The Three Cosmic Boards: Qi Men, Tai Yi, and Da Liu Ren
5 min read·
Updated
The Three Cosmic Boards (三式 sān shì) are the three highest divination systems of the classical Chinese canon: Qi Men Dun Jia (奇门遁甲 qí mén dùn jiǎ), Tai Yi (太乙 tài yǐ), and Da Liu Ren (大六壬 dà liù rén). They are grouped together because each casts a moment onto a structured board and reads it by fixed rules, yet each answers a different kind of question. Understanding the Three Cosmic Boards as a set is the clearest way to see what Qi Men is for — and what it is not. This guide places Qi Men among its two siblings and explains how the three divide the labor.
What the Three Cosmic Boards are
“式” (shì) refers to a cosmological board — a device or diagram that models the sky, the earth, and the moment, then lets a practitioner read the arrangement. The tradition ranks Qi Men, Tai Yi, and Da Liu Ren as the three most sophisticated of these, historically studied together and often reserved for serious matters of strategy, state, and consequence.
What unites them is a shared discipline: the board is deterministic. Like Ba Zi (八字 bāzì) four pillars, each is computed from date, time, and solar term by fixed derivation rules, not improvised. The reader interprets a finished board; the board is never guessed at. What separates the three is scale and purpose — one reads terrain, one reads long cycles, and one answers a single sharp question.
八字 · Four Pillars
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Qi Men Dun Jia is the strategy and timing member of the Three Cosmic Boards. Its name translates roughly as “Mysterious Gates, Hiding the Jia,” and its board maps a moment onto the Nine Palaces (九宫 jiǔ gōng), a 3×3 grid laid out on the Luo Shu (洛书 luò shū) magic square. Onto that grid it stacks four layers: the Earth Plate (地盘 dì pán) of stems, the Heaven Plate (天盘 tiān pán) carrying the Nine Stars (九星 jiǔ xīng), the Eight Gates (八门 bā mén), and the Eight Deities (八神 bā shén).
Read together, those layers describe the ground around a decision: which direction favors a move, which hour supports it, and how the forces around a matter are arranged. Qi Men is closer to a commander studying a map than to a life-story reading, which is why the tradition ties it to military strategy. For the fuller picture of the system, see our plain guide to Qi Men Dun Jia. Of the three boards, Qi Men is the one most people encounter first today.
Tai Yi — the macro cycles
Tai Yi is the broad, cyclical member of the set. Where Qi Men zooms in on a single decision, Tai Yi works at the widest scale — long time cycles and matters of state. Historically it was the most rarefied of the Three Cosmic Boards, associated with imperial and astronomical use rather than everyday divination, and it is the least commonly practiced of the three in the modern English-speaking world.
Because it addresses macro patterns rather than a personal question or a specific move, Tai Yi sits at a different altitude from its siblings. A working practitioner reaches for it when the question is about large arcs, not when it is about which afternoon to sign a lease. We treat it here as context for the other two rather than as a system we cast.
Da Liu Ren — precise question divination
Da Liu Ren is the fine-grained question-and-event member. Where Qi Men reads terrain, Liu Ren answers a specific question cast at a moment: “what will happen with this matter.” Its board is built from two rings — a fixed Earth Plate (地盘) of the twelve Earthly Branches and a rotating Heaven Plate (天盘) aligned so that the Monthly General (月将 yuè jiàng), the sun’s position by solar term, sits over the hour branch.
From that alignment the practitioner derives the Twelve Heavenly Generals (十二天将 shí èr tiān jiàng), then the Four Lessons (四课 sì kè) and the Three Transmissions (三传 sān chuán). The Three Transmissions — initial, middle, and final — are read as a sequence: cause, development, and outcome. That timeline is what makes Liu Ren the most precise of the three for “when” and “what next.” It is a system we will cover in its own right; for now, note it as Qi Men’s more forensic sibling.
How the three divide the labor
Held side by side, the Three Cosmic Boards sort cleanly by scale. Tai Yi reads the long cycle. Qi Men reads the terrain for a move. Da Liu Ren reads a single question to its outcome. None of them is a destiny reading — that work belongs to Ba Zi, which maps the pillars you are born with rather than a moment you choose to act in.
This is exactly the distinction to keep in mind: Ba Zi describes the ground you stand on, while the Three Cosmic Boards read a chosen moment upon it. We draw that line out in Qi Men Dun Jia versus Ba Zi, and lay out the destiny side at our Ba Zi hub. If you are new to this work, start with the map you were born with: plot your four pillars free with the Ba Zi calculator, then read the strategy boards as the layer you add on top when a decision is at hand.
