Glossary
What a Trigram Is in the I Ching
A trigram is the first figure in the I Ching that feels stable enough to name. It is small enough to read as a unit and simple enough to combine with other trigrams into larger forms.
In short
A trigram is a three-line figure built from yin and yang lines. In the I Ching, eight trigrams form the base layer from which the sixty-four hexagrams are made.
How a trigram is formed
A trigram is formed by stacking three lines from bottom to top. Each line is either yin or yang, so there are eight possible three-line combinations.
Those eight combinations are the bagua, the eight trigrams that underlie the entire system.
Why trigrams matter
Trigrams sit at the midpoint between abstract line states and full hexagrams. They are simple enough to learn directly, but rich enough to suggest pattern, movement, and emphasis.
When two trigrams are stacked, they create the six-line figure used in a cast.
How to read trigrams in practice
In a reading, the lower trigram often suggests the inner condition or base pattern, while the upper trigram suggests what is unfolding outwardly or situationally.
That is why understanding trigrams often makes a hexagram easier to interpret.