各種星宿、神煞等等，也都是學算命者必備的常識。