The I Ching 3-Coin Method: How to Cast a Hexagram with Three Coins, Step by Step
What you need
Three identical cash coins (or ordinary coins), a sheet of paper and a pen. Settle on one thing to ask, and make it specific: not "How is my luck?" but "Is now the right time to move to this job?"
The ancient method of the Zhouyi (the core text of the I Ching) uses fifty yarrow stalks (see how the yarrow-stalk method differs from the coin method); the coin method is a later simplification. Already in the Tang dynasty, Jia Gongyan wrote in his Yili Shu ("Subcommentary on the Ceremonial Rites"): "The ancients drew the lines on the ground with a stick; now coins are used." In the Southern Song, Xiang Anshi recorded that the diviners of his day "throw three coins", and said that this method is the one handed down as the Huozhulin ("Fire Pearl Forest"), whose source can be traced back to the Han-dynasty school of Jing Fang.
The steps
- Fix the rule: a back counts 3 and is yang; an inscribed side (the side with the characters) counts 2 and is yin. Set the rule before you throw, and do not change it partway.
- Shake the three coins in your cupped hands and throw them. Add up the three values. The sum can only be one of four numbers: 6, 7, 8 or 9.
- Draw one line according to the table below. The first throw gives the bottom line.
- Throw six times in this way, drawing the first, second, third, fourth, fifth and top lines from the bottom up. The six lines make a hexagram. This is the primary hexagram.
- Turn every old yang into yin and every old yin into yang, leave the rest as they are, and you have the resulting hexagram. If there is no old yang or old yin, there is only the primary hexagram.
| Three coins | Sum | Line | How to draw it | Changes? | Probability |
|---|---|---|---|---|---|
| Three backs | 9 | Old yang | ━━━ with ○ beside it | Changes to yin | 1/8 |
| Two backs, one inscribed side | 8 | Young yin | ━ ━ | Does not change | 3/8 |
| One back, two inscribed sides | 7 | Young yang | ━━━ | Does not change | 3/8 |
| Three inscribed sides | 6 | Old yin | ━ ━ with × beside it | Changes to yang | 1/8 |
Why do two backs and one inscribed side make a yin line? Because 3 plus 3 plus 2 is 8, and even numbers are yin. What counts is whether the sum is odd or even, not which side shows more often.
After the throws
Once you have the primary hexagram and the resulting hexagram, you still need to know which text to read. That depends on the number of changing lines: see How to read changing lines: Zhu Xi's seven rules. For why the lines are called "nine" and "six", see Old yin, old yang, young yin, young yang.
Casting on this site (the red seal 起卦, "Begin") follows exactly these steps: each throw uses three coins, each coin's face is decided by a cryptographically secure random number, and the probabilities of the four kinds of line match the table above.
Common questions
- Is the inscribed side yang, or the back? Both conventions are in circulation. This site counts a back as 3 and an inscribed side as 2, which agrees with what Xiang Anshi of the Southern Song recorded in his Xiangshi Jiashuo ("Family Teachings of Master Xiang"): "two backs and one inscribed side make chai (拆, the broken line)", which is young yin; "two inscribed sides and one back make dan (单, the single line)", which is young yang; "all inscribed sides make jiao (交, the crossed line)", which is old yin; "all backs make chong (重, the doubled line)", which is old yang. What matters is to decide beforehand.
- Do I have to use antique coins? No. Any three identical coins with two clearly different sides will do. Chinese folk practice favors Qianlong Tongbao coins; for the reason, see Why Qianlong Tongbao coins are used for I Ching divination.
- Can I throw several times and keep the best result? No. See One question, one cast.