What Are the Primary, Resulting and Nuclear Hexagrams?

The primary hexagram

Take the six lines from your six throws and, whether they change or not, draw yang as yang and yin as yin. The hexagram they form is the primary hexagram (本卦, ben gua), also called the hexagram met (遇卦, yu gua) or the zhen hexagram (贞卦, zhen gua). It speaks of the situation you are in right now, and it is the foundation of the reading.

The resulting hexagram

Turn the old yang lines of the primary hexagram into yin and the old yin lines into yang, and leave the rest alone. The hexagram you get is the resulting hexagram (之卦, zhi gua), also called the changed hexagram (变卦, bian gua) or the hui hexagram (悔卦, hui gua). The word zhi (之) means "to go to": when the Zuozhuan ("Zuo Commentary") says "met Guan going to Pi" (遇观之否), it means the diviner obtained Guan (Contemplation), moving toward Pi (Standstill).

The resulting hexagram speaks of where things are heading. If there are no changing lines, there is no resulting hexagram, which means the situation is stable and no major turn is likely in the short term.

The nuclear hexagram

Take the second, third and fourth lines of the primary hexagram as a lower trigram, and the third, fourth and fifth lines as an upper trigram, and put them together as a new hexagram. This is the nuclear hexagram (互卦, hu gua). It is hidden in the middle of the primary hexagram, and has traditionally been used to look at the inside of a matter, the things that stay out of sight while it unfolds.

Take Kun (Exhaustion), with Kan (Water) below and Dui (Lake) above. Lines two, three and four form Li (Fire); lines three, four and five form Xun (Wind). So the nuclear hexagram has Xun above and Li below: Jiaren (The Family). The nuclear hexagram is for reference only; it does not decide the reading.

The opposite and the reversed hexagram

• The opposite hexagram (错卦, cuo gua): all six lines are switched, yin for yang and yang for yin. The opposite of Qian (Heaven) is Kun (Earth). It shows the opposite side of the matter.
• The reversed hexagram (综卦, zong gua): the whole hexagram is turned upside down. Zhun (Difficult Beginnings) turned over is Meng (Youthful Ignorance). Most of the sequence of the sixty-four hexagrams is made up of such reversed pairs. It shows how things would look from a different standpoint.

For which text to read first after casting, see How to read changing lines.