How changing lines work
Changing lines are where an I Ching reading becomes specific. They show which parts of the situation are in motion, and they produce a second hexagram showing where that motion leads.
Four kinds of line
Every cast line has one of four values. The number comes from the coin or yarrow count:
| Value | Name | Drawn as | Changes? |
|---|---|---|---|
| 6 | Old yin | broken line, marked × | Yes, becomes solid |
| 7 | Young yang | solid line | No |
| 8 | Young yin | broken line | No |
| 9 | Old yang | solid line, marked ○ | Yes, becomes broken |
The idea comes from the cycle of yin and yang: anything that reaches its extreme turns into its opposite. "Old" lines have reached that point, while "young" lines are still growing and stay as they are.
From primary to resulting hexagram
The six lines as cast form the primary hexagram. Flip every changing line and keep the others, and you get the resulting hexagram. In the example below, lines 2 and 5 are changing:
Line 2 (solid, old yang) becomes broken, and line 5 (broken, old yin) becomes solid. Hexagram 46 becomes hexagram 39.
In a reading, you read the text of each changing line in the primary hexagram. The resulting hexagram is usually read as a whole (its name, judgment and image) and not line by line.
When several lines change
Commentators have long disagreed about how to weigh several changing lines. Many modern readers simply read all of them, often treating the uppermost as the culmination. The best known traditional system comes from Zhu Xi (1130–1200):
- No changing lines: read the judgment of the primary hexagram.
- One: read that line.
- Two: read both, giving more weight to the upper line.
- Three: read the judgments of both hexagrams, the primary as the base.
- Four: read the two unchanging lines of the resulting hexagram, giving more weight to the lower.
- Five: read the one unchanging line of the resulting hexagram.
- Six: read the judgment of the resulting hexagram. Hexagrams 1 and 2 are the exception: each has a special statement for when all six lines change.
This site always shows every changing line and also notes which lines Zhu Xi's convention would emphasize. You can decide how much weight to give it.
Why coins and yarrow give different results
With three coins, old yin and old yang are equally likely (1 in 8 each). With the yarrow-stalk method, old yang is three times as likely as old yin (3 in 16 against 1 in 16). Some practitioners prefer the yarrow odds for that reason. Both are available when you cast a reading.