用神
the favorable god — five ways to choose it
用神 yòng shén, "the useful god," is the single element (expressed as a 十神) the chart most needs — the direction a life bends toward ease when it shows up in a 大运 or 流年, and toward strain when it is missing or attacked. Selecting it correctly is the payoff of modules 9 and 10: strength tells you which direction the chart leans; pattern tells you what shape it has taken; 用神 tells you what to actually watch for in the moving decades and years (module 14).
The tradition does not have one method — it has (at least) five, and serious readers use the one that fits the chart in front of them, sometimes combining two. This module teaches all five as a decision procedure, not a single formula.
扶抑 — supporting or restraining — 扶抑
The default method, and the one module 9's strength judgment feeds directly. If the day master is weak (身弱), the favorable direction is 扶 fú — support: 印 (resource, generates the day master) or 比劫 (peer, shares the day master's element). If the day master is strong (身强), the favorable direction is 抑 yì — restraint: 官杀 (discipline/pressure, controls the day master), 食伤 (output, drains the day master), or 财 (wealth, the day master controls it and so is drained by controlling it).
Applied to the worked chart: 身弱 (module 9's verdict) → the favorable direction is 扶, support. The chart's own 正印格 (module 10) already names the specific support: 印 (here, 癸/子 water) is both the pattern's engine and the strength method's prescription. When pattern and strength method agree this cleanly, the 用神 call is unusually solid — 印 (水) is this chart's 用神 by 扶抑.
调候 — climate as the tiebreaker — 调候
Module 8 introduced 调候 as raw climate: winter charts want fire, summer charts want water. As a 用神 method, it is a specific claim — that for charts born deep in an extreme season (especially 子/丑 winter months or 午/未 summer months), the chart's most urgent need is temperature regulation, and this can OUTRANK the 扶抑 strength calculus. A winter-born 身强 chart that would classically want 抑 (restraint) may still need fire first, because a strong-but-freezing chart cannot function until it is warmed — 调候 supplies what 扶抑 alone would miss.
Applied to the worked chart: month branch 子 is deep winter — by 调候 alone, this chart wants 丙 (fire) urgently. The month stem IS 丙. This is not a coincidence worth over-reading (丙 was already required by the 五虎遁 rule from a 己 year, module 6) — but it does mean the chart's 调候 need happens to already be met by a stem present in the chart itself, which a trained reader would flag as a small strength in the chart's own construction, independent of the 扶抑 finding.
病药 — the illness and its medicine — 病药
A more surgical method: identify the chart's single most damaging element or structure (its "illness," 病) and let the 用神 be whatever directly cures it (its "medicine," 药). Where 扶抑 asks a general strength question, 病药 asks a specific diagnostic one — is there one 十神 so excessive or so damaging that fixing IT is the chart's actual priority, ahead of the general strength balance?
Classic 病药 cases: an over-strong 枭神 (module 7) smothering 食神 — the illness is the owl, the medicine is 财破印 (a 财 stem controlling the excess resource). An unchecked 七杀 attacking a weak day master — the illness is the unchecked pressure, the medicine is 食神 or 印 to control or absorb it. 病药 is most useful exactly when 扶抑's general prescription and the chart's worst structural problem point in different directions — then the illness/medicine read takes priority.
通关 — bridging a stuck conflict — 通关
When two elements in a chart sit in direct 克 (module 2's restraining cycle) with roughly equal strength — a stalemate, not a clear winner — the favorable god can be the element that BRIDGES them: the one the first generates and that in turn generates (or otherwise appeases) the second. This is 通关 tōng guān, "connecting the pass." A chart with strong 金 directly opposing strong 木 (metal felling wood) with neither side yielding might favor 水 — water the metal generates, which in turn nourishes the wood — turning a standoff into a flow.
通关 is the method to reach for when a chart reads as "stuck" rather than simply strong or weak — two roughly matched forces locked against each other, where more of either side just escalates the conflict instead of resolving it.
专旺 — when overwhelming force is nourished, not fought — 专旺
The formal name for what module 10's 从旺格 already described from the pattern side: when one element so thoroughly dominates a chart that there is no reasonable point of resistance, the favorable god STRENGTHENS the dominant element rather than opposing it — 比劫 and 印 (what shares and what generates the dominant force), never 官杀/财/食伤 (anything that would fight it). 专旺 is 从旺格's 用神 method: name the pattern with module 10, then apply 专旺's "join it, don't fight it" logic here.
choosing among the five — a decision order
In practice: start with 扶抑 (module 9's strength verdict) as the default frame. Check 调候 — if the chart is born in a climate extreme, does temperature outrank the 扶抑 call? Check 病药 — is there one specific illness so damaging it should take priority over the general balance? Check whether the chart is genuinely 从格/专旺 territory (module 10) before applying normal 扶抑 logic at all — a true 从格 case inverts everything. Reach for 通关 only when two forces read as genuinely locked, not merely present.
These are not five competing final answers — they are five lenses, and a mature reading often finds two or three of them agreeing (as the worked example did: 扶抑 and the chart's own 正印格 pattern both point to 印/水). When they disagree, that disagreement is itself the honest finding — note it, and hold the conclusion loosely, exactly as this whole project holds every conclusion: computed structure, human reading, never a verdict.