Four Pillars glossary: stems, branches, ten gods and more

The Four Pillars (BaZi, or saju in Korean) uses a small, precise vocabulary. Here are 45 core terms, each with its hanja, pinyin, Korean reading, a plain English name and a one-line meaning, grouped the way you meet them when reading a chart.

How to use this glossary

The terms come in five groups: the building blocks (yin-yang and the five elements), the parts of a chart, the ten gods, the relations between branches, and the calendar and time terms that decide which characters a birth receives. The pinyin is given without tone marks, so two different words can look alike: 十神 (the ten gods as a whole) and 食神 (Eating God, one of them) are both written shishen.

Korean readings follow the usual Sino-Korean pronunciation, which is why 甲 is gap and 子 is ja. English names vary between books; the ones here match the names used in the haru app and in the other pages of this series.

Yin-yang and the five elements

Everything else rests on two ideas. Yin and yang split each sign into one of two polarities, and the five elements give it a kind of energy. The stems pair up by element - 甲 and 乙 are both Wood, 丙 and 丁 both Fire - with the first of each pair yang and the second yin. Two cycles connect the elements: one where each feeds the next and one where each restrains the element two steps on.

Building blocks: polarity, the five elements and their two cycles
Hanja	Pinyin	Korean	Plain English	Meaning
陰陽	yinyang	음양	Yin and yang	The two polarities; every stem and branch is one or the other
五行	wuxing	오행	Five elements	Wood, Fire, Earth, Metal, Water - the five phases used to describe balance
木	mu	목	Wood	Growth and spring; stems 甲乙, branches 寅卯
火	huo	화	Fire	Warmth and summer; stems 丙丁, branches 巳午
土	tu	토	Earth	Holding and the turn of seasons; stems 戊己, branches 辰戌丑未
金	jin	금	Metal	Firmness and autumn; stems 庚辛, branches 申酉
水	shui	수	Water	Flow and winter; stems 壬癸, branches 亥子
相生	xiangsheng	상생	Generation cycle	Each element feeds the next: Wood, Fire, Earth, Metal, Water, Wood
相剋	xiangke	상극	Control cycle	Each element restrains the one two steps on, e.g. Wood controls Earth

The parts of a chart

A chart has four pillars, and each pillar is one heavenly stem over one earthly branch, taken from the sixty cycle. The branches also hold hidden stems: 子, for instance, holds 壬 for 10 days and 癸 for 20 days of its thirty-day month, and the haru engine weights them by those days when it measures balance. The stem of the day pillar is the day master, the point from which the whole chart is read.

Parts of a chart: stems, branches, pillars and the day master
Hanja	Pinyin	Korean	Plain English	Meaning
天干	tiangan	천간	Heavenly stems	The 10 upper signs 甲 to 癸, each an element with yin or yang
地支	dizhi	지지	Earthly branches	The 12 lower signs 子 to 亥, tied to months, hours and animals
支藏干	zhicanggan	지장간	Hidden stems	Stems stored inside a branch by days, e.g. 子 = 壬 10 days, 癸 20 days
六十甲子	liushi jiazi	육십갑자	Sixty cycle	The 60 stem-branch pairs from 甲子 to 癸亥, used for years, months, days, hours
四柱	sizhu	사주	Four pillars	Year, month, day and hour of birth, each a stem over a branch
年柱	nianzhu	연주	Year pillar	Changes at lichun, not on 1 January
月柱	yuezhu	월주	Month pillar	Changes at each of the 12 jie terms
日柱	rizhu	일주	Day pillar	Read from the unbroken sixty-day count
時柱	shizhu	시주	Hour pillar	One of 12 double hours of two hours each
日干	rigan	일간	Day master	The stem of the day pillar; the centre every other character is read from

The ten gods

The ten gods are not spirits. They are ten labels for the relation between the day master and any other stem, found from two questions: how do the two elements relate (same, I produce, I control, controls me, produces me), and do the polarities match? Five relations times two polarities give ten names. For a 庚 (yang Metal) day master, for example, 辛 is Rob Wealth and 癸 is Hurting Officer.

The ten gods, each defined from the day master's point of view
Hanja	Pinyin	Korean	Plain English	Meaning
十神	shishen	십신	Ten gods	Ten names for how any stem relates to the day master
比肩	bijian	비견	Companion	Same element, same polarity as the day master
劫財	jiecai	겁재	Rob Wealth	Same element, opposite polarity
食神	shishen	식신	Eating God	Element the day master produces, same polarity
傷官	shangguan	상관	Hurting Officer	Element the day master produces, opposite polarity
偏財	piancai	편재	Indirect Wealth	Element the day master controls, same polarity
正財	zhengcai	정재	Direct Wealth	Element the day master controls, opposite polarity
偏官	pianguan	편관	Seven Killings	Element that controls the day master, same polarity (also called 七殺)
正官	zhengguan	정관	Direct Officer	Element that controls the day master, opposite polarity
偏印	pianyin	편인	Indirect Resource	Element that produces the day master, same polarity
正印	zhengyin	정인	Direct Resource	Element that produces the day master, opposite polarity

Harmonies, clashes and the useful element

Branches can combine or pull against each other. The tradition reads a harmony as two or three branches drawing together and a clash as two branches sitting opposite each other on the twelve-branch circle, six steps apart. Punishments describe a gentler kind of friction. The last two rows come from the balance step: whether the season (the month branch) supports the day master, and which element the chart is read as needing most. These are technical terms of the method, not forecasts.

Relations between branches and the balance terms used by the haru engine
Hanja	Pinyin	Korean	Plain English	Meaning
六合	liuhe	육합	Six harmonies	Six branch pairs that draw together: 子丑寅亥卯戌辰酉巳申午未
三合	sanhe	삼합	Three harmonies	Three branches that gather one element, e.g. 申子辰 = Water
半合	banhe	반합	Half harmony	Two of the three branches of a three-harmony set
沖	chong	충	Clash	Six opposite branch pairs: 子午丑未寅申卯酉辰戌巳亥
刑	xing	형	Punishment	Friction groups 寅巳申, 丑戌未 and the pair 子卯
自刑	zixing	자형	Self punishment	The same branch twice: 辰, 午, 酉 or 亥
得令	deling	득령	Season support	The month branch shares or produces the day master's element
用神	yongshen	용신	Useful element	The element a chart is read as most needing for balance

Calendar and time terms

The characters of a chart depend on exact moments. The 24 solar terms divide the sun's path into steps of 15 degrees; the 12 jie terms open the months and the 12 qi terms sit in their middle. The year pillar turns at lichun, which in 2026 came at 2026-02-04 05:02 Korean time, and the hour is read from true solar time - in Seoul in February that is 46 minutes behind the clock. The two rules at the end give the stems of the first month and the first hour.

Calendar and time terms that decide which characters a birth receives
Hanja	Pinyin	Korean	Plain English	Meaning
節氣	jieqi	절기	Solar terms	24 points of the sun's path, 15 degrees apart
節	jie	절	Jie term	The 12 terms that open a month, e.g. lichun at 315 degrees
中氣	zhongqi	중기	Qi (middle) term	The 12 terms in the middle of a month, e.g. the spring equinox at 0 degrees
立春	lichun	입춘	Start of Spring	Sun at 315 degrees; the year pillar turns here (2026-02-04 05:02 KST)
真太陽時	zhen taiyang shi	진태양시	True solar time	Clock time corrected for longitude and the equation of time
五虎遁	wuhudun	오호둔	Five-tiger rule	Finds the stem of the first (寅) month from the year stem
五鼠遁	wushudun	오서둔	Five-rat rule	Finds the stem of the 子 hour from the day stem

Questions

What is the difference between 十神 and 食神?

十神, the ten gods, is the whole set of ten relations. 食神, Eating God, is one member of that set: the element the day master produces, with the same polarity. Without tone marks both are written shishen.

Is 偏官 the same as 七殺?

Yes. Both names describe the element that controls the day master with the same polarity; haru's English label for it is Seven Killings.

Why are jie and qi terms kept apart?

Only the 12 jie terms change the month pillar. The 12 qi terms, such as the equinoxes and solstices, fall mid-month and do not change any pillar.

Does 用神 mean a lucky element?

No. The useful element is a balance term: the element the method reads as most helpful to even out a chart. It says nothing certain about events.