Aggregate the whole suite wiki onto the Institution page

Wiki/Home.md is the suite's front door; every layer's wiki now mirrors here
under Wiki/<layer>/ (core, contraband, justice, gangs, ward), so the whole
suite reads in one place with the index linking to the local pages. The
layer repos stay canonical -- Tools/sync-wiki.sh refreshes the aggregated
copy on demand. The README's main page points to it.

Wiki/gangs/Joining.md

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+# Joining a gang
+
+*How Gangs decides who runs with a crew — and why a well-run colony keeps almost everyone out.*
+
+Membership is not random, and it is not a mood event. A pawn joins a gang only when their **disposition
+and their circumstances line up at once** — the same `Nature × Nurture` engine that drives every other
+behaviour in the Institution suite. This page covers the exact test, why the bar is set where it is,
+and how you keep pawns on the right side of it.
+
+## The rule
+
+```
+WouldJoin(pawn) == Propensity.Nature(pawn) * Propensity.Nurture(pawn) >= JoinThreshold
+JoinThreshold = 0.9
+```
+
+Two gates before the maths even runs:
+
+| Guard | Effect |
+|---|---|
+| `pawn == null` | never joins |
+| not `RaceProps.Humanlike` | never joins — animals and mechs are out |
+
+Then it is one line: multiply the pawn's **Nature** by their **Nurture** and compare to **0.9**. There
+is no dice roll here. `WouldJoin` is a deterministic threshold on the two propensity scores, so the
+same pawn in the same situation always gives the same answer — join, or don't. (This is different from
+Core's `Propensity.Would(...)`, which *is* a seeded random roll used for one-off acts like a piss
+spree. Gang membership is a standing condition, so it uses the raw product.)
+
+### The two halves
+
+Both terms come from **Institution: Core** — see Core's own documentation for the full tables — but you
+need the shape of them to understand the bar:
+
+- **Nature** (`0..1`) is *who the pawn is*: a base of `0.05`, plus trait weights, clamped to `[0, 1]`.
+  Psychopath `+0.45`, Bloodlust `+0.35`, Kleptomaniac `+0.40`, Greedy `+0.25`, Abrasive `+0.15`;
+  and it goes **down** for Kind `−0.30` or Ascetic `−0.15`. This is fixed at pawn creation and barely
+  moves.
+- **Nurture** (a multiplier, `~≥ 0.4`, base `1.0`) is *the situation you put them in*: a floored mood
+  multiplies it up hard (roughly `×2.5` under 0.20 mood, `×1.6` under 0.35), being held while
+  miserable adds more (`×1.4`), a hardened record (negative reform) raises it, and — critically —
+  **deterrence pulls it down** (`×Lerp(1.3, 0.7, deterrence)`, neutral `1.0` at baseline order, so a
+  high-deterrence colony scales nurture toward `0.7`). This is the half you control.
+
+## Why the bar is high
+
+`0.9` is a deliberately steep threshold. From the source, in its own words:
+
+> A high bar, on purpose: gangs are a symptom of a badly-run colony, not furniture. A healthy Rimworld
+> — content pawns, an orderly colony — grows few gangs, if any.
+
+Because the two terms are **multiplied**, both have to be substantial for the product to clear `0.9`.
+A nasty pawn in a happy, policed colony has a low nurture and stays out. A saintly pawn in a hellhole
+has a near-zero nature and stays out. You only get a gang when a genuinely disposed pawn is *also*
+neglected or unpoliced — foul streak **and** bad situation, together.
+
+That is the design speaking through the arithmetic: a gang is never bad luck. It is feedback.
+
+## Worked examples
+
+All numbers below use Core's documented factors; the intermediate nurture figures are rounded to show
+the shape of the decision.
+
+| Pawn | Nature | Situation → Nurture | Product | Joins? |
+|---|---|---|---|---|
+| **Kind colonist**, ordinary life | `0.05 − 0.30 → 0.00` (clamped) | content, `≈ 1.0` | `0.00` | **No** — nature floors it |
+| **Greedy prisoner**, content, policed | `0.30` | fed & high deterrence, `≈ 0.7` | `≈ 0.21` | **No** |
+| **Greedy prisoner**, starved & neglected | `0.30` | mood floored + held, `≈ 3.5` | `≈ 1.05` | **Yes** |
+| ...same pawn, but you raise deterrence | `0.30` | `× ≈ 0.7` → `≈ 2.45` | `≈ 0.74` | **No** — deterrence tipped them out |
+| **Psychopath + Bloodlust**, mood floored | `≈ 0.85` | mood floored + held, `≈ 3.5` | `≈ 2.9` | **Yes** — nothing short of reform pulls this back |
+
+The middle rows are the whole game of it. The **same greedy prisoner** joins or abstains purely on how
+you run the wing. The Kind colonist and the near-maxed psychopath are the fixed poles: one essentially
+cannot join, the other essentially always will if you neglect them. Everyone in between is a policy
+choice.
+
+The mod's own integration test asserts exactly these poles: a psychopath-plus-bloodlust pawn with a
+floored mood returns `WouldJoin == true`, and a Kind colonist in ordinary circumstance returns
+`WouldJoin == false`.
+
+## It works for every pawn, everywhere
+
+There is no "prisoners only" special case. The comment is explicit:
+
+> Any pawn — colonist, prisoner, slave — can, wherever they are.
+
+`WouldJoin` reads nothing about a pawn's secured status. A disposed **free colonist** can run with a
+crew on the outside; a **prisoner** can run with theirs on the inside; a **slave** likewise. This is
+what lets a gang span the wall — an outside member and an inside member of the same crew (see
+[Networks and Smuggling](Networks-and-Smuggling.md)). Being held raises nurture (misery), but it is not
+a requirement.
+
+## The cadence: the 5000-tick check
+
+Membership is re-evaluated on a fixed interval by the gang map component:
+
+```
+CheckInterval = 5000 ticks
+MapComponentTick: run only when TicksGame % 5000 == 0
+```
+
+**5000 ticks** is about **2 in-game hours** (a RimWorld day is 60,000 ticks), or roughly **80 seconds**
+of real time at normal (1×) speed. On each fire, the component:
+
+1. Gathers `crew` — every spawned humanlike on the map for whom `WouldJoin` is currently true.
+2. Pairs up unaffiliated members of `crew` who **share a room and a bond** into gangs (see
+   [Affiliations and Segregation](Affiliations-and-Segregation.md)).
+3. Runs one round of network resupply inside each gang (see
+   [Networks and Smuggling](Networks-and-Smuggling.md)).
+
+Because the check re-reads `WouldJoin` every time, membership is *live*: a pawn whose situation improves
+past the point where the product drops back under `0.9` simply stops being eligible to form new bonds.
+The bar is not a one-time gate at recruitment — it is a standing condition the colony is continuously
+graded against.
+
+## How to keep pawns out
+
+You do not fight the gang system. You lower nurture, which lowers the product, which drops pawns below
+`0.9`:
+
+- **Feed them and give them recreation.** Mood is the biggest nurture multiplier by far. A wing above
+  0.35 mood loses the `×2.5`/`×1.6` spikes entirely.
+- **Keep deterrence high** (Institution: Justice). Deterrence scales nurture down toward `0.7`; a
+  well-policed colony is *arithmetically* less gang-prone. This is the row in the table above where the
+  same greedy prisoner flips from *joins* to *abstains*.
+- **Reform, don't just punish.** A hardened record (negative reform) *raises* nurture; discipline that
+  actually reforms (positive reform) lowers it. Harsh punishment that prisonizes a pawn makes the
+  gang problem worse, not better.
+- **Accept the two poles.** A near-maxed psychopath will run with someone the moment you slip; a Kind
+  pawn essentially never will. Spend your attention on the middle.
+
+---
+*Part of the **Institution** suite — Core · Contraband · Justice · Gangs (this). Each mod stands alone; together they are one system.*
+*AI disclosure: developed with substantial assistance from Claude (Anthropic).*