I-Ching Hexagram Casting
Casting puts a specific question, asked at a specific moment, into a hexagram you can read. The six lines are generated from the bottom upwards, each of them yin or yang, and together they form the primary hexagram; any line that comes out as old yin or old yang is a changing line, and flipping those lines gives the resulting hexagram. The primary hexagram speaks to how things stand now, the changing line to where the strain is greatest, the resulting hexagram to where the matter is heading.
Cast a ChartThree ways to cast
The three-coin method throws six times, reading a line off the count of heads and tails at each throw; it is the most widely used. Time-based casting takes the numbers of the year, month, day and hour to derive the upper and lower trigrams and the moving line, which suits occasions where coins cannot be thrown. Manual entry simply takes in a hexagram already obtained. The tradition gives all three equal standing — what matters is not which one you use but whether the question is clear at the moment of casting. A vague question yields an equally vague hexagram.
Primary hexagram, changing lines and resulting hexagram
The six lines of the primary hexagram describe the structure of the matter at this moment. A changing line is the line — or lines — among the six that came out as old yin or old yang; the tradition takes it to be the most active position at present, the one most worth watching. Flipping the changing lines gives the resulting hexagram, which describes what the matter will look like if it develops along these lines. Readings differ for no changing line, one changing line and several, and the question of which line takes precedence when there are several has long attracted several competing views.
The judgement, the line statements and the Image commentary
Every hexagram has a judgement (卦辭), every line has its own statement (爻辭), and the Great Image commentary (大象傳) supplies the image the hexagram is drawn from and what is inferred from it. All three layers are the text of the Zhou Yi (《周易》, the Book of Changes) and its classical commentaries, and are in the public domain. Note that the line statements mostly work by concrete analogy — “履霜，堅冰至”, treading on hoarfrost means solid ice is on its way — and what you take from one is the structural hint, not the literal thing it names.
How to ask a question clearly
The tradition sets a few plain requirements for consultation: one matter per casting, a specific question, and no repeated asking about something already settled. “Should I take this job?” yields a more readable hexagram than “How are my career prospects?”, because the first points at a definite choice. The hexagram you receive is a descriptive reflection of the present situation, there to help you think clearly rather than to take the place of judgement itself.
FAQ
Which is more accurate, coin casting or time-based casting?
Traditionally the two stand equal, and neither is generally held to be the more accurate. The coin method stresses concentration at the moment of casting; time-based casting stresses the information carried by the moment in time itself. In practice people choose according to the occasion. What really affects the quality of a reading is how specific the question is, not the method of casting.
What is a changing line, and why does it matter most?
A changing line is one of the six that came out as old yin (six) or old yang (nine). The tradition takes it to be the most active position in the hexagram — the hinge of the matter lies there. With no changing line you read the judgement of the primary hexagram; with one, you read that line's statement above all; with several, you have to decide which line leads, and on this point schools do things differently.
Can I cast repeatedly about the same matter?
The tradition advises against it. The Zhou Yi itself says “初筮告，再三瀆，瀆則不告” — the first consultation informs; asked a second and a third time it becomes importunate, and the importunate is not informed — meaning that repeated asking drains the answer of any value as a reference. The more practical reading is this: casting again usually signals that the question itself has not been thought through, and what to do at that point is to make the question clear, not to cast once more.
If the judgement says “misfortune”, does something bad have to happen?
No. The auspicious and inauspicious terms in the Zhou Yi describe where continuing a certain course tends to lead given the present structure, and they almost always come with conditions attached — under what circumstances this follows, and how it can be avoided. Treating them as settled verdicts skips past the most central thing the Zhou Yi has to say: position and timing can be adjusted.
Where can I find the full commentary on all sixty-four hexagrams?
The site has a hexagram-by-hexagram guide to all sixty-four, each with its judgement, the Great Image commentary, the original statements for all six lines with a modern plain-language translation, and separate notes on timing, career, marriage, finances and so on. For now this section exists only in Simplified Chinese.
Related terms
- Qian (乾 ☰) — The CreativeThe first of the eight trigrams; pure yang, representing heaven, creativity, and dynamic strength.
- Kun (坤 ☷) — The ReceptiveThe most yin of the eight trigrams; representing earth, receptivity, devotion, and nurturing power.
- Kan (坎 ☵) — The AbysmalOne yang in the middle between two yin lines; the trigram of water, danger, depth, and the middle son.
- Li (離 ☲) — The ClingingOne yin in the middle between two yang lines; the trigram of fire, brightness, clarity, and the middle daughter.
- Qian Wei Tian (乾為天 ䷀) — Heaven DoubledThe first hexagram of the I-Ching; six unbroken yang lines, the trigram Heaven over Heaven, symbolising pure creative force.
- Kun Wei Di (坤為地 ䷁) — Earth DoubledThe second hexagram; six broken yin lines, Earth over Earth, symbolising receptivity, devotion, and the power that carries all things.