Zodiac Trines (San He) 三合
Sān Hé · Four groups of three signs that combine into a single element.
What it means
San He, "three harmony", groups the twelve branches into four trines of three, each spaced four positions apart. Shen, Zi and Chen form the Water frame; Hai, Mao and Wei the Wood frame; Yin, Wu and Xu the Fire frame; Si, You and Chou the Metal frame. The three positions are the birth, the peak and the storehouse of that element.
Why it matters
Trines are the strongest positive grouping in the compatibility tables and the most useful for describing working relationships rather than romantic ones — the tradition reads them as alliance, shared direction and cooperation. The same structure drives the Three Killings direction in feng shui and the storehouse logic that makes Chen, Xu, Chou and Wei behave differently from the other eight branches.
| Trine | Animals | Combines into |
|---|---|---|
| 申子辰 | Monkey, Rat, Dragon | Water 水 |
| 亥卯未 | Pig, Rabbit, Goat | Wood 木 |
| 寅午戌 | Tiger, Horse, Dog | Fire 火 |
| 巳酉丑 | Snake, Rooster, Ox | Metal 金 |
Where this site uses it
Trine membership is shown on every sign profile and is one of the relationships the compatibility calculator scores, with a weight just below Six Harmony. It also decides the Three Killings direction on the Tai Sui page, since that affliction sits in the sector opposite the year's own trine — which is why a single table drives both a compatibility score and a compass reading.