What Is the I Ching (Book of Changes)?
A clear, source-grounded introduction to the I Ching: what it is, where it comes from, the 64 hexagrams, changing lines, and how to read it without superstition.
What the I Ching is
The I Ching (also called the Zhouyi or Book of Changes) is one of the oldest Chinese classics, taking shape roughly three thousand years ago in the Zhou dynasty. At its core is a symbolic system of stacked yin and yang lines, together with the judgments, line statements, and centuries of commentary built around them. It began as a divinatory manual but has long been studied as a philosophical text about change, timing, and decision-making.
The 64 hexagrams
Each hexagram is six lines stacked bottom to top; each line is either yin or yang, giving 2⁶ = 64 hexagrams. Every hexagram is also an upper and lower trigram (one of the eight three-line figures). You can browse each one’s structure and source text in the 64-hexagram archive.
Changing lines and the resulting hexagram
When you cast, some lines may be “changing” (old yin or old yang); they flip to their opposite, producing a second “resulting” hexagram. The relationship between the two is often read as the direction of a situation. See what are changing lines.
How to read it without superstition
Treat the I Ching as a structured mirror rather than a prediction of fortune: it offers a set of images and situations that help you look at your own question more clearly. Hexagram Cast deliberately separates the casting process, the classical source, and modern interpretation — inspectable, and not fortune-telling.