BaZi · Glossary
Yuan Yun (Period Luck) vs BaZi Luck Pillars — the Difference
Deep Oracle Editorial Team · 2026-07-27 · 1 min read
Yuan yun ("period luck") is the collective name for the time units of the Three Cycles Nine Periods system: twenty-year periods mapped to the nine Luoshu stars and trigrams, used in xuankong feng shui to describe the character of eras.
Yuan yun vs the BaZi luck pillars
The two are often confused and belong to different systems. Yuan yun is an environmental clock: fixed 20-year beats, identical for everyone, derived from the xuankong periodization. The BaZi luck pillar (dayun) is personal: computed from an individual's birth time and sex, changing every ten years, read against the natal chart's preferences. One is macro and shared, the other individual. This site keeps them separate: the BaZi engine computes four pillars, luck pillars and annual pillars, and does not feed yuan yun into any chart calculation.
Sources
The term belongs to the xuankong school and appears throughout Qing-era xuankong writing; it is not native to Ziping BaZi vocabulary.
Related terms
Three Cycles Nine Periods · Xuankong Flying Stars · Luck Pillars · Annual Pillars
In the classical texts
Passages in the classical texts held on this site where the term occurs, transcribed from the named edition. The texts do not necessarily use the term the way it is used today.
岁诸神煞之尊綂正方位廽送六气迁运四时以成岁功至尊无上若人遇尅冲压伏皆为不祥之兆运者恊和二十四气般运一生休咎扶持四柱辅弼三元运与流年二者相为表里乃人命祸福死生所系岁用天元运用地支凡行好运而日干伤流年天元为祸轻若行不好运及脱财官运而日干伤岁干为祸重若是巳发之命祸患立至凡行不好运未可便言衰绝大要知巳发未发
生月逆行昙莹曰干禄推之有向背吉防防之有浅深背而逆之者可定其贫向而顺之者以言其富然而不在一途取轨亦有逄背禄而不贫于是支作人元运防从而得失男迎女送否防交居防吉防防作用定矣
真歌云看命天元为主首先看克刑无与有支神还复是冲刑纳音有无相战鬬又云遇冲先破后须成唐沈芝云四冲对位封王格采真歌云命若无冲有元运只怕刑冲破命中刑冲若临相滋助定保珍材意气雄】合则少兮受寡助之力鬼则多兮招毁谤之端【五行合者合神有三一曰干合二曰六合三曰三合其用则一也相合相生主吉相合相伤主凶如甲巳乃中正之合乙庚
【天元一气定侯伯之迁荣，支作人元运商徒而得失】
文：阳居择地水龙同，不厌前篇议论重，但比阴基宜阔大，不争秀气喜粗雄，大江大河宜气厚，涓涓滴水也关风，若得乱流如织锦，不分元运也亨通。
盖主元运之说者。
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