Zi Wei Dou Shu: How to Cast a Chart and the Meaning of the 12 Palaces

Tử Vi (Vietnamese astrology) chart construction: how to cast a chart and the meaning of the twelve palaces

What are the steps for casting a Tử Vi chart?

Casting a Tử Vi chart takes nine steps in order. Each step below states the rule and then illustrates it with a chart for a fictional person. If you want an overview of this subject first, please read What Is Vietnamese Astrology? An Overview of Reading Methods and Foundational Concepts.

Step 1: How do you convert a solar birth date and time into the lunar calendar?

Convert the solar date to a lunar date using the calendar algorithm computed for the Vietnam time zone (UTC+7). The year used to take the can chi (heavenly stem and earthly branch) is the lunar year, so a person born before Tết belongs to the previous can chi year. The birth hour is converted into one of the twelve earthly branch hours according to Vietnam clock time, as in the table below.

For a person born between 23h and midnight, the books differ: some count it as the next day, some keep the old day. This is a variant reading. The way of counting leap months is also a variant reading: the site's calculation core places it according to the month number of the leap month as if it were an ordinary month with the same number, while Đẩu số tinh thành splits it in half, counting the first half of the leap month as the previous month and from the 16th as the following month.

The example chart is for a fictional person: male, born 15/3/1990 solar, at the Ngọ hour. Converted to the lunar calendar, this is the 19th day of the 2nd month of the year Canh Ngọ, that is, Dương Nam (yang male).

Step 2: How do you place the Mệnh palace and the Thân palace in the right direction?

From the Dần palace as the first month, count clockwise to the lunar birth month. Take that palace as the Tý hour: count counter-clockwise to the birth hour for the Mệnh palace, count clockwise to the birth hour for the Thân palace. Mệnh runs counter-clockwise, Thân runs clockwise, from the same point. The book Đẩu số tinh thành also records these two directions correctly, so this is a point on which the common books agree.

For the example chart: for the 2nd lunar month, the month palace is Mão. With the Ngọ hour, Mệnh is at Dậu and Thân is at Dậu, that is, Thân resides in Mệnh. For a birth in the 3rd month at the Ngọ hour, the month palace is Thìn, Mệnh is at Tuất, Thân is at Tuất, because the Tý hour and the Ngọ hour always give Mệnh and Thân in the same palace. If it is the same 3rd month but born at the Dần hour, then Mệnh is at Dần and Thân is at Ngọ.

Where does the Thân palace reside according to the birth hour?

The Thân palace is not used to determine the Quan Lộc or Tài Bạch palace. It is an additional palace to read, overlapping one of six palaces according to the birth hour, as in the table at the end of the article. For instance, at the Tý hour and the Ngọ hour, Thân resides in Mệnh; at the Dần hour and the Thân hour, Thân resides in Quan Lộc; at the Tỵ hour and the Hợi hour, Thân resides in Phu Thê.

Step 3: In which direction are the twelve palaces placed?

From the Mệnh palace, go counter-clockwise, that is, against the clock on the earthly plate, in the order Mệnh, Huynh Đệ, Phu Thê, Tử Tức, Tài Bạch, Tật Ách, Thiên Di, Nô Bộc, Quan Lộc, Điền Trạch, Phúc Đức, Phụ Mẫu. Therefore Huynh Đệ sits in the cell immediately before the Mệnh palace, and Phụ Mẫu in the cell immediately after. The earthly plate of twelve branches stands fixed and runs clockwise, while the palace names rotate according to the position of the Mệnh palace. The book Đẩu số tinh thành also records the twelve palaces running counter-clockwise from Mệnh, so this is a point on which the common books agree. The palace name here uses the word Tử Tức as on the site's charts; some books call it Tử Nữ, and the two names refer to the same palace.

For the example chart, placing them counter-clockwise from Mệnh at Ất Dậu gives: Mệnh at Ất Dậu, Huynh Đệ at Giáp Thân, Phu Thê at Quý Mùi, Tử Tức at Nhâm Ngọ, Tài Bạch at Tân Tỵ, Tật Ách at Canh Thìn, Thiên Di at Kỷ Mão, Nô Bộc at Mậu Dần, Quan Lộc at Kỷ Sửu, Điền Trạch at Mậu Tý, Phúc Đức at Đinh Hợi, Phụ Mẫu at Bính Tuất.

Step 4: Where is the cục determined from?

The cục is not calculated from the birth year and birth day but from the nạp âm (sound element) of the can chi of the Mệnh palace. The can of the palaces is taken according to the Ngũ Hổ Độn from the birth year's can, counting clockwise from the Dần palace: for a Giáp or Kỷ year, Dần carries Bính; for an Ất or Canh year, Dần carries Mậu; for a Bính or Tân year, Dần carries Canh; for a Đinh or Nhâm year, Dần carries Nhâm; for a Mậu or Quý year, Dần carries Giáp. Tý and Sửu carry the can continuing from Tuất and Hợi. Whichever element the nạp âm of the can chi of the Mệnh palace belongs to gives that cục: Thủy nhị cục is 2, Mộc tam cục is 3, Kim tứ cục is 4, Thổ ngũ cục is 5, Hỏa lục cục is 6. This way of determining the cục is the same in the common books. To look closely at the first three lines of a chart, which are âm dương nam nữ, cục, and nạp âm, please read the first three lines of a chart, and the can of the twelve palaces.

For the example chart: the year is Canh, so the Dần palace carries the can Mậu. The Mệnh palace is Ất Dậu, whose nạp âm is Tuyền Trung Thủy, so the chart is Thủy nhị cục. The table of cục according to birth year can and Mệnh palace at the end of the article is for quick lookup.

Step 5: How is the Tử Vi star placed according to the cục and birth day?

Tử Vi is placed according to the cục number and the lunar birth day, not according to the month. Find the smallest number divisible by the cục number that is not less than the birth day; the quotient tells you how many palaces to count from the Dần palace, treating Dần as 1, clockwise. The remainder, that is, that number minus the birth day, if odd means go back, if even means go forward that many palaces from the palace just counted to. The book Đẩu số tinh thành records the same method, so this is a point on which the common books agree.

A few examples according to the calculation core: cục 2 day 1 gives Tử Vi at Sửu; cục 2 day 2 gives Tử Vi at Dần; cục 3 day 1 gives Tử Vi at Thìn; cục 4 day 10 gives Tử Vi at Ngọ; cục 6 day 1 gives Tử Vi at Dậu; cục 5 day 17 gives Tử Vi at Dần. For the example chart, cục 2 and day 19 give Tử Vi at Tuất, Thiên Phủ at Ngọ. The table for placing Tử Vi according to the cục and birth day at the end of the article is for quick lookup.

Step 6: How are the fourteen main stars placed?

The Tử Vi group consists of six stars, running counter-clockwise from Tử Vi: Tử Vi, Thiên Cơ 1 palace counter-clockwise, Thái Dương 3 palaces counter-clockwise, Vũ Khúc 4 palaces counter-clockwise, Thiên Đồng 5 palaces counter-clockwise, Liêm Trinh 8 palaces counter-clockwise. The Thiên Phủ group consists of eight stars, and Thiên Phủ is symmetric with Tử Vi across the Dần Thân axis, so when Tử Vi is at Dần or Thân, Thiên Phủ is in the same palace. From Thiên Phủ going clockwise: Thiên Phủ, Thái Âm 1 palace clockwise, Tham Lang 2 palaces clockwise, Cự Môn 3 palaces clockwise, Thiên Tướng 4 palaces clockwise, Thiên Lương 5 palaces clockwise, Thất Sát 6 palaces clockwise, Phá Quân 10 palaces clockwise. That is fourteen main stars in total. Thiên Cơ belongs to the Tử Vi group, and Thiên Phủ heads the Thiên Phủ group. The method of placing the fourteen main stars is the same in the common books. The table of the distance of each star at the end of the article is for quick lookup.

For the example chart: Tử Vi is at Tuất, so Thiên Cơ is at Dậu and Cự Môn is at Dậu, that is, Mệnh at Ất Dậu has Thiên Cơ and Cự Môn. The remaining palaces in turn have Tham Lang at Giáp Thân, Thái Dương and Thái Âm at Quý Mùi, Vũ Khúc and Thiên Phủ at Nhâm Ngọ, Thiên Đồng at Tân Tỵ, Phá Quân at Canh Thìn, Kỷ Mão with no main star, Liêm Trinh at Mậu Dần, Kỷ Sửu with no main star, Thất Sát at Mậu Tý, Thiên Lương at Đinh Hợi, Tử Vi and Thiên Tướng at Bính Tuất.

Steps 7 and 8: How are the star cycles, auxiliary stars, and the Four Transformations assigned?

After the main stars, the Lộc Tồn cycle is placed according to the year can, the Tràng Sinh cycle is started according to the cục with Dương Nam and Âm Nữ going clockwise and Âm Nam and Dương Nữ going counter-clockwise, the Thái Tuế cycle always runs clockwise from the year branch, and then the auxiliary stars. After that, the Four Transformations are assigned according to the birth year can. This is also the order that Đẩu số tinh thành and the common books use, so there is mostly agreement.

For the Four Transformations of the can Canh alone, there are three versions. The table the site uses gives Thiên Đồng transforming into Khoa and Thái Âm transforming into Kỵ, while Thái Dương transforms into Lộc and Vũ Khúc transforms into Quyền. Đẩu số tinh thành and Từ Tăng Sinh record Thái Âm transforming into Khoa and Thiên Đồng transforming into Kỵ. Vương Đình Chi records Thiên Phủ transforming into Khoa and Thiên Đồng transforming into Kỵ. This is a variant reading, not a place where one side is wrong. The other cans also have variant readings at Tân and Nhâm. To see all the tables, please read Four Transformations.

For the example chart, which is a Canh year, according to the site's table Thái Dương transforms into Lộc at Quý Mùi, Vũ Khúc transforms into Quyền at Nhâm Ngọ, Thiên Đồng transforms into Khoa at Tân Tỵ, and Thái Âm transforms into Kỵ at Quý Mùi.

Step 9: Where do the major periods start and in which direction do they run?

The major periods start from the Mệnh palace, not from the Thân palace. The starting age, calculated by tuổi mụ (the nominal age), is exactly the cục number. Each major period is ten years. Dương Nam and Âm Nữ go clockwise, Âm Nam and Dương Nữ go counter-clockwise. This is a point on which the common books agree. To look more closely, please read What Is a Great Limit in Vietnamese Astrology, Which Palace Does It Start From, Which Direction Does It Move, and at What Age Does It Begin?.

For the example chart: it is Dương Nam, so the major periods run clockwise, and the first four major periods are ages 2 to 11 at Mệnh in Dậu, ages 12 to 21 at Phụ Mẫu in Tuất, ages 22 to 31 at Phúc Đức in Hợi, ages 32 to 41 at Điền Trạch in Tý. Please note that tiểu hạn and lưu niên are not the natal chart: the natal chart is fixed, while tiểu hạn and lưu niên are yearly layers placed over that chart.

How can you check it yourself?

Please go to the Tử Vi chart tool, cast your own chart, and compare it step by step. If you want to read the meaning of each palace, this article does not go deep into it; please see the separate articles such as The Destiny Palace in Zi Wei Dou Shu: Meaning and Interpretation and the articles in the same series for the remaining eleven palaces.

Are Mệnh and Thân, the twelve palaces, the cục, and the fourteen main stars the same in every book?

For these four parts, the common books place them the same way. Where the books differ is the Four Transformations of the cans Canh, Tân, and Nhâm, the way of counting leap months, and the birth day of a person born between 23h and midnight. When you meet these four points, you should know which version you are following, rather than treating one version as absolutely correct.

This article only discusses how to cast a chart and the order of the steps, and asserts nothing about the destiny, finances, or health of anyone. A chart is a description of tendencies, not a fixed verdict.

Reference tables for the chart casting steps according to Nhật Nguyệt's calculation core

The tables below are computed by exactly the placement method that the site's Tử Vi chart tool uses. Month and day are lunar month and day.

Mệnh palace according to birth month and birth hour

Where does the Thân palace reside according to the birth hour?

Cục according to birth year can and Mệnh palace

The number in the cell is the cục number: 2 Thủy nhị cục, 3 Mộc tam cục, 4 Kim tứ cục, 5 Thổ ngũ cục, 6 Hỏa lục cục.

Palace for placing Tử Vi according to the cục and birth day

How many palaces is each of the fourteen main stars from the head of its group?