TL;DR: Tử Vi Đẩu Số has many branches, notably the Tam Hợp school (orthodox, emphasizing the three directions and four cardinal points and a full set of stars), the Tứ Hóa school including Phi Tinh and Khâm Thiên (focusing on the Tứ Hóa cycle and star transformation according to can), the Trung Châu school of Vương Đình Chi (using lưu Thái Tuế instead of tiểu hạn, adding stars according to the can of the đại vận palace), and the Tân Biên style, popularized in Vietnam by cụ Thiên Lương. The same chart read by different schools yields different results because they differ on three core points: the set of stars used, the method of placing Tứ Hóa according to the birth year can (especially the can Canh, Tân, Nhâm), and the method of starting tiểu hạn or lưu niên. For the can Canh, all versions give Thái Dương Hóa Lộc and Vũ Khúc Hóa Quyền, differing only in the pair Hóa Khoa and Hóa Kỵ: the chart utility table on the site uses Thiên Đồng Hóa Khoa and Thái Âm Hóa Kỵ, while Đẩu số tinh thành tập 1 and Từ Tăng Sinh's book reverse these two stars, and the Trung Châu school of Vương Đình Chi, according to its own transmission, keeps Thiên Đồng Hóa Kỵ. No school holds absolute truth; each is a system of conventions with its own internal logic.
Which schools of Tử Vi exist, and why do different schools read the same chart differently?
The legend of Trần Đoàn and the Toàn Thư: what can be verified, and what cannot?
Tử Vi Đẩu Số (紫微斗數, Zǐwēi Dǒushù, literally "the number of the stars of the Purple Star") is a Chinese system of astrology and fate reading, using a twelve-palace chart with more than a hundred named stars to analyse a person's destiny based on their date and hour of birth. It is one of the two most widespread systems of natal astrology in China, alongside Bát Tự Tứ Trụ (BaZi, the Four Pillars).
According to legend, Tử Vi Đẩu Số was founded by Trần Đoàn (陳摶, roughly 871 to 989), a Daoist priest and scholar of the late Five Dynasties and early Song period. He lived in seclusion for most of his life on Mount Hua. However, it must be said plainly: directly attributing Tử Vi Đẩu Số to Trần Đoàn cannot be verified historically. Modern researchers hold that this attribution reflects the system's origins in a Song-era synthesis of Daoist cosmology, astronomical observation and fate calculation. The cosmological foundations on which Tử Vi Đẩu Số rests, including the Heavenly Stems, Earthly Branches, the Five Elements, yin and yang, and the system for dividing the celestial bodies around the north celestial pole, were already established by the Han period (206 BCE to 220 CE).
The books regarded as the foundation of this discipline, Tử Vi Đẩu Số Toàn Thư and Tử Vi Đẩu Số Toàn Tập, are in a similar situation: they were handed down through many generations of copying and supplementation, so it is very difficult to determine which layer of text is the original. Therefore, when a school says "the ancient texts record that", we should understand this as a convention internal to that school, not as historical evidence that has been verified.
Why do different schools read the same chart differently?
The short answer: because the schools do not share a single set of conventions. The three differences below explain almost the entire divergence.
First, they use different sets of stars. Some schools use only a few dozen main stars, others use more than a hundred, and still others add minor stars that other schools do not place. For example, the Trung Châu school places a number of minor stars differently from the Nam school, such as Nguyệt Giải, Thiên Vu, Thiên Nguyệt and Âm Sát; and it places the two stars Linh Tinh and Hỏa Tinh in the forward direction for both yin males and yang females, unlike the traditional placement.
Second, they place the Tứ Hóa (Four Transformations) according to the stem of the birth year differently. This is the most contentious point, especially for the stems Canh, Tân and Nhâm.
Third, they read the periods of fortune differently: some schools use tiểu hạn (minor limits), some use lưu Thái Tuế (the flowing Year Star), and some use both but weight them differently.
The main schools and their characteristics
The Tam Hợp school
The Tam Hợp school takes traditional Tử Vi as the orthodox line. The differences of an orthodox line tend to form a complete system, because it was developed within the Khâm Thiên Giám, the court agency devoted to the study of meteorology and astronomy, and was regularly applied to readings for officials and emperors. In the Ming dynasty, transmission within the Tam Hợp school became closed, passed only from a master to a single disciple; later scholars such as Du Chính Tiếp continued to develop and preserve it, helping this school survive into the 20th century through masters such as Lục Bân Triệu and Vương Đình Chi.
As for its origins, one theory holds that it began in Trung Châu, Luoyang, with the founding masters Bạch Ngọc Thiềm (1194 to 1229) and Ngô Cảnh Loan. Ngô Cảnh Loan, courtesy name Trọng Tường, is said by legend to have had a grandfather, Ngô Pháp Vượng, who served as a national geomantic master during the Southern Tang; his father was Ngô Khắc Thành, a student of Hi Di Trần Đoàn. These are legendary details, not verified historical records.
The diagnostic characteristic of the Tam Hợp school is its emphasis on the tam phương tứ chính (the three harmonising palaces and the opposite palace), on reading the configuration of star combinations, and on using the full set of stars.
The Tứ Hóa school: Phi Tinh and Khâm Thiên
The Tứ Hóa school takes the cycle of the Four Transformations (Hóa Lộc, Hóa Quyền, Hóa Khoa, Hóa Kỵ) as the axis of its readings. Within it, the Phi Tinh branch uses the technique of flying the Four Transformations from one palace to another to trace the causal relationships between palaces; the Khâm Thiên branch is tied to the tradition of the Khâm Thiên Giám, emphasising the palace stem and the Four Transformations of the major limit and the flowing year.
According to the book TVĐS Mệnh vận phân tích by Từ Tăng Sinh, to read Tứ Hóa Phi Tinh one must persistently test the combinations of stars, transformed stars, palace positions and the flying Four Transformations across many kinds of situation, then use analogy, deduction and induction to establish rules. In the same book, the author lists a whole series of Tử Vi Đẩu Số schools existing today, including the Thấu school, the Chiêm nghiệm school, the Tứ Hóa Phi Tinh school, the Quá cung school, the Tiểu hạn school, the Côn Luân school and the Lạc Dương school. According to the author, each school has its own rules for reading fate, and no school is entirely like another: for instance, some schools look only at tiểu hạn and ignore the flowing year, others use the flying stars of the flowing year, while some schools study only star combinations and never discuss the Four Transformations at all.
The Trung Châu school of Vương Đình Chi
The Trung Châu school has a very detailed and flexible way of reading periods of fortune. According to a summary on the Lý số Việt Nam forum, the major limit palace of this school carries the flowing stars and the Four Transformations of the major limit; the flowing year palace carries the flowing stars and the Four Transformations of the flowing year. The method of placing stars and the Mệnh and Thân palaces are similar to the Nam school, differing only in that the two stars Linh Tinh and Hỏa Tinh are placed in the forward direction for both yin males and yang females.
A distinctive point: the major limit palaces of Trung Châu are assigned heavenly stems according to the month of the birth year. The Dần palace on the chart is month 1, the Mão palace month 2, and so on. For example, in years of Giáp and Kỷ, the first month has the stem Bính, so the Dần palace on the chart has the stem Bính, the Mão palace has the stem Đinh, and the Thìn palace has the stem Mậu. In years of Ất and Canh, the Dần palace is Mậu, the Mão palace is Kỷ, and the Thìn palace is Canh. The stem of the palace is used as the basis for determining the important flowing stars of the major limit, such as Lộc Tồn, Kình Dương, Đà La and the Four Transformations.
One further point: Trung Châu treats the current major limit palace as the flowing Mệnh palace of the major limit, and the other palaces such as parents, wealth and career are also determined from that flowing Mệnh palace. For example, a person currently in the major limit from age 24 to 33 at the Ngọ palace has the Ngọ palace as the flowing Mệnh, the Mùi palace as the flowing Phụ Mẫu, and the Thân palace as the flowing Điền Trạch. This school does not use the tiểu hạn palaces or the flowing major limit. To read a single year's fortune, it takes the palace containing the flowing Thái Tuế as the flowing year, treating it as the flowing Mệnh palace of that year; the remaining palaces likewise shift to become the flowing Phụ Mẫu, the flowing Điền Trạch. The flowing stars of the year are based on the stem and branch of the year being read, similar to the Nam school.
As for the stars, the book Vương Đình Chi đàm Đẩu Số shows a very fine-grained analysis position by position. For instance, Thiên Cơ at Sửu and Mùi is considered fallen and obscured, its power of movement much reduced; to bring out its analytical capacity it is best to meet Xương and Khúc. If it meets Hóa Kỵ, its analytical power weakens. At Tị and Hợi it is middling, and seeing Thái Âm in the opposite palace can draw off the influence of Thiên Cơ, turning its power of movement into consumption. The book also cites an old verse: when the Mệnh palace sits at Tị or Hợi with Thiên Cơ holding it, a person may find it easy to build a career in a foreign land and live in sufficiency, yet their nature still carries a heavy streak of cunning (the original reads "Thiên Cơ tị hợi cung Mệnh phùng, hảo ẩm ly tông gian giảo trọng"). For the Cơ Lương configuration holding the Mệnh, the book gives three different old commentaries for three variant configurations, showing that with the same star combination the conclusion can reverse depending on which star is stronger.
On the Four Transformations, Vương Đình Chi, founder of the Trung Châu school, by private transmission keeps Thiên Đồng as Hóa Kỵ for the stem Canh, meaning this school's Tứ Hóa table differs from the table used by the site's chart tool. He cites a line in the Toàn Thư saying that for Thiên Đồng at Hợi, a person born in a Canh year has Thiên Đồng as Hóa Kỵ, and is therefore ranked in a lower configuration, to argue for keeping Thiên Đồng as Hóa Kỵ. In the book Vương Đình Chi đàm Đẩu Số, he also recounts that he once read for a reader of a weekly magazine, looked at the chart and asked the person outright whether they were thinking of suicide, which made the person weep and confirm it; from this he argues that the Trung Châu transmission shows itself to be more reasonable in places than the Mân school, and advises students not to be bound by the doctrines of their own faction, assigning the word "fortune star" to Thiên Đồng the moment they see it.
The Tân Biên approach and Master Thiên Lương in Vietnam
In Vietnam, the Tân Biên approach associated with the name of Master Thiên Lương is the current popular in chart-lookup tools. This is a line influenced by a modernising approach, simplifying a number of auxiliary star cycles and emphasising practical usability for ordinary users. It should be noted: this is a highly localised branch, not identical with any of the Chinese schools above.
Comparison table of the schools
| School | Main source books | Set of stars used | Method of reading periods of fortune | Role of the Four Transformations |
|---|---|---|---|---|
| Tam Hợp | Tử Vi Đẩu Số Toàn Thư, Toàn Tập | Full set of stars, emphasis on main and auxiliary stars | Tam phương tứ chính, configurations | Important but not the sole axis |
| Tứ Hóa (Phi Tinh) | TVĐS Mệnh vận phân tích (Từ Tăng Sinh) | Stars, transformed stars, palace positions | Flying the Four Transformations between palaces, tracing cause and effect | The main axis of the whole reading |
| Tứ Hóa (Khâm Thiên) | Tradition of the Khâm Thiên Giám | Full set of stars | Palace stem of the major limit, flowing year | Central, using both the major limit and flowing year Four Transformations |
| Trung Châu (Vương Đình Chi) | Vương Đình Chi đàm Đẩu Số | Full set of stars, with additional minor stars; Linh Tinh and Hỏa Tinh placed forward for both yin males and yang females | Flowing Thái Tuế as the year's flowing Mệnh; no tiểu hạn; major limit palace stems assigned by birth month | Central, using the major limit and flowing year Four Transformations |
| Tân Biên, Master Thiên Lương | Widely available Tân Biên materials in Vietnam | Simplified, with some auxiliary star cycles removed | Tiểu hạn and flowing year in the Vietnamese manner | Used, but with emphasis on practical application |
Three specific differences encountered in chart-lookup tools
The Four Transformations for the stems Canh, Tân and Nhâm
This is the classic point of contention. For the stem Canh, all versions agree on two things: Thái Dương as Hóa Lộc and Vũ Khúc as Hóa Quyền. The difference between versions lies only in the pair Hóa Khoa and Hóa Kỵ. At least three versions are in circulation:
- The first version, which is also the table used by the site's chart tool: Thái Dương as Hóa Lộc, Vũ Khúc as Hóa Quyền, Thiên Đồng as Hóa Khoa, Thái Âm as Hóa Kỵ. This is the widely transmitted version, and Vương Đình Chi himself calls this "Dương Vũ Đồng Âm" version the transmitted one.
- The second version, recorded in Đẩu số tinh thành volume 1 in the Tứ Hóa placement table and in the mnemonic "Canh Dương Vũ Âm Đồng", together with the book TVĐS Mệnh vận phân tích by Từ Tăng Sinh: Thái Âm as Hóa Khoa, Thiên Đồng as Hóa Kỵ. That is, the two stars Khoa and Kỵ swap places relative to the first version.
- The third version, that of Vương Đình Chi, founder of the Trung Châu school, by private transmission: Thiên Phủ as Hóa Khoa, Thiên Đồng as Hóa Kỵ.
It must be said plainly: the table used by the site's chart tool (Thiên Đồng as Hóa Khoa, Thái Âm as Hóa Kỵ for the stem Canh) is a decision of the site's coordinator. That table should not be called the "Trung Châu approach", because Vương Đình Chi uses Thiên Đồng as Hóa Kỵ, which differs from the site's table.
The stems Tân and Nhâm also have variant versions among the schools, but this time there is no source specifying exactly which star changes for which, so the article only notes that variants exist and does not list them.
Because the Four Transformations bear directly on readings of wealth, career and disputes, a difference in a single star is enough to change the conclusion entirely in direction.
How tiểu hạn is started
Some schools start tiểu hạn according to sex and the yin or yang of the birth year, going forward or backward from the Mệnh palace; some schools start from another palace. The Trung Châu school drops tiểu hạn altogether and uses the flowing Thái Tuế. So when two chart-lookup tools give two different tiểu hạn palaces for the same year, we are seeing two different conventions, not one side being wrong.
The number of stars used
Some schools use only a few dozen main stars; some place dozens of additional minor stars. The more stars there are, the more detailed the reading, but the more prone it is to internal contradiction if the reader does not grasp the order of priority among the stars. The book Tử Vi kinh nghiệm quyển hạ shows the extreme detail of the method that places auxiliary stars onto individual body parts (Thiên Khôi for the head, Thiên Tướng for the face, Thái Dương for the right eye, Thái Âm for the left eye, Cự Môn for the mouth, Hóa Kỵ for the tongue, and many other stars), and these stars, when they sit in Mệnh, Giải Ách or Lục Hợp and meet Kình, Hình or Kỵ, are read as a tendency to scars or marks on the corresponding body part. This is the kind of reading that exists only in the schools using a very full set of stars.
So which school should one choose?
There is no absolute answer. Each school is a system of conventions with its own internal logic, and the correctness of a school has meaning only within that system of conventions. What matters when looking up a chart is knowing clearly which school the tool you are using follows, so as not to mix the rules of one school into another. Mixing is the most common cause of confusion among students: with the same chart, taking the Four Transformations according to school A but reading the periods of fortune according to school B will almost certainly produce a contradiction.
For a beginner, the practical approach is to choose one school, learn its system of conventions thoroughly, and only then expand to another school for comparison. The conclusions of Tử Vi Đẩu Số should also not be treated as absolute statements about finances, health or destiny; they are a frame of reference for self-observation, not a verdict.
