TL;DR: Tam Phuong Tu Chinh is the set of four key palaces used to read any one palace in Tử Vi: the home palace, its two Tam Hop palaces (linked by Earthly Branch) and the opposite palace. Many texts also weigh the two flanking palaces (Giap) and the Nhi Hop palace, because neighbours can support or squeeze the home palace. Schools disagree on ranking: some rate the opposite palace above Tam Hop, some drop Nhi Hop almost entirely, and the Khâm Thiên school reads palace relations through the flight paths of Tứ Hóa instead of star convergence.
What is Tam Phuong Tu Chinh?
Tam Phuong Tu Chinh is the four key palaces used to interpret one palace on a Tử Vi chart: the home palace, the two Tam Hop palaces that share its Earthly Branch group, and the opposite palace. In the common presentation, every palace on the chart has its own Tam Phuong Tu Chinh, and reading all four gives a fuller result than reading one alone. "Tam Phuong" means the two Tam Hop palaces, "Tu Chinh" means the opposite palace. Home palace plus two Tam Hop palaces plus the opposite palace make four.
This mechanism comes from how stars are placed by Earthly Branch. Each palace carries one Earthly Branch, and the relations between Earthly Branches decide which palace combines with which, and which opposes which.
How are Tam Hop and the opposite palace determined?
Tam Hop has four fixed groups:
- Than, Ty, Thin
- Ty, Dau, Suu
- Dan, Ngo, Tuat
- Hoi, Mao, Mui
For example, if the Menh palace carries the Earthly Branch Ngo, its two Tam Hop palaces are Dan and Tuat. The opposite palace is the one facing it on the board, in six pairs: Ty with Ngo, Suu with Mui, Dan with Than, Mao with Dau, Thin with Tuat, Ty with Hoi. A Menh palace at Ngo opposes the palace at Ty, usually the Thiên Di palace.
What are the 12 palaces in Tam Hop, opposite, Giap, and Nhi Hop?
The table below follows the palace calculation core in tuvi_chieusau.go (functions HoiSao, LienCung): for each palace, take its Earthly Branch and derive the two Tam Hop palaces, the opposite palace, the two flanking palaces before and after, and the Nhi Hop palace. The "Tam Hop" column lists the two Earthly Branches that combine with the home palace, "opposite" lists the facing branch, "Giap" lists the two neighbouring branches, "Nhi Hop" lists the Nhi Hop branch.
| Home palace (Earthly Branch) | Two Tam Hop palaces | Opposite palace | Two Giap palaces | Nhi Hop palace |
|---|---|---|---|---|
| Ty | Than, Thin | Ngo | Hoi, Suu | Suu |
| Suu | Ty, Dau | Mui | Ty, Dan | Ty |
| Dan | Ngo, Tuat | Than | Suu, Mao | Hoi |
| Mao | Hoi, Mui | Dau | Dan, Thin | Tuat |
| Thin | Ty, Than | Tuat | Mao, Ty | Dau |
| Ty | Dau, Suu | Hoi | Thin, Ngo | Than |
| Ngo | Dan, Tuat | Ty | Ty, Mui | Mui |
| Mui | Hoi, Mao | Suu | Ngo, Than | Ngo |
| Than | Ty, Thin | Dan | Mui, Dau | Ty |
| Dau | Ty, Suu | Mao | Than, Tuat | Thin |
| Tuat | Dan, Ngo | Thin | Dau, Hoi | Mao |
| Hoi | Mao, Mui | Ty | Tuat, Ty | Dan |
One distinction matters: the table is written by the Earthly Branch of the palace, not by palace name (Menh, Tai, Quan and so on). Palace names change with birth hour and birth month, while Earthly Branch relations are fixed. To look up the Tam Phuong Tu Chinh of the Menh palace, you first need to know which Earthly Branch the Menh palace sits in.
How strongly does each type of palace act?
There is no absolute scale, but the common presentation gives a rough order: the home palace is the root, the two Tam Hop palaces converge into it, the opposite palace stands against it, the two Giap palaces squeeze it from both sides, and the Nhi Hop palace supports it more lightly.
The home palace
The home palace is where the main stars sit, and it is the root of interpretation. Every other palace only means something when placed beside the home palace.
The two Tam Hop palaces
In the interpretive tradition, stars in a Tam Hop palace have a strong and long-lasting influence. For example, the Tài Bạch palace sits in a fixed Tam Hop position with the Menh palace, so stars in Tài Bạch converge on Menh throughout life, and the good or bad of Tài Bạch acts directly on Menh, and the reverse as well. The Quan Lộc palace is called the "khi so palace" of Menh, speaking of career and rank. The Thiên Di palace is the outward expression of Menh.
The opposite palace
The opposite palace is the one facing the home palace, acting face to face. The book Đẩu Số Tinh Thanh (Thiên Hỏa Đồng Nhân) clearly separates two actions: stars in the Tam Phuong of the home palace are said to "hoi", stars in the opposite palace are said to "chieu". So "hoi" and "chieu" are two different mechanisms, not lumped together. This book also names "phu" and "giap": auspicious stars in the two neighbouring palaces are called phu, inauspicious stars in the two neighbouring palaces are called giap. Both auspicious and inauspicious stars in the two adjacent palaces are called giap, for example nhat nguyet giap Menh, khong kiep giap Menh.
The two Giap palaces
The two Giap palaces are the ones immediately before and after the home palace. The book TVDS Menh Van Phan Tich (Từ Tăng Sinh) argues that earlier interpreters only noted stars in the same palace or patterns from Tam Phuong and forgot the force of the flanking palaces, but by the author's and colleagues' testing the force of the two flanks cannot be ignored: if auspicious stars flank the palace they lift it, if inauspicious stars flank it the outlook is poor. The book also gives the example of the Huynh Đệ and Phụ Mẫu palaces holding auspicious Phu, Bat, Xuong, Khuc, Duong, Am or the three Hóa Lộc, Quyen, Khoa flanking Menh, in which case the original Menh palace or the Menh palace of the major limit is helped, and even a weak Menh can pass the gate.
An extreme example mentioned in the Tử Vi essay collection is "Dương Đà giap Ky": when Hóa Kỵ sits in the Menh palace with Kình Dương and Đà La on either side, it creates double pressure and easily leads to ruin. This reading shows that Giap palaces can amplify or suppress the home palace.
The Nhi Hop palace
The Nhi Hop palace is the one whose Earthly Branch is Nhi Hop with the home palace. In the table above, each palace has its own Nhi Hop palace. This is the lightest layer of relation and also the most disputed, since many schools barely use it when reading Tam Phuong Tu Chinh.
Where do the schools disagree?
This point needs stating clearly, because the same chart giving different results across schools is mostly due to different ranking of the palace layers.
Some schools rate the opposite palace above Tam Hop
Some schools place the opposite palace ahead of Tam Hop, on the grounds that the opposite palace acts head-on while Tam Hop acts by convergence. This view differs from the common presentation in the interpretive tradition, where Tam Hop is stressed as strong and lasting throughout life. Vương Đình Chi's book on Đẩu Số, discussing Liêm Trinh and the Sát Phá Tham group, also says one must consider the rotating major limit, then see what stars converge into the Menh palace through Tam Phuong Tu Chinh, and only then decide whether the change is good or bad. This wording puts Tam Phuong Tu Chinh in the role of a sufficient condition for a conclusion, rather than itself asserting fortune or misfortune.
Some schools drop Nhi Hop almost entirely
Many schools reading Tam Phuong Tu Chinh use only four palaces: home, two Tam Hop, one opposite, plus the two Giap as a secondary layer. The Nhi Hop palace is hardly entered into the reading table, or mentioned only as a pure Earthly Branch relation. The reason is that Nhi Hop creates neither the convergence of Tam Hop nor the opposition of the opposite palace, so its effect is weak and easily overshadowed.
The Khâm Thiên school reads palace relations through Tứ Hóa flight paths
The Khâm Thiên Tứ Hóa school does not stop at star convergence by Tam Phuong Tu Chinh, but reads relations between palaces through the flight paths of Tứ Hóa. The method: take the stem of each palace, project Hóa Lộc, Hóa Quyền, Hóa Khoa, Hóa Kỵ onto other palaces, then follow the chain of khi Ky as it spreads. The Khâm Thiên Tứ Hóa essay collection cites a female chart with uterine fibroids: the Phúc Đức palace with stem Mau projects Thiên Cơ Hóa Kỵ into Phu Thê, from Phu Thê the khi moves on so that Thái Dương meets Cung Môn Hóa Kỵ of the birth year, creating double Ky at Tài Bạch, then Tài Bạch opposes back to Phúc Đức; adding other Ky flows entering Tật Ách and Tật Ách self-transforming Ky outward, it becomes a four-Ky destructive configuration. This reading rests not on star convergence by Tam Phuong Tu Chinh but on the path of Hóa Kỵ between palaces.
Vương Đình Chi's book on Đẩu Số also stresses the role of Tứ Hóa: without the action of Tứ Hóa a tendency is only an "an tuong" in the mind and hard to become an acted phenomenon; with Tứ Hóa urging it, it becomes a "hinh anh hien lo".
What is Tam Phuong Tu Chinh of typical palaces?
According to the general interpretive tradition:
- Menh palace: Thiên Di, Quan Lộc, Tài Bạch. Thiên Di is the outward expression, Quan Lộc is the career khi so, Tài Bạch is the source of nurture.
- Phụ Mẫu palace: Tật Ách, Nô Bộc, Tử Tức. When reading relations with parents one must also note the Phúc Đức palace, since the fortune or misfortune of Phúc Đức strongly affects harmony or clash with parents.
- Phúc Đức palace: Tài Bạch, Phu Thê, Thiên Di. If inauspicious stars land in a Tam Hop palace, Phúc Đức carries part of it too.
- Điền Trạch palace: Tử Tức, Huynh Đệ, Tật Ách.
- Quan Lộc palace: Phu Thê, Tài Bạch, Menh.
- Nô Bộc palace: Huynh Đệ, Tử Tức, Phụ Mẫu.
- Thiên Di palace: Menh, Phu Thê, Phúc Đức.
- Tật Ách palace: Phụ Mẫu, Huynh Đệ, Điền Trạch. Constitution is largely inherited from parents, so the opposite Phụ Mẫu palace is read alongside.
- Tài Bạch palace: Phúc Đức, Quan Lộc, Menh.
- Tử Tức palace: Điền Trạch, Nô Bộc, Phụ Mẫu.
- Phu Thê palace: Quan Lộc, Phúc Đức, Thiên Di.
- Huynh Đệ palace: Nô Bộc, Điền Trạch, Tật Ách.
Comparing with the Earthly Branch table above shows the two ways of writing match: for example, a Menh palace at Ngo has Tam Phuong Tu Chinh by palace name of Thiên Di, Quan Lộc, Tài Bạch, and by Earthly Branch of Ty, Dan, Tuat. Writing by palace name suits readers, writing by Earthly Branch suits programming.
Why is no palace read alone?
The reason lies in how stars are placed: a star does not stay still in one spot but always relates to other palaces through Earthly Branch. The book Đẩu Số Tinh Thanh further distinguishes "phu cung": auspicious stars, whether occupying or shining, are both called phu cung; in the forward direction the earlier palace helping the later is called phu, in the reverse direction the later palace helping the earlier is called cung. So even the direction of support has its own name, showing the system of relations between palaces is built in some detail.
A palace read alone tells only which stars occupy it, not which stars converge, which oppose, which flank. With the same occupying star, if the Tam Hop is all auspicious the meaning differs sharply from when the Tam Hop holds inauspicious stars; if the opposite palace holds Hóa Kỵ then the home palace is affected too; if the two Giap palaces hold Kình Dương and Đà La then pressure rises. This is why the saying "no palace is read alone" becomes a foundational principle of Tử Vi Đẩu Số.
One further note: the ranking of strength between palace layers is where schools differ most, and no school is accepted as the common standard. Readers should know which convention a text follows before applying it.
