Stem-Branch Assignment (Najia)
Last updated 5/21/2026
Cast Qian over Heaven today. Cast it again next month. Have someone else cast it on another day.
The date changes. The month branch changes. The day branch changes. The void window changes.
The six line labels do not change.
For Qian over Heaven, the branches on lines 1-6 are always:
Zi, Yin, Chen, Wu, Shen, Xu.
That is the point of najia: every hexagram line receives a fixed stem-and-branch identity before the calendar does anything to it. The calendar decides strength, timing, void, clash, combination, and release. Najia tells us what line-objects are actually sitting in the chart.
Think of it this way:
- Najia is the cast’s inventory. It tells each line which stem and branch it carries.
- The date is the weather. It tells us which of those line-objects are strong, weak, active, blocked, or temporarily unavailable.
Those two layers are separate. If you blur them together, the rest of the method becomes impossible to learn cleanly.
What Najia Means
Najia literally means something like “installing the stems into the hexagram.” In working English, this course calls it calendar-line assignment or stem-branch assignment.
The practical job is simple:
- Split the hexagram into a lower trigram and an upper trigram.
- Look up the lower trigram’s inner assignment.
- Look up the upper trigram’s outer assignment.
- Put those six stem-branch labels on lines 1-6.
Technical source labels and pinyin live in the Wen Wang Gua Terminology page. You do not need character forms to use the table.
Source: the assignment table follows the Najia Installation Song in Bushi Zhengzong, volume 7, cross-checked against the bottom-up installation rule in Bushi Quanshu, volume 2.
Inner And Outer
Every hexagram is two stacked trigrams:
- Inner trigram: the lower three lines, lines 1-3.
- Outer trigram: the upper three lines, lines 4-6.
The same trigram gets a different assignment depending on position. Heaven below is not the same lookup as Heaven above. Wind below is not the same lookup as Wind above.
That is the trap in this module. The trigram shape may look the same, but its table position changes the labels.
The Working Table
Use this table directly. It is the learner interface.
| Trigram | Pattern | Family role | Inner stem | Inner branches, lines 1-3 | Outer stem | Outer branches, lines 4-6 |
|---|---|---|---|---|---|---|
| Heaven / Qian | 111 | Father, yang | Jia | Zi, Yin, Chen | Ren | Wu, Shen, Xu |
| Thunder / Zhen | 001 | Eldest son, yang | Geng | Zi, Yin, Chen | Geng | Wu, Shen, Xu |
| Water / Kan | 010 | Middle son, yang | Wu | Yin, Chen, Wu | Wu | Shen, Xu, Zi |
| Mountain / Gen | 100 | Youngest son, yang | Bing | Chen, Wu, Shen | Bing | Xu, Zi, Yin |
| Wind / Xun | 110 | Eldest daughter, yin | Xin | Chou, Hai, You | Xin | Wei, Si, Mao |
| Fire / Li | 101 | Middle daughter, yin | Ji | Mao, Chou, Hai | Ji | You, Wei, Si |
| Lake / Dui | 011 | Youngest daughter, yin | Ding | Si, Mao, Chou | Ding | Hai, You, Wei |
| Earth / Kun | 000 | Mother, yin | Yi | Wei, Si, Mao | Gui | Chou, Hai, You |
Source: Bushi Zhengzong, volume 7, Najia Installation Song and installation table. The course table is the same assignment unpacked into English labels.
How To Read The Table
For any hexagram:
- Identify the lower trigram.
- Read its inner stem and inner branches onto lines 1, 2, and 3.
- Identify the upper trigram.
- Read its outer stem and outer branches onto lines 4, 5, and 6.
Do not infer the upper half by memory unless you know the table cold. Look up both halves.
Why The Table Has This Shape
You do not need the derivation to use najia, but the pattern is useful:
- The four yang trigrams use the yang branch track: Zi, Yin, Chen, Wu, Shen, Xu.
- The four yin trigrams use the yin branch track in reverse working order: Chou, Hai, You, Wei, Si, Mao.
- Heaven and Earth each use two stems, one for the inner position and one for the outer position.
- The other six trigrams use the same stem inside and outside.
- Water and Mountain wrap around the branch cycle, which is why Water above ends with Zi and Mountain above includes Zi in the middle.
This is enough theory for the learner stage. The table is still the working tool.
Case 1: Qian Over Heaven
Case 1 uses Qian over Heaven, Hexagram 1, also called Heaven over Heaven.
Both halves are Heaven:
- Inner trigram: Heaven.
- Outer trigram: Heaven.
From the table:
| Line | Trigram position | Stem | Branch |
|---|---|---|---|
| 1 | Inner Heaven | Jia | Zi |
| 2 | Inner Heaven | Jia | Yin |
| 3 | Inner Heaven | Jia | Chen |
| 4 | Outer Heaven | Ren | Wu |
| 5 | Outer Heaven | Ren | Shen |
| 6 | Outer Heaven | Ren | Xu |
Read the branches from bottom to top:
Zi, Yin, Chen, Wu, Shen, Xu.
That matches the source case. The line roles and elements are not coming from nowhere; they sit on top of these branch labels.
Source: Yehe Laoren, Zengshan Buyi, Case 1. The source case records this Qian over Heaven branch sequence.
Case 1 Changed Chart: Wind Over Heaven
Case 1 changes into Wind over Heaven, Hexagram 9.
Only the upper trigram changes. The lower trigram is still Heaven.
From the table:
| Line | Trigram position | Stem | Branch |
|---|---|---|---|
| 1 | Inner Heaven | Jia | Zi |
| 2 | Inner Heaven | Jia | Yin |
| 3 | Inner Heaven | Jia | Chen |
| 4 | Outer Wind | Xin | Wei |
| 5 | Outer Wind | Xin | Si |
| 6 | Outer Wind | Xin | Mao |
Now the branches are:
Zi, Yin, Chen, Wei, Si, Mao.
Notice the clean split. Lines 1-3 keep the same labels because the lower trigram stayed Heaven. Lines 4-6 change because the upper trigram became Wind.
That is exactly how najia should feel: not mystical, not interpretive, just a deterministic table lookup.
Second Example: Water Over Thunder
Now try a mixed hexagram: Water over Thunder, Hexagram 3.
The lower trigram is Thunder. The upper trigram is Water.
| Line | Trigram position | Stem | Branch |
|---|---|---|---|
| 1 | Inner Thunder | Geng | Zi |
| 2 | Inner Thunder | Geng | Yin |
| 3 | Inner Thunder | Geng | Chen |
| 4 | Outer Water | Wu | Shen |
| 5 | Outer Water | Wu | Xu |
| 6 | Outer Water | Wu | Zi |
Bottom to top:
Zi, Yin, Chen, Shen, Xu, Zi.
The repeated Zi is not a mistake. Water’s outer assignment wraps around the yang branch track. Repetition is allowed.
What Najia Gives Us
After this step, each line has a stem and branch. That gives us three immediate hooks:
- Element: each branch has a fixed Five Phase element.
- Line role: the branch element can be compared to the palace element, producing Parent, Officer, Sibling, Wealth, or Child.
- Calendar contact: the month branch and day branch can now interact with each line’s branch.
Najia does not decide whether a line is strong. It does not decide whether a line moves. It does not decide whether the chart is auspicious. It gives the chart its fixed line identities so the later layers have something to judge.
The Main Trap
The main error is using an inner assignment in an outer position.
Example: Wind below uses Chou, Hai, You. Wind above uses Wei, Si, Mao.
If Wind is the upper trigram and you put Chou, Hai, You on lines 4-6, every later calculation is wrong. The line elements will be wrong. The line roles will be wrong. The date interactions will be wrong.
The cure is boring and effective:
Look up the inner half and the outer half separately.
Do that until the table is automatic.
Where This Lands Us
We can now give every line in any hexagram a fixed stem-branch label.
Next, we compare each line’s branch element to the palace element. That produces the five line roles: Parent, Officer, Sibling, Wealth, and Child.
→ 2.4 The Relative Types.