Six Lines basics

Hidden line (Fu Shen)

By Vi Nhật Sơn · Updated 2026-09-18

Phục thần

Hidden line (Fu Shen) — what is it? Hidden line: when a hexagram has no Target line we go by the Pure hexagram at the head of the palace; the line standing for the Target line is the Hidden line.

When a hexagram has no Target line, we go by the first hexagram of that palace, which is a Pure hexagram. The Target line is then written in at the same position as in the primary hexagram. The line standing for the Target line is called the Hidden line, and the line at the same position as the Hidden line in the primary hexagram is called the Flying line.

Why we have to find a Hidden line

In theory every hexagram has a result, whether it is a hexagram with no moving line or one with all six lines moving. The result depends on the Target line, but not every hexagram has a Target line. So in the case of a hexagram with no Target line, we are obliged to find a Target line for it, because without a Target line there is no frame of reference at all for working out the result of the event. A Pure hexagram always has the full set of Six Relations, so when we refer to it, the Target line we need is certain to be there.

How the Hidden line is written in

Example:

**Coming to Meet (Gou)** Heaven (Qian) Palace · Metal
Parents	Xu Earth
Siblings	Shen Metal
Officer line	Wu Fire	Resp.
Siblings	You Metal
Offspring	Hai Water
Parents	Chou Earth	Self

In the hexagram Coming to Meet (Gou) there is no Wealth line; the Wealth line in Coming to Meet (which is the second hexagram of the Qian palace) belongs to Wood, so if the Day or the Month is not Wood, we take it from the Qian hexagram. Then, in the Qian hexagram, line 2 is the Wealth line at Yin Wood, and that is read as the Hidden line; we write under line 2, the Offspring line at Hai Water, the Wealth line at Yin Wood.

The Wealth line at Yin Wood is then called the Hidden line, and the Offspring line at Hai Water is called the Flying line.

Taking the Day or the Month as the Target line

If the Day or the Month is of the same element as the Hidden line, we take that very Day or Month as the Target line. For example: on a Mao day, with the hexagram Coming to Meet above — if the Target line is Wealth, there is no Wealth line in Coming to Meet, and the Wealth line in this hexagram would lie at the element Wood, which coincides with the element of the branch of the Day, so we write under the Chou Earth line the Wealth line at Mao Wood, keeping the element and the branch of the Day.

This Wealth line is then acted on by the remaining one of the Day and the Month, and by the moving lines, like an ordinary line, that is, it can be Void, be clashed by the Month, be combined….. But in this case the Target line does not have a Six Spirit of its own as it usually would. This is extremely important, because we are not to put this Target line at the hidden position and take the Six Spirit of that line's position for reading the information.

Note that if the Target line does not appear in the hexagram but coincides in element with the Day or the Month, then the first priority must be to take the Day or the Month; only if that does not work do we go to the Flying line and the Hidden line.

The cases of Flying and Hidden

If the Target line does not coincide with the Day or the Month, the following cases arise:

The Hidden line is Void: certainly spoilt, except where the Hidden line is Prosperous and the Flying line is clashed, or is in Break, the Tomb or Extinction; then, although the Hidden line is Void, it is not held down and comes up, and it is read as an ordinary hexagram. Otherwise, even generated by the Flying line, it is useless
The Flying line controls the Hidden line: if the Hidden line is Weak it is to be thrown away; if the Hidden line is Prosperous, wait for the moment the Flying line is clashed and the matter succeeds — but before it succeeds the matter is held down, and the manner of the holding down is like that of the line.
The Flying line generates the Hidden line: good, if it is not Rootless; but one must look at whether the Hidden line has any other relation, for example being in the Tomb at the Flying line in the case of Metal
The Hidden line generates the Flying line: this is a case of draining. If the Hidden line is Prosperous it does not matter, and one waits for the moment the Flying line is clashed, provided the Flying line is not harmed; if it is Resting–Confined it is spoilt outright. But this is a case where, even if it succeeds, there is a loss
The Hidden line controls the Flying line: as with the relation between a changed line and a moving line, only the Flying line acts on the Hidden line and not the other way round; one still waits for the clash, provided the Flying line is not harmed.

Cases where the Hidden line is useless

The Hidden line is Void
The Hidden line is in the Tomb twice over, at the Day and at the Flying line
The Hidden line is Weak and drained, or in the Tomb or at Extinction at the Flying line
The Hidden line together with the Flying line and the Day, the Month or a moving line makes up the Three Punishments
It is Weak and harmed by the Flying line besides

In the case where the Hidden line appears, we still read the Hidden line as being in Hidden movement and acting on the other lines like a line in Hidden movement — but this counts only in the case of finding a Hidden line to refer to.