TL;DR: Tiểu vận is the yearly fortune in Bát Tự (BaZi), one can chi per year, used to supplement the ten-year đại vận. According to Tam Mệnh Thông Hội, males start from Bính Dần and proceed forward, females start from Nhâm Thân and proceed in reverse, but the book also records the theory of Túy Tỉnh Tử that it starts from the birth hour. Tiểu vận is only one reference layer and does not replace đại vận and lưu niên.
What Is Minor Fortune in Bát Tự?
Minor fortune is the fortune calculated year by year, each year corresponding to one can-chi, used to supplement the ten-year major fortune in the Bát Tự system. The book Tam Mệnh Thông Hội by Vạn Dân Anh of the Ming dynasty says: "大运司十年之休咎，小运掌一岁之灾祥，是小运者补大运之不足而立名也"[1], meaning major fortune governs ten years of good and bad, minor fortune governs one year of fortune and misfortune, and minor fortune was established to fill the gaps of major fortune. This understanding positions minor fortune as a short operating layer, functioning to fill the gaps between the major shifts of major fortune.
Unlike major fortune, which starts from the birth month and moves through ten-year palaces, minor fortune moves year by year. Therefore, in practice, people often use minor fortune to examine odd years, especially the period before the first major fortune begins, when major fortune has not yet taken clear effect.
What Is the Method of Starting Minor Fortune for Males at Bính Dần and Females at Nhâm Thân?
The traditional method of starting minor fortune in Tam Mệnh Thông Hội states: "古人以男起丙寅顺行，女起壬申逆行，一定而不可易也"[1]. This means males start minor fortune from the Bính Dần pillar and go forward, females start from the Nhâm Thân pillar and go backward. This is a fixed convention, not changing per chart.
The explanation cited in the book: "解者谓男之阳火，元气起戊子，三十丁巳，十月至丙寅，此木生火；女之阴水，元气起庚子，二十辛巳，十月至壬申，为金生水，此其数也"[1]. In essence, males belong to yang fire, primordial qi starts from Mậu Tý, reaches Đinh Tỵ at thirty, and at the tenth month reaches Bính Dần, corresponding to wood generating fire; females belong to yin water, primordial qi starts from Canh Tý, reaches Tân Tỵ at twenty, and at the tenth month reaches Nhâm Thân, corresponding to metal generating water. This is the numerical explanation of the ancients, not an astronomical proof.
For example, a male born in the year Giáp Tý, the first year's minor fortune is Bính Dần, the next year is Đinh Mão, the year after is Mậu Thìn, and so on forward through the sixty can-chi cycle. A female also born in Giáp Tý, the first year's minor fortune is Nhâm Thân, the next year is Tân Mùi, the year after is Canh Ngọ, going backward through the can-chi cycle.
Is There Only One Way to Start Minor Fortune?
No. Tam Mệnh Thông Hội also records the view of Túy Tỉnh Tử (醉醒子): "醉醒子以为男女小运皆由时生而行之，逆顺亦以年定"[1]. In this view, minor fortune for both males and females starts from the birth hour pillar, and the forward or backward direction is likewise set by the birth year. The book gives an example: a person with a yang destiny, born in a yang year, with birth hour Giáp Tý, would at birth already run minor fortune Ất Sửu, at two years old run Bính Dần, one year per position, cycling back after the full cycle; a yin destiny born in a yang year goes backward in the same manner ("阴命阳年逆行亦然"). The book continues "尝试用之，屡验", meaning the method was tried and proved right many times, but it must still be weighed against major fortune, the useful god and the day master in the four pillars to judge good or bad.
Thus, the book records two views side by side: the old method of males Bính Dần, females Nhâm Thân; and the view of Túy Tỉnh Tử, following the birth hour and the forward or backward direction of the year. The book rejects neither, only saying the old method is "一定而不可易" and the latter view is "屡验". Learners should know which convention they follow and state it clearly when interpreting.
How Does Minor Fortune Differ from Major Fortune and Annual Fortune?
These three layers differ in time unit, starting method, and role in interpretation. The table below summarizes the differences.
| Criterion | Major Fortune | Minor Fortune | Annual Fortune |
|---|---|---|---|
| Time unit | One step per ten years | One step per year | One year, calculated by that year's can-chi |
| Starting method | From birth month, yang males and yin females count forward to the coming solar term, yin males and yang females count backward to the past solar term, three days converted to one year | Males start Bính Dần forward, females start Nhâm Thân backward (or by birth hour and year's forward/backward direction) | The can-chi of the year in question, no starting needed |
| Role | Governs ten years of good and bad, the larger context | Fills gaps of major fortune, examines each year | Governs one specific year, combined with major and minor fortune |
| When used | Throughout life, after major fortune begins | Used exclusively in childhood, before major fortune begins; afterwards weighed together with major fortune | Every year, when detailed examination is needed |
Tam Mệnh Thông Hội also emphasizes: "大运虽吉，其小运不通，未可便言吉利；大运虽凶，其小运却吉，未可便作凶推"[1]. This means if major fortune is good but minor fortune is not smooth, one cannot immediately say it is good; if major fortune is bad but minor fortune is good, one cannot hastily consider it bad. This shows minor fortune has its own weight, not merely dependent on major fortune.
Annual fortune is different. Annual fortune is the can-chi of the year in question, for example 2025 is Ất Tỵ, 2026 is Bính Ngọ. Annual fortune needs no starting, as it is a calendrical fact. Tam Mệnh Thông Hội has a chapter "论太岁" discussing thái tuế: the birth year pillar is called đương sinh thái tuế, and the year that turns each year is called du hành thái tuế, i.e., annual fortune; the chapter also names chân thái tuế, chinh thái tuế and tuế vận tịnh lâm[1]. The book likens thái tuế to the ruler and major fortune to the minister: when ruler and minister are in harmony the year is good, and when they meet punishment and conflict the year is bad ("太岁如君也，大运如臣也")[1].
What Is Minor Fortune Used for in Practice?
Period Before Major Fortune Begins
Children who have not yet started their first major fortune have no major fortune to examine. In the passage recording the view of Túy Tỉnh Tử, Tam Mệnh Thông Hội writes: "童限未交大运，专用此法"[1], meaning that for a child's years before major fortune begins, this method, that is, starting minor fortune from the birth hour, is used exclusively. This is where the book states most clearly when minor fortune is used.
Examining Odd Years Between Major Fortune Steps
Once major fortune has begun, each step lasts ten years. Within those ten years, some years have annual can-chi matching the favorable useful god, some match the unfavorable god. Minor fortune is used as an additional check layer, to see if that year has extra support or extra obstruction. The same passage says: "先详八字衰旺喜忌，然后以此参之，无不中矣"[1], meaning first examine carefully the strength and weakness, the favorable and unfavorable elements of the eight characters, then bring in this method as a reference.
Minor Fortune Entering the Palaces of Death, Extinction, or Strong Sát
Still in that passage, the book records: "行死绝煞旺之宫，必有危难"[1]. That is, when minor fortune enters the palace of death, extinction, or where sát is strong, the book holds that danger and hardship are certain. This is a warning within the framework of divination, not a statement about actual life.
Why Is Minor Fortune Used Less Than Major Fortune and Annual Fortune?
Tam Mệnh Thông Hội lamented: "今之谈命者只以大运为用，殊不知小运亦有紧关"[1]. Since the Ming dynasty, people have used only major fortune and ignored minor fortune. There are several possible reasons.
First, major fortune and annual fortune already form two layers sufficient for general interpretation. Adding minor fortune adds another layer, requiring the interpreter to track another can-chi sequence, easily leading to overlap and contradiction.
Second, the method of starting minor fortune is not unified. One school follows Bính Dần, Nhâm Thân; another follows the birth hour. When there are two starting methods for the same chart, interpretation results can differ, so many are reluctant to use it.
Third, minor fortune has no mechanism for starting by solar terms like major fortune. Major fortune is tied to the distance to solar terms, so it has specific time markers; minor fortune is just a fixed can-chi sequence, less tied to astronomy.
Points to Note When Using Minor Fortune
Minor fortune is a convention in the Bát Tự system, not a calendrical fact. Lunar dates, can-chi, solar terms are calculable facts and can be cross-checked with printed calendars; minor fortune is a way of arranging can-chi by the book's convention. Therefore, one should not present minor fortune as an objective truth, but clearly state it is the understanding of a school.
When interpreting, one should clearly state which convention is followed: males Bính Dần females Nhâm Thân, or starting from the birth hour. If not stated, readers may apply the method incorrectly.
Minor fortune should not be used independently to decide weighty matters in life. Tam Mệnh Thông Hội uses it as a reference layer, weighed together with major fortune, the useful god and the day master. Separating one layer to assert something exceeds the scope of the method itself.
Nhật Nguyệt's suggestion: if you want to try using minor fortune, choose a convention, state it clearly in the chart, and view it as an additional check layer alongside major fortune and annual fortune. Do not let a secondary layer overshadow the two main layers.
