The I Ching (Yijing): The Book of Changes and How a Reading Is Made
The I Ching — in pinyin the Yijing (易經), the Book of Changes — is the oldest continuous text in the Chinese tradition and the root of its divination. It is a book of sixty-four figures, the hexagrams, each built from six broken and unbroken lines; and it is also a philosophy of change, in which every situation is understood as a phase passing into another phase. That double nature is why it has been read for three thousand years both as an oracle and as a work of wisdom.
This article opens the divination section of the knowledge base. It explains what the system is made of, how a reading is produced by hand, and what the result does and does not claim — the same standard of honesty applied to Feng Shui and to BaZi applies here.
What the system is made of
Everything in the I Ching is built from one distinction: a line that is yang (a solid line, ⚊) or yin (a broken line, ⚋). Three lines stacked make a trigram, and the eight trigrams — Qian, Kun, Zhen, Xun, Kan, Li, Gen, Dui — are the same eight figures that organise the eight directions of the Bagua. Six lines stacked make a hexagram: the lower trigram below, the upper trigram above. Eight trigrams multiplied by eight give sixty-four hexagrams, and between them they are held to describe every situation a person can be in.
Two arrangements of the trigrams are traditionally distinguished. The Earlier Heaven sequence, attributed to Fu Xi, is the static, symmetrical layout that describes the order of things before the world starts to move; it is the arrangement behind the Early Heaven Bagua. The Later Heaven sequence, attributed to King Wen, is the dynamic arrangement of the world as it actually runs, and it is the arrangement used by every compass school — see the Later Heaven Bagua. The received book uses the King Wen order for its sixty-four hexagrams.
A hexagram is read from the bottom up: line one is the situation as it stands at its base, line six is where it is heading. Each hexagram has a name, a judgement (a short statement of the outcome) and an image (a picture from nature offered as guidance) — and the oldest layer of the text is exactly that short and that terse. Everything else in the book is commentary.
The two classical methods
Yarrow stalks
The traditional method uses fifty yarrow stalks. One is set aside and never used; the remaining forty-nine are divided at random into two heaps, then counted off in fours, and the leftover stalks from each operation are set aside. Three such operations produce one line, and six lines — eighteen operations in total — produce a hexagram. The method is slow on purpose: the classical tradition treats the time spent handling the stalks, with a settled question in mind, as part of the reading rather than an inconvenience before it.
Three coins
The practical method uses three coins. Heads counts as 3 and tails as 2, so a throw totals 6, 7, 8 or 9:
- 6 — three tails — is old yin, a broken line that will change;
- 7 — two tails and a head — is young yang, a solid line that stays;
- 8 — one tail and two heads — is young yin, a broken line that stays;
- 9 — three heads — is old yang, a solid line that will change.
Six throws, one per line from the bottom upward, produce the hexagram. The coin method is faster and no less classical in practice; both produce the same kind of result.
How a reading is made
A reading begins with a question, and the quality of the question decides most of what follows. The I Ching is a poor instrument for "will I be happy?" and a good one for concrete situations with a real stake: whether to accept an offer, how to act in a dispute, what the actual obstacle in a project is, what a relationship is passing through. The classical instruction is to ask once, sincerely, and not to keep re-asking until an answer is flattering.
The throw gives two things. The primary hexagram describes the situation as it is, with its own judgement and image. Any lines that came up changing (6 or 9) are read individually — they mark the points of movement, the places where the situation is turning. The changing lines then invert, and the result is a transformed hexagram: the same six positions after the change. Reading a verdict means reading the primary figure, the moving lines and the transformed figure together as one movement from a present state to a coming one.
Alongside the received text stands the commentarial tradition known as the Ten Wings (十翼), the classical essays that turn a divination manual into a philosophy of change — including the Great Commentary, which discusses how change itself works. Traditionally these are attributed to Confucius and his school; historically they are the work of several hands over centuries.
One technical descendant matters for practitioners. In working divination, the form most often used for concrete questions is Wen Wang Gua (文王卦), also called Liu Yao (六爻, "six lines", with the najia 納甲 system). It uses the same sixty-four hexagrams but attaches Heavenly Stems, Earthly Branches, the Five Elements and a set of relations to each line, and reads them with the same vocabulary as BaZi. Its guides belong in this section and follow separately.
What the I Ching is not
It is not a fortune-telling machine that removes decisions. The classical reading of the text assumes the person asking remains responsible: the hexagram clarifies the structure of a situation and the direction in which it is moving, and the judgement is often advice about conduct rather than a prediction of events. It is also not interchangeable with the other arts. BaZi reads a life from birth data, feng shui reads a place from its form and directions, and the I Ching reads a question from a cast. Asking the wrong instrument is the most common beginner's mistake.
Frequently Asked Questions
How many hexagrams are there, and how are they formed?
Sixty-four. Each is built from six lines, read from the bottom up; the lower three lines form one trigram and the upper three another, so the sixty-four hexagrams are the eight trigrams paired with each other in every combination. The eight trigrams themselves are explained in The Eight Trigrams.
What do the changing lines mean?
A changing line is a line that came up as 6 or 9 — old yin or old yang — rather than as a stable 7 or 8. It marks a point in the situation that is in motion, and it is read as a specific instruction or warning alongside the hexagram's judgement. When lines change, the hexagram they produce after the change is the transformed hexagram, which describes the direction the situation is taking.
Can I use the three coins instead of the yarrow stalks?
Yes. The coin method is a classical practice in its own right and is the usual choice in modern use; the yarrow method is slower and more ceremonial, and some practitioners prefer it for that reason. What matters is that the question is settled before the cast and that the reading is done honestly afterwards.
Is the I Ching the same as Feng Shui or BaZi?
No, though they share the same symbolic alphabet of yin and yang, the five elements and the eight trigrams. Feng shui reads a space from its form and directions, BaZi reads a life from the four pillars of the birth chart, and the I Ching reads a question from the cast. The overlap in vocabulary is real; the questions they answer are different.
Where to go next
The two other classical methods that sit beside the I Ching — Qi Men Dun Jia and Da Liu Ren, and the lighter techniques such as Mei Hua Yi Shu — are covered separately in this section. If you are new to the symbolic system behind them all, start with the Eight Trigrams and the Bagua; if you want to see the same vocabulary applied to a person rather than a question, the BaZi guide is the place to begin.