diff --git a/CMakeLists.txt b/CMakeLists.txt
index 927ac9a..3f925b7 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -96,6 +96,7 @@ if(WIN32)
                                 src/shim/hooks/tech_effects.cpp
                                 src/shim/hooks/compute_budget.cpp
                                 src/shim/hooks/colony_turn.cpp
+                                src/shim/hooks/system_output.cpp
                                 src/shim/hooks/fleet_movement.cpp
                                 src/shim/hooks/player_turn.cpp
                                 src/shim/hooks/tail_rng.cpp
diff --git a/docs/N-output-term.md b/docs/N-output-term.md
new file mode 100644
index 0000000..0b85144
--- /dev/null
+++ b/docs/N-output-term.md
@@ -0,0 +1,104 @@
+# N — the population → base-output term
+
+The formula that a colony's whole economy hangs off, and the one `src/app` names as its
+largest unmodelled input. It is now read from the instruction stream and compared against the
+running game.
+
+## What it is
+
+Output points are **linear in population**:
+
+```
+outputPerHead = populationTypeOutputModifier x 1.8 / 500000
+```
+
+`1.8` and `500000` are literals in the executable, and so are the imperial (`1.0`) and civilian
+(`0.33f`) type modifiers — the three-row population-type table is *built in code*, not loaded
+from the data files. Only the slave row's modifier comes from the data. An imperial population
+with no station therefore contributes exactly `3.6e-6` output points per head.
+
+A system's total output is a **sum of three independent terms**, not one multiplicative chain:
+
+```
+base = overHarvestDemand x speciesResourceOutputFactor
+     + (transitResources + availableResources) x stripMineFraction x 0.9
+     + imperialOutput + civilianOutput + slaveOutput
+
+total = addictionModifier x base
+      x playerOutMod x systemOutMod x setupOutputMult x rebOutMod x scOutMod
+```
+
+The station bonus multiplies **only** the imperial term; the morale modifier multiplies **only**
+the civilian term. The previous model in this module applied both to the whole thing, which is
+why `OutputModifiers` no longer carries `morale` or `stations` — they belong to
+`GroupOutputInputs`, one population row at a time.
+
+## API
+
+`src/game/sim/colony.h`:
+
+| function | what |
+|---|---|
+| `PopTypeOf(group, tuning)` | the population-type row: output/income modifiers and the row's population cap (imperial 50,000,000, civilian 20,000,000) |
+| `GroupOutput(GroupOutputInputs, tuning)` | one (group, species) row's contribution — the per-capita law |
+| `MoraleOutputMultiplier(morale, tuning)` | the civilian morale factor, with both of the original's guards |
+| `StripMineFraction(StripMineInputs)` | resource extraction efficiency |
+| `OverHarvestDemand(OverHarvestInputs)` | the strip-mining resource demand, which is also a summand of output |
+| `SystemBaseOutput(BaseOutputInputs, tuning)` | the three terms summed in the original's association |
+| `TotalSystemOutputRaw` / `TotalSystemOutput` | the multiplier tail, unrounded and rounded half-to-even |
+
+## Verified against the running game
+
+Two hooks in `src/shim/hooks/system_output.{h,cpp}`, both **compare** mode, config
+`src/shim/shim.cfg.output`:
+
+* `Game::ServerSystem::GroupOutput` — the per-capita law itself. **13,105 calls, 0 divergences**
+  across two species and two workloads.
+* `Game::ServerSystem::ComputeTotalOutput` — the whole sum and multiplier tail. **11,252 calls,
+  1 divergence**, and that one is a single ulp on one system, in a value the caller rounds to an
+  integer before using — so it cannot move any number the game stores. It is recorded, not fixed.
+
+Both functions were checked for stores to the game state before being chosen as compare
+targets, and each declares a Guard region over the whole system object: **0 undeclared writes in
+24,357 calls** turns that check from a claim into a measurement. The neighbouring
+`ComputeOutputFromRates` is deliberately *not* hooked — it repairs damaged ships in orbit.
+
+### Coverage — read this before quoting the zero
+
+24,357 calls is **13 distinct system states**. Unexercised, and therefore hypotheses:
+
+* the over-harvest branch (`SRoh` is 0 on every call in the corpus), including its `max(v, 1)`
+  floor;
+* the station factor (no system in the corpus has a station);
+* the slave term (no system in the corpus holds slaves);
+* both morale branches (every colony sits at 75, strictly between the two thresholds);
+* the addiction multiplier and the civilian capacity surplus.
+
+## `sim::Narrow`
+
+A 32-bit x87 build may leave an intermediate in a register at the register's own precision; the
+original's x87 runs with its precision-control field at 53 bits and rounds every multiply to
+double. The first live run made that visible as a one-ulp low result on **every** civilian row —
+4,957 divergences that were all the same defect, and none of them the model's. `sim::Narrow`
+forces the round the original performs anyway, and is a no-op on any SSE2 target.
+
+## Correction shipped alongside
+
+`ComputeBankruptcyLimits` used the decimal `-0.15` as the elimination-limit divisor. The image
+holds `-0.15000000596046448`, a widened float literal. The two disagree for **every** maximum
+income divisible by 3 — from `maxIncome = 3` upward — and for essentially every empire above
+about 3,000,000, which is six of the twenty-five bankruptcy records recoverable from the save
+corpus. Fixed, with `kBankruptcyInterestDivisor` named in the header and a test at the value
+where it first bites.
+
+## What this does and does not unblock
+
+It does **not** unblock `P01`. `ComputeBudget`'s missing input is a system's *money*, which runs
+this verified total through a second chain with its own population law (`incomeModifier / 14000`,
+no `1.8`) and its own multipliers. Checked against the bankruptcy-limit oracle over the whole
+save corpus, that composition reproduces **6 of 25 player-records exactly** — every record whose
+owner is the human player or an independent colony — and the single-system misses are short by a
+clean factor of 1.1, the AI trade/income difficulty multiplier, which is not on the wire.
+
+So the blocker has moved from the output term to the income tail. `src/app` is unchanged:
+5 leaves closed, 0 regressed, on both save pairs.
diff --git a/include/generated/sots_addresses.h b/include/generated/sots_addresses.h
index 780dc0d..b776e8f 100644
--- a/include/generated/sots_addresses.h
+++ b/include/generated/sots_addresses.h
@@ -1,5 +1,5 @@
 // GENERATED — do not edit. Facts about Sword of the Stars.exe (GOG 1.8.1).
-// Source: sots-re ghidra/addresses.json @ ab1c229, generated 2026-09-08 by tools/gen_addresses.py
+// Source: sots-re ghidra/addresses.json @ 58e3d85, generated 2026-09-08 by tools/gen_addresses.py
 // Runtime address = (uintptr_t)GetModuleHandle(NULL) + RVA (the exe is ASLR-relocated).
 #pragma once
 #include <cstdint>
diff --git a/src/game/sim/colony.cpp b/src/game/sim/colony.cpp
index 9048e06..1eb0599 100644
--- a/src/game/sim/colony.cpp
+++ b/src/game/sim/colony.cpp
@@ -234,21 +234,147 @@ OutputRates NormaliseOutputRates(const OutputRates& raw, bool suitAtIdeal, bool
     return r;
 }
 
+PopTypeConstants PopTypeOf(PopGroup g, const TuningTable& t) {
+    // The three rows are built in code from x87 literals; only the slave row reads the
+    // data files. `SLAVES_OUTPUT_MOD` / `SLAVES_INCOME_MOD` are not yet fields of
+    // TuningTable, so the slave row's modifiers arrive as zero until a loader supplies
+    // them -- which is the honest state, not a silent 1.0.
+    switch (g) {
+        case PopGroup::Imperial:
+            return PopTypeConstants{1.0, 1.0, 50000000};
+        case PopGroup::Civilian:
+            // 0.33 is a float literal in the image, so it widens to 0.33000001311302185.
+            return PopTypeConstants{F32(0.33), F32(0.33), 20000000};
+        case PopGroup::Slaves:
+            return PopTypeConstants{t.SLAVES_OUTPUT_MOD, t.SLAVES_INCOME_MOD, 0};
+    }
+    return PopTypeConstants{};
+}
+
 double MoraleOutputMultiplier(int morale, const TuningTable& t) {
-    if (morale >= t.MORALE_INCREASE_OUTPUT) return t.MORALE_INCREASE_OUTPUT_MOD;
-    if (morale <= t.MORALE_DECREASE_OUTPUT) return t.MORALE_DECREASE_OUTPUT_MOD;
+    // An entry of exactly zero means "no morale record for this species": the original
+    // returns 1 without consulting the thresholds.
+    if (morale == 0) return 1.0;
+    if (morale >= t.MORALE_INCREASE_OUTPUT) {
+        // The modifier is used only when strictly positive; otherwise the multiplier is 1.
+        return t.MORALE_INCREASE_OUTPUT_MOD > 0.0 ? t.MORALE_INCREASE_OUTPUT_MOD : 1.0;
+    }
+    if (morale <= t.MORALE_DECREASE_OUTPUT) {
+        return t.MORALE_DECREASE_OUTPUT_MOD > 0.0 ? t.MORALE_DECREASE_OUTPUT_MOD : 1.0;
+    }
     return 1.0;
 }
 
-double TotalSystemOutput(const OutputModifiers& m, const TuningTable& t) {
+double GroupOutput(const GroupOutputInputs& in, const TuningTable& t) {
+    const double count = static_cast<double>(in.count);
+    if (!(count > 0.0)) return 0.0;
+
+    const double q = count / kOutputPopulationDivisor;
+
+    double stationFactor = 1.0;
+    if (in.owned && in.group == PopGroup::Imperial) {
+        const double b =
+            t.STATION_BONUS_IMPERIAL_OUTPUT > 0.0 ? t.STATION_BONUS_IMPERIAL_OUTPUT : 0.0;
+        stationFactor = 1.0 + static_cast<double>(in.stations) * b;
+    }
+
+    double morale = 1.0;
+    if (in.group == PopGroup::Civilian && in.owned && !in.independent) {
+        morale = MoraleOutputMultiplier(in.morale, t);
+    }
+
+    // The original's association, and each step rounded to double the way its x87 does.
+    const double sf18 = Narrow(stationFactor * kOutputPopulationFactor);
+    const double a = Narrow(PopTypeOf(in.group, t).outputMod * sf18);
+    const double b = Narrow(a * morale);
+    const double v = Narrow(b * q);
+    return v > 0.0 ? v : 0.0;
+}
+
+float StripMineFraction(const StripMineInputs& in) {
+    const double fi = F32(static_cast<double>(in.infraBonus) + static_cast<double>(in.infra));
+    const double pop = static_cast<double>(in.population) / 100.0;
+    // The original's helper is an odd-symmetric cube root: pow(|x|, 1/3) with the sign
+    // carried through, using the double 1/3 rather than std::cbrt.
+    const double root = pop >= 0.0 ? std::pow(pop, 1.0 / 3.0) : -std::pow(-pop, 1.0 / 3.0);
+    double r = Clamp01(root * 0.01);
+    if (0.0001 + r >= 1.0) r = fi;
+    return static_cast<float>(r < fi ? r : fi);
+}
+
+double OverHarvestDemand(const OverHarvestInputs& in) {
+    const double avail = static_cast<double>(in.resourcesAvailable);
+    double b = 0.0;
+    if (in.overHarvestRate > 0.0) {
+        // The population sum is an int32 add in the original and the product is formed as
+        // rate x available x scale, in that order.
+        const double scale = Clamp01(static_cast<double>(in.population) * 1e-05);
+        const double v = in.overHarvestRate * avail * scale;
+        b = v > 1.0 ? v : 1.0;
+    }
+    const double base = in.owned ? static_cast<double>(in.speciesBaseDemand) : 0.0;
+    const double t = base + b;
+    const double lo = t > 0.0 ? t : 0.0;
+    return avail < lo ? avail : lo;
+}
+
+double SystemBaseOutput(const BaseOutputInputs& in, const TuningTable& t) {
+    OverHarvestInputs oh;
+    oh.overHarvestRate = in.overHarvestRate;
+    oh.resourcesAvailable = in.resourcesAvailable;
+    oh.population = in.imperialPopulation;
+    oh.speciesBaseDemand = in.speciesBaseDemand;
+    const double harvestTerm = Narrow(OverHarvestDemand(oh) * F32(in.speciesResourceOutput));
+
+    StripMineInputs sm;
+    sm.population = in.imperialPopulation;
+    sm.infra = in.infra;
+    sm.infraBonus = in.infraBonus;
+    const double resourceTerm =
+        Narrow(Narrow(static_cast<double>(in.transitResources + in.resourcesAvailable) *
+                      static_cast<double>(StripMineFraction(sm))) *
+               0.9);
+
+    GroupOutputInputs g;
+    g.stations = in.stations;
+    g.independent = in.independent;
+
+    g.group = PopGroup::Imperial;
+    g.count = in.imperialPopulation;
+    g.morale = in.imperialMorale;
+    const double imperial = GroupOutput(g, t);
+
+    g.group = PopGroup::Civilian;
+    g.count = in.civilianPopulation;
+    g.morale = in.civilianMorale;
+    const double civilian = GroupOutput(g, t);
+
+    g.group = PopGroup::Slaves;
+    g.count = in.slavePopulation;
+    g.morale = 0;
+    const double slaves = GroupOutput(g, t);
+
+    // The original's association: ((slaves + (civilian + (imperial + 0.0))) + (harvest + resource)).
+    const double popTerm = Narrow(slaves + Narrow(civilian + Narrow(imperial + 0.0)));
+    return Narrow(popTerm + Narrow(harvestTerm + resourceTerm));
+}
+
+double TotalSystemOutputRaw(const OutputModifiers& m, const TuningTable& t) {
+    if (!m.owned || m.rebelling) return 0.0;
+    const double addiction = m.addictionPhase3 ? t.ADDICTION_OUTPUT_MOD : 1.0;
     double v = m.baseOutput;
-    v *= MoraleOutputMultiplier(m.morale, t);
-    v *= 1.0 + t.STATION_BONUS_IMPERIAL_OUTPUT * m.stations;
-    if (m.addictionPhase3) v *= t.ADDICTION_OUTPUT_MOD;
-    v *= m.scOutMod * m.rebOutMod * m.techOutMod * m.systemOutMod * m.playerOutMod;
+    v = Narrow(v * m.playerOutMod);
+    v = Narrow(v * m.systemOutMod);
+    v = Narrow(v * m.techOutMod);
+    v = Narrow(v * m.rebOutMod);
+    v = Narrow(v * m.scOutMod);
+    return Narrow(addiction * v);
+}
+
+double TotalSystemOutput(const OutputModifiers& m, const TuningTable& t) {
     // Rounded half-to-even and kept as a double: the channel splits multiply this value,
     // and only the reported slot 0 truncates it to an int.
-    return RoundHalfEven(v);
+    return RoundHalfEven(TotalSystemOutputRaw(m, t));
 }
 
 OutputSplit SplitOutput(double total, const OutputRates& rates) {
diff --git a/src/game/sim/colony.h b/src/game/sim/colony.h
index 8575f5f..46904f2 100644
--- a/src/game/sim/colony.h
+++ b/src/game/sim/colony.h
@@ -263,30 +263,142 @@ constexpr double kOutputRateThreshold = 9.999999747378752e-05;
 // argument's default and the float32 accumulation.
 OutputRates NormaliseOutputRates(const OutputRates& raw, bool suitAtIdeal, bool infraFull);
 
-struct OutputModifiers {
-    double baseOutput = 0;             // population-derived base (its own formula is unresolved)
-    int morale = 0;
-    int stations = 0;                  // stations at the system
-    bool addictionPhase3 = false;
-    double scOutMod = 1.0;             // ScOutMod
-    double rebOutMod = 1.0;            // RebOutMod
-    double techOutMod = 1.0;           // tech-effect output multiplier
-    double systemOutMod = 1.0;         // sys.OutMod
-    double playerOutMod = 1.0;         // OutMod
+// ---------------------------------------------------------------------------------------
+// Base output: the population, resource and over-harvest terms
+//
+// LANE N CORRECTION (2026-09-08). The previous model here treated the whole of a system's
+// output as one multiplicative chain, `base x morale x stationFactor x ...`, with `baseOutput`
+// an unresolved input. That is the wrong shape. The original sums **three independent terms**
+// and applies morale and the station bonus to only some of them; the five player/system
+// multipliers at the end are the only genuinely global factors.
+//
+// The population term itself is linear and is carried entirely by the executable: output
+// points per head are `typeOutputMod x 1.8 / 500000`. See
+// sots-re findings/subsystems/output-term.md.
+// ---------------------------------------------------------------------------------------
+
+// The per-population-type constants. The original builds this three-row table **in code**
+// from x87 literals; only the slave row reads the data files. CONFIDENCE: high (read out of
+// the initialiser, including its x87 register rotation).
+struct PopTypeConstants {
+    double outputMod = 0;                   // multiplies the per-capita output rate
+    double incomeMod = 0;                   // multiplies the per-capita income rate
+    std::int64_t maxPopulation = 0;         // the row's population cap
 };
 
-// Morale effect on output: above the increase threshold x INCREASE_MOD, at or below the
-// decrease threshold x DECREASE_MOD, otherwise x1. CONFIDENCE: high.
+// Slave-row values come from the data files, so they are taken from the tuning table.
+PopTypeConstants PopTypeOf(PopGroup g, const TuningTable& t);
+
+// Output points contributed per head, before the type modifier: `1.8 / 500000`. Both are
+// .rdata literals, i.e. facts about the algorithm rather than about the shipped data.
+constexpr double kOutputPopulationFactor = 1.7999999999999998;  // the image's (double)1.8
+constexpr double kOutputPopulationDivisor = 500000.0;
+
+struct GroupOutputInputs {
+    PopGroup group = PopGroup::Imperial;
+    std::int64_t count = 0;      // heads in this group (imperial: Pop + pbon)
+    int morale = 0;              // the system's Morale int[7] entry for this species
+    int stations = 0;            // stations at the system
+    bool owned = true;           // the system has an owner
+    bool independent = false;    // sys.indi != null: morale is bypassed
+};
+
+// One (group, species) row's contribution:
+//   count <= 0                        -> 0
+//   q  = count / 500000
+//   sf = 1 + stations x STATION_BONUS_IMPERIAL_OUTPUT, imperial groups of an owned system only
+//        (and only while the constant is > 0)
+//   mo = morale multiplier, civilian groups only
+//   max(0, typeOutputMod x (sf x 1.8) x mo x q)
+// CONFIDENCE: high -- read instruction by instruction, including the association of the
+// multiplies, which is not free in 80-bit x87.
+double GroupOutput(const GroupOutputInputs& in, const TuningTable& t);
+
+// Morale effect on output. A morale entry of exactly 0 means "no record", and the original
+// returns 1 rather than consulting the thresholds; each modifier is also ignored unless it
+// is strictly positive, which matters because an unloaded tuning table has them at 0.
+// CONFIDENCE: high (both guards read from the branch).
 double MoraleOutputMultiplier(int morale, const TuningTable& t);
 
-// total = roundHalfEven(base x morale x (1 + STATION_BONUS_IMPERIAL_OUTPUT x stations)
-//                       x addiction x ScOutMod x RebOutMod x techOut x sys.OutMod x OutMod)
-// B4 correction: the engine's "round" is `fistp`/`fild` -- round to nearest, ties to EVEN --
-// and the result stays a double that the channel splits multiply; only the reported total
-// slot truncates it. CONFIDENCE: high on the multiplier chain and the rounding mode; the
-// base-output-from-population term is an input because its own formula is not resolved.
+// Resource extraction efficiency: `min( clamp01(cbrt((Pop + pbon)/100) x 0.01), Infra + ibon )`,
+// narrowed to float32 on the way in and on the way out. The `>= 1 - 1e-4` branch substitutes
+// the infrastructure term outright. CONFIDENCE: high.
+struct StripMineInputs {
+    std::int64_t population = 0;   // Pop + pbon
+    float infra = 0;               // Infra
+    float infraBonus = 0;          // ibon
+};
+float StripMineFraction(const StripMineInputs& in);
+
+// The over-harvest resource demand (0x007483b0). Also the term the resource ledger charges
+// against the stock, and -- multiplied by the species' resource-output factor -- one of the
+// three summands of a system's output.
+//   B = overHarvestRate > 0 ? max(rate x resourcesAvailable x clamp01((Pop+pbon) x 1e-5), 1) : 0
+//   return min(resourcesAvailable, max(speciesBaseDemand + B, 0))
+// CONFIDENCE: high on the structure; the `max(.., 1)` floor is UNVERIFIED behaviourally
+// because every save in the corpus carries SRoh = 0.
+struct OverHarvestInputs {
+    double overHarvestRate = 0;       // the normalised SRoh slider
+    std::int64_t resourcesAvailable = 0;  // Res, plus MRes + ARes2 when the owner strip-mines
+    std::int64_t population = 0;      // Pop + pbon
+    int speciesBaseDemand = 0;        // SpeciesDef +0x4c, from the data files
+    bool owned = true;
+};
+double OverHarvestDemand(const OverHarvestInputs& in);
+
+struct BaseOutputInputs {
+    // population
+    std::int64_t imperialPopulation = 0;      // Pop + pbon, owner species only
+    std::int64_t civilianPopulation = 0;      // Pop2 + pbon2 of the owner species, incl. surplus
+    std::int64_t slavePopulation = 0;         // summed over species
+    int imperialMorale = 0;                   // unused: imperial output ignores morale
+    int civilianMorale = 0;
+    int stations = 0;
+    bool independent = false;
+    // resources
+    std::int64_t transitResources = 0;        // TRes
+    std::int64_t resourcesAvailable = 0;      // Res (+ MRes + ARes2 when strip-mining)
+    float infra = 0;
+    float infraBonus = 0;
+    // over-harvest
+    double overHarvestRate = 0;               // SRoh
+    int speciesBaseDemand = 0;                // SpeciesDef +0x4c
+    double speciesResourceOutput = 0;         // SpeciesDef +0x50 (a float, widened)
+};
+
+// The sum of the three terms, before the global multipliers:
+//   overHarvestDemand x speciesResourceOutput
+// + (TRes + resourcesAvailable) x stripMineFraction x 0.9
+// + imperial + civilian + slave population output
+// CONFIDENCE: high on the terms; the summation order below reproduces the original's,
+// which matters because x87 addition is not associative.
+double SystemBaseOutput(const BaseOutputInputs& in, const TuningTable& t);
+
+struct OutputModifiers {
+    double baseOutput = 0;             // SystemBaseOutput
+    bool addictionPhase3 = false;
+    double scOutMod = 1.0;             // ScOutMod    (player +0x12c)
+    double rebOutMod = 1.0;            // RebOutMod   (player +0x128)
+    double techOutMod = 1.0;           // the game-setup output multiplier (player +0x224)
+    double systemOutMod = 1.0;         // sys.OutMod  (+0x7c)
+    double playerOutMod = 1.0;         // OutMod      (player +0x124)
+    bool owned = true;                 // no owner -> 0
+    bool rebelling = false;            // rbfl != 0 -> 0
+};
+
+// total = roundHalfEven( addiction x base x OutMod x sys.OutMod x techOut x RebOutMod x ScOutMod )
+// The five multipliers are applied in exactly that order in one uninterrupted 80-bit chain.
+// B4 correction retained: the engine's "round" is `fistp`/`fild` -- round to nearest, ties to
+// EVEN -- and the result stays a double that the channel splits multiply; only the reported
+// total slot truncates it.
+// CONFIDENCE: high. Note the return of the original is the *unrounded* double; the rounding
+// is done by its caller before the channel split, and is folded in here because every caller
+// in the game does it.
 double TotalSystemOutput(const OutputModifiers& m, const TuningTable& t);
 
+// The unrounded value the original returns, for a hook that compares its return bit for bit.
+double TotalSystemOutputRaw(const OutputModifiers& m, const TuningTable& t);
+
 struct OutputSplit {
     double trade = 0;
     double construction = 0;
diff --git a/src/game/sim/economy.cpp b/src/game/sim/economy.cpp
index 99f1891..4c791f4 100644
--- a/src/game/sim/economy.cpp
+++ b/src/game/sim/economy.cpp
@@ -162,7 +162,18 @@ BankruptcyLimits ComputeBankruptcyLimits(int maxIncome, const TuningTable& t) {
     constexpr int kTreasuryLimit = 2000000000;
     BankruptcyLimits l;
     // Elimination: the debt whose 15 %/turn interest equals the maximum income.
-    l.eliminationFloor = std::max(Ftol(static_cast<double>(maxIncome) / -0.15), -kTreasuryLimit);
+    //
+    // The divisor is NOT the decimal -0.15. The image's .rdata double is
+    // -0.15000000596046448, i.e. (double)(float)-0.15f -- the compiler widened a float
+    // literal once, at compile time. Lane K read it; lane N is fixing it here because the
+    // difference is not the "one ulp on large empires" the old note claimed. The two
+    // constants give a DIFFERENT truncated result for every maxIncome divisible by 3,
+    // starting at maxIncome = 3 (-20 against -19), and the disagreement rate rises with
+    // empire size to 100 % above about 3,000,000. Six of the twenty-five bankruptcy records
+    // recoverable from the save corpus would come out wrong with the decimal.
+    l.eliminationFloor =
+        std::max(Ftol(static_cast<double>(maxIncome) / kBankruptcyInterestDivisor),
+                 -kTreasuryLimit);
     // Protection: the tuned factor times the maximum income, never below the floor.
     l.protectionLimit = std::max(-Ftol(t.BANKRUPTCY_PROTECTION_LIMIT_FACTOR * static_cast<double>(maxIncome)),
                                  l.eliminationFloor);
diff --git a/src/game/sim/economy.h b/src/game/sim/economy.h
index 85ae86c..e0c0899 100644
--- a/src/game/sim/economy.h
+++ b/src/game/sim/economy.h
@@ -160,13 +160,18 @@ int TradeRouteIncome(const TradeRouteState& route, bool asOwner, double difficul
 // Bankruptcy
 // ---------------------------------------------------------------------------------------
 
+// The elimination limit's divisor, as the image holds it: a widened float literal, not the
+// decimal -0.15. Writing -0.15 changes the truncated result for every maxIncome divisible
+// by 3 and for essentially every empire above ~3,000,000 maximum income.
+constexpr double kBankruptcyInterestDivisor = -0.15000000596046448;
+
 struct BankruptcyLimits {
     int eliminationFloor = 0;   // BnkEl: below this the player is on the elimination clock
     int protectionLimit = 0;    // BnkPr: below this cost-cutting starts
 };
 
 // Limits from the sum of every owned system's maximum money output:
-//   eliminationFloor = max(ftol(maxIncome / -0.15), -2e9)
+//   eliminationFloor = max(ftol(maxIncome / kBankruptcyInterestDivisor), -2e9)
 //                      (the debt at which 15 %/turn interest eats the whole maximum income)
 //   protectionLimit  = max(-ftol(BANKRUPTCY_PROTECTION_LIMIT_FACTOR x maxIncome), eliminationFloor)
 // The limits a turn's check uses are the ones computed at the end of the previous turn
diff --git a/src/game/sim/numeric.h b/src/game/sim/numeric.h
index 6e292b3..6b4aa71 100644
--- a/src/game/sim/numeric.h
+++ b/src/game/sim/numeric.h
@@ -47,6 +47,28 @@ inline double Clamp01(double v) { return v < 0 ? 0 : (v > 1 ? 1 : v); }
 // field rounds to single precision; a formula that skips that step drifts.
 inline double F32(double v) { return static_cast<double>(static_cast<float>(v)); }
 
+// Force an intermediate back to IEEE double.
+//
+// The original runs its x87 with the precision-control field at 53 bits (measured: the
+// control word inside a hooked call is 0x127f), so every one of its multiplies rounds to
+// double. A 32-bit build of this module compiled for the x87 does NOT: the compiler is
+// allowed to leave intermediates in a register at the register's own precision, and the
+// result differs from the original in the last bit. Storing through a volatile forces the
+// round that the original performs anyway.
+//
+// It is a no-op wherever doubles are already evaluated at their own precision (any SSE2
+// target, so every 64-bit build and the host tests), which is why it costs nothing there.
+// Measured on the live game: without it, the civilian population term of a colony's output
+// came out one ulp low on every call; with it, the whole chain matches bit for bit.
+inline double Narrow(double v) {
+#if (defined(__i386__) || defined(_M_IX86)) && !defined(__SSE2_MATH__)
+    volatile double t = v;
+    return t;
+#else
+    return v;
+#endif
+}
+
 // A float32 literal as the image holds it. The compiler widened these decimals once, at
 // compile time, so `0.02` in the disassembly is really 0.019999999552965164; using the exact
 // decimal rounds differently at a truncation or comparison boundary.
diff --git a/src/game/sim/tuning.h b/src/game/sim/tuning.h
index e286b50..a1265ca 100644
--- a/src/game/sim/tuning.h
+++ b/src/game/sim/tuning.h
@@ -43,6 +43,12 @@ struct TuningTable {
     double SLAVES_DEATH_RATE_BYOUTPUT = 0;
     std::int64_t SLAVES_MIN_DEATHS = 0;
     std::int64_t SLAVES_MAX_DEATHS = -1;   // -1 = no upper clamp
+    // The slave row of the per-population-type table. The imperial and civilian rows of
+    // that table are built from literals inside the executable; only these three are read
+    // from the data files, through the loader's pointer slots.
+    double SLAVES_OUTPUT_MOD = 0;
+    double SLAVES_INCOME_MOD = 0;
+    double SLAVES_REPAIR_MOD = 0;
 
     // ---- system bonus (long-held stable colonies) ----
     int    SYSTEMBONUS_MINTURNS = 0;
diff --git a/src/shim/hooks/system_output.cpp b/src/shim/hooks/system_output.cpp
new file mode 100644
index 0000000..ab57e1f
--- /dev/null
+++ b/src/shim/hooks/system_output.cpp
@@ -0,0 +1,416 @@
+#include "shim/hooks/system_output.h"
+
+#include <cstdarg>
+#include <cstdio>
+#include <cstring>
+
+#if defined(_WIN32)
+#define WIN32_LEAN_AND_MEAN
+#include <windows.h>
+#endif
+
+#include "game/sim/colony.h"
+#include "game/sim/numeric.h"
+#include "generated/sots_addresses.h"
+
+namespace shim::hooks {
+
+using trace::Tv;
+namespace tv = trace::tv;
+namespace A = sots::addr;
+
+namespace {
+
+constexpr std::size_t kSystemGuardSize = 0x2d8;   // the whole ServerSystem object
+constexpr std::size_t kPopGroupStride = 0x18;     // {?, int type @+4, int species @+8, int64 @+0x10}
+constexpr std::size_t kMaxPopGroups = 4096;
+constexpr int kSpeciesSlots = 7;
+
+struct Env {
+    std::uintptr_t exe_base = 0;
+    void (*log_line)(const char*) = nullptr;
+};
+Env g_env;
+
+bool readable(const void* p, std::size_t n) {
+    if (!p) return false;
+    if (n == 0) return true;
+#if defined(_WIN32)
+    const char* c = static_cast<const char*>(p);
+    const char* const end = c + n;
+    while (c < end) {
+        MEMORY_BASIC_INFORMATION mbi;
+        if (!VirtualQuery(c, &mbi, sizeof mbi)) return false;
+        if (mbi.State != MEM_COMMIT) return false;
+        if (mbi.Protect & (PAGE_NOACCESS | PAGE_GUARD)) return false;
+        const DWORD ok = PAGE_READONLY | PAGE_READWRITE | PAGE_WRITECOPY | PAGE_EXECUTE_READ |
+                         PAGE_EXECUTE_READWRITE | PAGE_EXECUTE_WRITECOPY;
+        if (!(mbi.Protect & ok)) return false;
+        c = static_cast<const char*>(mbi.BaseAddress) + mbi.RegionSize;
+    }
+    return true;
+#else
+    return true;
+#endif
+}
+
+template <class T>
+T peek(const void* base, std::size_t off) {
+    T v{};
+    std::memcpy(&v, static_cast<const char*>(base) + off, sizeof v);
+    return v;
+}
+void* ptr_at(const void* base, std::size_t off) { return peek<void*>(base, off); }
+
+// A GlobalConst is reached through a pointer slot in .data holding the address of the storage
+// word the data-file loader fills.
+template <class T>
+T global_const_via_slot(std::uintptr_t slot_rva, T fallback) {
+    if (!g_env.exe_base) return fallback;
+    void** slot = reinterpret_cast<void**>(g_env.exe_base + slot_rva);
+    if (!readable(slot, sizeof(void*))) return fallback;
+    void* storage = *slot;
+    if (!readable(storage, sizeof(T))) return fallback;
+    T v{};
+    std::memcpy(&v, storage, sizeof v);
+    return v;
+}
+
+// ... and a few are reached by their storage address directly.
+template <class T>
+T global_const_at(std::uintptr_t rva, T fallback) {
+    if (!g_env.exe_base) return fallback;
+    const void* p = reinterpret_cast<const void*>(g_env.exe_base + rva);
+    if (!readable(p, sizeof(T))) return fallback;
+    T v{};
+    std::memcpy(&v, p, sizeof v);
+    return v;
+}
+
+std::int64_t population_of(const void* pop, int groupType, int species) {
+    if (!readable(pop, 0xc)) return 0;
+    const char* begin = static_cast<const char*>(ptr_at(pop, 0x4));
+    const char* end = static_cast<const char*>(ptr_at(pop, 0x8));
+    if (!begin || !end || end < begin) return 0;
+    const std::size_t n = static_cast<std::size_t>(end - begin) / kPopGroupStride;
+    if (n > kMaxPopGroups || !readable(begin, n * kPopGroupStride)) return 0;
+    std::int64_t sum = 0;
+    for (std::size_t i = 0; i < n; ++i) {
+        const char* e = begin + i * kPopGroupStride;
+        if (peek<std::int32_t>(e, 0x4) != groupType) continue;
+        if (peek<std::int32_t>(e, 0x8) != species) continue;
+        sum += peek<std::int64_t>(e, 0x10);
+    }
+    return sum;
+}
+
+// ---- the tuning values these two formulas read out of the running process ----------------
+//
+// Every one of them is logged with every record, so a divergence can always be attributed to
+// a value rather than to a guess about it.
+struct OutputTuning {
+    float stationBonusImperialOutput = 0;
+    std::int32_t moraleIncreaseOutput = 0;
+    float moraleIncreaseOutputMod = 0;
+    std::int32_t moraleDecreaseOutput = 0;
+    float moraleDecreaseOutputMod = 0;
+    float slavesOutputMod = 0;
+    // The population-type table the executable builds in code -- read live so the run either
+    // confirms the initialiser reading or refutes it.
+    float popTypeOut[3] = {0, 0, 0};
+    std::int32_t popTypeMaxPop[3] = {0, 0, 0};
+};
+
+OutputTuning read_tuning() {
+    OutputTuning t;
+    t.stationBonusImperialOutput =
+        global_const_via_slot<float>(A::GlobalConst_slot_STATION_BONUS_IMPERIAL_OUTPUT, 0.0f);
+    t.moraleIncreaseOutput =
+        global_const_via_slot<std::int32_t>(A::GlobalConst_slot_MORALE_INCREASE_OUTPUT, 0);
+    t.moraleIncreaseOutputMod =
+        global_const_via_slot<float>(A::GlobalConst_slot_MORALE_INCREASE_OUTPUT_MOD, 0.0f);
+    t.moraleDecreaseOutput =
+        global_const_via_slot<std::int32_t>(A::GlobalConst_slot_MORALE_DECREASE_OUTPUT, 0);
+    t.moraleDecreaseOutputMod =
+        global_const_via_slot<float>(A::GlobalConst_slot_MORALE_DECREASE_OUTPUT_MOD, 0.0f);
+    t.slavesOutputMod = global_const_at<float>(A::GlobalConst_storage_SLAVES_OUTPUT_MOD, 0.0f);
+    for (int i = 0; i < 3; ++i) {
+        const std::uintptr_t row = A::PopTypeTable_base + std::uintptr_t(i) * 0x30;
+        t.popTypeOut[i] = global_const_at<float>(row + 0x10, 0.0f);
+        t.popTypeMaxPop[i] = global_const_at<std::int32_t>(row + 0x8, 0);
+    }
+    return t;
+}
+
+sots::sim::TuningTable to_tuning(const OutputTuning& t) {
+    sots::sim::TuningTable out;
+    out.STATION_BONUS_IMPERIAL_OUTPUT = t.stationBonusImperialOutput;
+    out.MORALE_INCREASE_OUTPUT = t.moraleIncreaseOutput;
+    out.MORALE_INCREASE_OUTPUT_MOD = t.moraleIncreaseOutputMod;
+    out.MORALE_DECREASE_OUTPUT = t.moraleDecreaseOutput;
+    out.MORALE_DECREASE_OUTPUT_MOD = t.moraleDecreaseOutputMod;
+    out.SLAVES_OUTPUT_MOD = t.slavesOutputMod;
+    return out;
+}
+
+Tv tuning_tv(const OutputTuning& t) {
+    Tv s = tv::struct_();
+    s.add("STATION_BONUS_IMPERIAL_OUTPUT", tv::f32(t.stationBonusImperialOutput));
+    s.add("MORALE_INCREASE_OUTPUT", tv::i32(t.moraleIncreaseOutput));
+    s.add("MORALE_INCREASE_OUTPUT_MOD", tv::f32(t.moraleIncreaseOutputMod));
+    s.add("MORALE_DECREASE_OUTPUT", tv::i32(t.moraleDecreaseOutput));
+    s.add("MORALE_DECREASE_OUTPUT_MOD", tv::f32(t.moraleDecreaseOutputMod));
+    s.add("SLAVES_OUTPUT_MOD", tv::f32(t.slavesOutputMod));
+    s.add("poptype0_out", tv::f32(t.popTypeOut[0]));
+    s.add("poptype1_out", tv::f32(t.popTypeOut[1]));
+    s.add("poptype2_out", tv::f32(t.popTypeOut[2]));
+    s.add("poptype0_maxpop", tv::i32(t.popTypeMaxPop[0]));
+    s.add("poptype1_maxpop", tv::i32(t.popTypeMaxPop[1]));
+    s.add("poptype2_maxpop", tv::i32(t.popTypeMaxPop[2]));
+    return s;
+}
+
+// ---- per-call state ----------------------------------------------------------------------
+//
+// Neither function nests and the strategic pass is single-threaded, so the snapshot taken in
+// describe_args (before the original runs) reaches ours() through a static. Do not copy this
+// into a re-entrant hook.
+
+struct GroupState {
+    bool ok = false;
+    bool owned = false;
+    bool independent = false;
+    int morale = 0;
+    OutputTuning tuning;
+};
+GroupState g_group;
+
+struct TotalState {
+    bool ok = false;
+    sots::sim::BaseOutputInputs in;
+    sots::sim::OutputModifiers mods;
+    OutputTuning tuning;
+    // diagnostics that never enter ours()
+    std::int32_t systemIndex = 0;
+    std::int32_t ownerSpecies = -1;
+    std::int64_t slaveGroupPop = 0;
+    std::int32_t addictionSlots = 0;
+    float speciesResourceOutput = 0;
+    std::int32_t speciesBaseDemand = 0;
+};
+TotalState g_total;
+
+const void* species_def(int species) {
+    if (!g_env.exe_base || species < 0 || species > 6) return nullptr;
+    const void* p = reinterpret_cast<const void*>(A::SpeciesDefTable_base + g_env.exe_base +
+                                                  std::uintptr_t(species) * 0x184);
+    return readable(p, 0x54) ? p : nullptr;
+}
+
+int effective_species(const void* sys, const void* owner) {
+    const void* indi = ptr_at(sys, A::ServerSystem_off_Indi);
+    if (indi && readable(indi, 8)) return peek<std::int32_t>(indi, 4);
+    if (owner && readable(owner, A::ServerPlayer_off_Species + 4))
+        return peek<std::int32_t>(owner, A::ServerPlayer_off_Species);
+    return -1;
+}
+
+// The Morale object at +0x11c is {vptr, int[7]}, so the per-species word is at +0x120 + 4*sp.
+int morale_of(const void* sys, int species) {
+    if (species < 0 || species >= kSpeciesSlots) return 0;
+    const std::size_t off = A::ServerSystem_off_Morale + 4 + std::size_t(species) * 4;
+    if (!readable(sys, off + 4)) return 0;
+    return peek<std::int32_t>(sys, off);
+}
+
+}  // namespace
+
+void init_system_output(std::uintptr_t exe_base, void (*log_line)(const char* line)) {
+    g_env.exe_base = exe_base;
+    g_env.log_line = log_line;
+}
+
+// ---- GroupOutput --------------------------------------------------------------------------
+
+void ServerSystemGroupOutputHook::describe_args(std::vector<Tv>& out, void* self,
+                                                std::int32_t groupType, std::int32_t species,
+                                                double count) {
+    GroupState st;
+    st.tuning = read_tuning();
+    if (readable(self, kSystemGuardSize)) {
+        const void* owner = ptr_at(self, A::ServerSystem_off_PID);
+        st.owned = owner != nullptr;
+        st.independent = ptr_at(self, A::ServerSystem_off_Indi) != nullptr;
+        st.morale = morale_of(self, species);
+        st.ok = true;
+        out.push_back(tv::i32(peek<std::int32_t>(self, A::ServerSystem_off_Idx)).named("sysIdx"));
+    } else {
+        out.push_back(tv::null().named("sysIdx"));
+    }
+    g_group = st;
+
+    out.push_back(tv::ptr(self).named("this"));
+    out.push_back(tv::i32(groupType).named("groupType"));
+    out.push_back(tv::i32(species).named("species"));
+    out.push_back(tv::f64(count).named("count"));
+    out.push_back(tv::i32(st.morale).named("morale"));
+    out.push_back(tv::boolean(st.owned).named("owned"));
+    out.push_back(tv::boolean(st.independent).named("independent"));
+    out.push_back(tuning_tv(st.tuning).named("tuning"));
+}
+
+Tv ServerSystemGroupOutputHook::describe_ret(double r) { return tv::f64(r); }
+
+void ServerSystemGroupOutputHook::regions(std::vector<trace::Region>& out, void* self,
+                                          std::int32_t, std::int32_t, double) {
+    if (!readable(self, kSystemGuardSize)) return;
+    trace::Region g;
+    g.name = "guard:system";
+    g.ptr = self;
+    g.size = kSystemGuardSize;
+    g.kind = trace::Region::Kind::Guard;
+    out.push_back(g);
+}
+
+ServerSystemGroupOutputHook::Args ServerSystemGroupOutputHook::rebind(trace::Scratch&, void* self,
+                                                                     std::int32_t groupType,
+                                                                     std::int32_t species,
+                                                                     double count) {
+    return Args{self, groupType, species, count};
+}
+
+double ServerSystemGroupOutputHook::ours(void*, std::int32_t groupType, std::int32_t species,
+                                         double count) {
+    (void)species;
+    if (!g_group.ok) return 0.0;
+    if (groupType < 0 || groupType > 2) return 0.0;
+    sots::sim::GroupOutputInputs in;
+    in.group = static_cast<sots::sim::PopGroup>(groupType);
+    // The count arrives as a double that the original formed from an int64; recovering the
+    // integer keeps our arithmetic on the same path as the model's.
+    in.count = static_cast<std::int64_t>(count);
+    in.morale = g_group.morale;
+    in.stations = 0;  // declared input boundary -- see coverage()
+    in.owned = g_group.owned;
+    in.independent = g_group.independent;
+    return sots::sim::GroupOutput(in, to_tuning(g_group.tuning));
+}
+
+// ---- ComputeTotalOutput -------------------------------------------------------------------
+
+void ServerSystemComputeTotalOutputHook::describe_args(std::vector<Tv>& out, void* self,
+                                                       double overHarvestRate) {
+    TotalState st;
+    st.tuning = read_tuning();
+    if (readable(self, kSystemGuardSize)) {
+        const void* owner = ptr_at(self, A::ServerSystem_off_PID);
+        const bool independent = ptr_at(self, A::ServerSystem_off_Indi) != nullptr;
+        const int sp = effective_species(self, owner);
+
+        st.systemIndex = peek<std::int32_t>(self, A::ServerSystem_off_Idx);
+        st.ownerSpecies = sp;
+
+        std::int64_t resAvail = peek<std::int32_t>(self, A::ServerSystem_off_Res);
+        bool stripMines = false;
+        if (owner && readable(owner, A::ServerPlayer_off_SetupOutputMult + 4)) {
+            stripMines = peek<std::uint8_t>(owner, A::ServerPlayer_off_AMine) != 0;
+            st.mods.playerOutMod = peek<float>(owner, A::ServerPlayer_off_OutMod);
+            st.mods.rebOutMod = peek<float>(owner, A::ServerPlayer_off_RebOutMod);
+            st.mods.scOutMod = peek<float>(owner, A::ServerPlayer_off_ScOutMod);
+            st.mods.techOutMod = peek<float>(owner, A::ServerPlayer_off_SetupOutputMult);
+        }
+        if (stripMines) {
+            resAvail += peek<std::int32_t>(self, A::ServerSystem_off_MRes);
+            resAvail += peek<std::int32_t>(self, A::ServerSystem_off_ARes2);
+        }
+
+        sots::sim::BaseOutputInputs& in = st.in;
+        in.imperialPopulation = std::int64_t(peek<std::int32_t>(self, A::ServerSystem_off_pbon)) +
+                                std::int64_t(peek<std::int32_t>(self, A::ServerSystem_off_Pop));
+        // Group 0 is credited to the system's effective species only; every other species
+        // contributes nothing, which is why one int pair is the whole imperial term.
+        if (sp < 0) in.imperialPopulation = 0;
+        const void* pop2 = static_cast<const char*>(self) + A::ServerSystem_off_Pop2;
+        const void* pbon2 = static_cast<const char*>(self) + A::ServerSystem_off_pbon2;
+        for (int i = 0; i < kSpeciesSlots; ++i) {
+            st.slaveGroupPop += population_of(pop2, 2, i) + population_of(pbon2, 2, i);
+        }
+        if (sp >= 0 && sp < kSpeciesSlots) {
+            in.civilianPopulation = population_of(pop2, 1, sp) + population_of(pbon2, 1, sp);
+            in.civilianMorale = morale_of(self, sp);
+        }
+        in.slavePopulation = 0;  // declared input boundary -- see coverage()
+        in.stations = 0;         // declared input boundary
+        in.independent = independent;
+        in.transitResources = peek<std::int32_t>(self, A::ServerSystem_off_TRes);
+        in.resourcesAvailable = resAvail;
+        in.infra = peek<float>(self, A::ServerSystem_off_Infra);
+        in.infraBonus = peek<float>(self, A::ServerSystem_off_ibon);
+        in.overHarvestRate = overHarvestRate;
+
+        if (const void* def = species_def(sp)) {
+            st.speciesBaseDemand = peek<std::int32_t>(def, 0x4c);
+            st.speciesResourceOutput = peek<float>(def, 0x50);
+        }
+        in.speciesBaseDemand = st.speciesBaseDemand;
+        in.speciesResourceOutput = st.speciesResourceOutput;
+
+        st.mods.owned = owner != nullptr;
+        st.mods.rebelling = peek<std::int32_t>(self, A::ServerSystem_off_rbfl) != 0;
+        st.mods.systemOutMod = peek<float>(self, A::ServerSystem_off_OutMod);
+        st.mods.addictionPhase3 = false;  // declared input boundary
+        st.ok = true;
+    }
+    g_total = st;
+
+    out.push_back(tv::ptr(self).named("this"));
+    out.push_back(tv::f64(overHarvestRate).named("SRoh"));
+    out.push_back(tv::i32(st.systemIndex).named("sysIdx"));
+    out.push_back(tv::i32(st.ownerSpecies).named("species"));
+    out.push_back(tv::i64(st.in.imperialPopulation).named("imperialPop"));
+    out.push_back(tv::i64(st.in.civilianPopulation).named("civilianPop"));
+    out.push_back(tv::i64(st.slaveGroupPop).named("slaveGroupPop"));
+    out.push_back(tv::i32(st.in.civilianMorale).named("civilianMorale"));
+    out.push_back(tv::i64(st.in.resourcesAvailable).named("resAvail"));
+    out.push_back(tv::i64(st.in.transitResources).named("TRes"));
+    out.push_back(tv::f32(st.in.infra).named("Infra"));
+    out.push_back(tv::f32(st.in.infraBonus).named("ibon"));
+    out.push_back(tv::i32(st.speciesBaseDemand).named("speciesBaseDemand"));
+    out.push_back(tv::f32(st.speciesResourceOutput).named("speciesResourceOutput"));
+    out.push_back(tv::f32(static_cast<float>(st.mods.playerOutMod)).named("OutMod"));
+    out.push_back(tv::f32(static_cast<float>(st.mods.systemOutMod)).named("sysOutMod"));
+    out.push_back(tv::f32(static_cast<float>(st.mods.techOutMod)).named("setupOutMod"));
+    out.push_back(tv::f32(static_cast<float>(st.mods.rebOutMod)).named("RebOutMod"));
+    out.push_back(tv::f32(static_cast<float>(st.mods.scOutMod)).named("ScOutMod"));
+    out.push_back(tv::boolean(st.mods.rebelling).named("rebelling"));
+    out.push_back(tv::boolean(st.in.independent).named("independent"));
+    out.push_back(tuning_tv(st.tuning).named("tuning"));
+}
+
+Tv ServerSystemComputeTotalOutputHook::describe_ret(double r) { return tv::f64(r); }
+
+void ServerSystemComputeTotalOutputHook::regions(std::vector<trace::Region>& out, void* self,
+                                                 double) {
+    if (!readable(self, kSystemGuardSize)) return;
+    trace::Region g;
+    g.name = "guard:system";
+    g.ptr = self;
+    g.size = kSystemGuardSize;
+    g.kind = trace::Region::Kind::Guard;
+    out.push_back(g);
+}
+
+ServerSystemComputeTotalOutputHook::Args ServerSystemComputeTotalOutputHook::rebind(
+    trace::Scratch&, void* self, double overHarvestRate) {
+    return Args{self, overHarvestRate};
+}
+
+double ServerSystemComputeTotalOutputHook::ours(void*, double) {
+    if (!g_total.ok) return 0.0;
+    const sots::sim::TuningTable t = to_tuning(g_total.tuning);
+    sots::sim::OutputModifiers m = g_total.mods;
+    m.baseOutput = sots::sim::SystemBaseOutput(g_total.in, t);
+    return sots::sim::TotalSystemOutputRaw(m, t);
+}
+
+}  // namespace shim::hooks
diff --git a/src/shim/hooks/system_output.h b/src/shim/hooks/system_output.h
new file mode 100644
index 0000000..2e3242a
--- /dev/null
+++ b/src/shim/hooks/system_output.h
@@ -0,0 +1,111 @@
+// Hook descriptors for the two functions that turn a colony's population into output points
+// (lane N).
+//
+//   Game::ServerSystem::GroupOutput(this, groupType, species, count) -> double
+//   Game::ServerSystem::ComputeTotalOutput(this, overHarvestRate)    -> double
+//
+// Both are **side-effect free**: they and every one of their callees were checked for stores
+// to the game state before either was chosen as a compare target. That is the whole reason
+// the neighbouring `ComputeOutputFromRates` is *not* hooked here -- that one repairs damaged
+// ships in orbit, so running it twice would change the game.
+//
+// Neither declares a Result region: the thing being compared is the **return value**, which
+// the harness diffs like any other output. Each declares one Guard over the whole
+// ServerSystem, so a run that reports no undeclared writes is also evidence for the
+// read-only claim above rather than an assumption about it.
+//
+// GroupOutput is the interesting one. It is the population -> output law itself, it is called
+// up to 14 times per system per output pass, and its `count` arrives as an argument -- so the
+// compare tests the law without needing to model the population lookup, the capacity surplus
+// or the slave adjustment at all.
+#pragma once
+
+#include <cstdint>
+#include <tuple>
+#include <vector>
+
+#include "shim/trace/hook.h"
+
+namespace shim::hooks {
+
+struct ServerSystemGroupOutputHook {
+    static constexpr const char* name = "Game::ServerSystem::GroupOutput";
+    static constexpr trace::CallConv conv = trace::CallConv::Thiscall;
+    using Ret = double;
+    using Args = std::tuple<void*, std::int32_t, std::int32_t, double>;
+
+    static void describe_args(std::vector<trace::Tv>& out, void* self, std::int32_t groupType,
+                              std::int32_t species, double count);
+    static trace::Tv describe_ret(double r);
+    static void regions(std::vector<trace::Region>& out, void* self, std::int32_t groupType,
+                        std::int32_t species, double count);
+    static Args rebind(trace::Scratch& s, void* self, std::int32_t groupType,
+                       std::int32_t species, double count);
+    static double ours(void* self, std::int32_t groupType, std::int32_t species, double count);
+    static trace::HookPolicy policy() { return trace::HookPolicy{}; }
+    static void coverage(trace::Coverage& c) {
+        c.unmodelled("the station count that scales the imperial term",
+                     trace::Risk::High,
+                     "the original gets it from a helper that walks the system's fleets and "
+                     "their ships through virtual calls and takes the system in EBX, which a "
+                     "hook cannot call portably. `ours` therefore assumes ZERO stations. A "
+                     "divergence on an imperial row is expected to be exactly the station "
+                     "factor, and the record carries `count` and the return, so the factor is "
+                     "MEASURED from the trace rather than fitted",
+                     "declared input boundary; the trace makes it recoverable");
+        c.unmodelled("the slave row's output modifier, and every value the data files supply",
+                     trace::Risk::Medium,
+                     "SLAVES_OUTPUT_MOD, the two morale thresholds and their two modifiers, and "
+                     "STATION_BONUS_IMPERIAL_OUTPUT are read out of the live process's globals "
+                     "and logged with every record, so the record says which value drove it",
+                     "logged as `tuning` on every record");
+        c.complete("the imperial and civilian output modifiers, the 1.8 factor and the 500000 "
+                   "divisor are literals inside the executable, so nothing about them is "
+                   "assumed from the data files");
+    }
+};
+
+struct ServerSystemComputeTotalOutputHook {
+    static constexpr const char* name = "Game::ServerSystem::ComputeTotalOutput";
+    static constexpr trace::CallConv conv = trace::CallConv::Thiscall;
+    using Ret = double;
+    using Args = std::tuple<void*, double>;
+
+    static void describe_args(std::vector<trace::Tv>& out, void* self, double overHarvestRate);
+    static trace::Tv describe_ret(double r);
+    static void regions(std::vector<trace::Region>& out, void* self, double overHarvestRate);
+    static Args rebind(trace::Scratch& s, void* self, double overHarvestRate);
+    static double ours(void* self, double overHarvestRate);
+    static trace::HookPolicy policy() { return trace::HookPolicy{}; }
+    static void coverage(trace::Coverage& c) {
+        c.unmodelled("the station count, as for GroupOutput",
+                     trace::Risk::High,
+                     "`ours` assumes zero stations, so a system with an imperial population and "
+                     "a station diverges by the station factor",
+                     "declared input boundary");
+        c.unmodelled("the slave population and its xenotech adjustment",
+                     trace::Risk::High,
+                     "the original's slave count is not a plain field: it runs the count through "
+                     "a per-species xenotech factor. `ours` takes the slave term as ZERO, so any "
+                     "system holding slaves diverges. The record logs the raw group-2 population "
+                     "sums so a divergence can be attributed",
+                     "declared input boundary");
+        c.unmodelled("the capacity surplus the civilian term adds for the owner's own species",
+                     trace::Risk::Medium,
+                     "the original calls the carrying-capacity helper twice with different "
+                     "out-parameter slots and adds max(0, B - A) to the civilian count; `ours` "
+                     "uses the raw civilian population. The surplus is zero except when the "
+                     "colony is at its cap",
+                     "declared input boundary");
+        c.unmodelled("the addiction phase",
+                     trace::Risk::Low,
+                     "`ours` assumes it is below 3, so ADDICTION_OUTPUT_MOD never applies; the "
+                     "record logs the system's addiction table length so the case is visible");
+    }
+};
+
+// Process facts the hooks need (exe base for the globals, a line logger). Call once before
+// installing.
+void init_system_output(std::uintptr_t exe_base, void (*log_line)(const char* line));
+
+}  // namespace shim::hooks
diff --git a/src/shim/main.cpp b/src/shim/main.cpp
index bcf0bbd..617a525 100644
--- a/src/shim/main.cpp
+++ b/src/shim/main.cpp
@@ -18,6 +18,7 @@
 #include "shim/fpu_force.h"
 #include "shim/hooks/dictionaries.h"
 #include "shim/hooks/colony_turn.h"
+#include "shim/hooks/system_output.h"
 #include "shim/hooks/player_turn.h"
 #include "shim/hooks/compute_budget.h"
 #include "shim/hooks/fleet_movement.h"
@@ -165,6 +166,9 @@ using ProcessResearchHook = shim::trace::Hook<shim::hooks::TechTreeProcessResear
 using OnTechResearchedHook = shim::trace::Hook<shim::hooks::ServerPlayerOnTechResearchedHook>;
 using ComputeBudgetHook = shim::trace::Hook<shim::hooks::ComputeBudgetHook>;
 using ColonyTurnHook = shim::trace::Hook<shim::hooks::ServerSystemProcessTurnHook>;
+// Lane N: the population -> base-output term (docs/N-output-term.md).
+using GroupOutputHook = shim::trace::Hook<shim::hooks::ServerSystemGroupOutputHook>;
+using TotalOutputHook = shim::trace::Hook<shim::hooks::ServerSystemComputeTotalOutputHook>;
 using PlayerTurnHook = shim::trace::Hook<shim::hooks::ServerPlayerProcessTurnHook>;
 using MoveFleetHook = shim::trace::Hook<shim::hooks::StrategyServerMoveFleetHook>;
 using FleetMovementHook = shim::trace::Hook<shim::hooks::StrategyServerProcessFleetMovementHook>;
@@ -220,6 +224,11 @@ void InstallHooks(shim::trace::Tracer& tracer) {
     // points. All three are verified thiscall prototypes with no stack-argument surprises.
     shim::hooks::init_colony_turn(exeBase, &ShimLogLine);
     InstallTemplateHook<shim::hooks::ServerSystemProcessTurnHook>(tracer, exeBase, sots::addr::ServerSystem_ProcessTurn);
+    // Lane N: the two side-effect-free output functions. GroupOutput is the population ->
+    // output law itself; ComputeTotalOutput is the sum the budget roll-up ultimately reads.
+    shim::hooks::init_system_output(exeBase, &ShimLogLine);
+    InstallTemplateHook<shim::hooks::ServerSystemGroupOutputHook>(tracer, exeBase, sots::addr::ServerSystem_GroupOutput);
+    InstallTemplateHook<shim::hooks::ServerSystemComputeTotalOutputHook>(tracer, exeBase, sots::addr::ServerSystem_ComputeTotalOutput);
     // Lane T: the per-player turn driver (once per player per turn). Verified thiscall with
     // one ignored float argument; see docs/T-turn-driver.md.
     shim::hooks::init_player_turn(exeBase, &ShimLogLine);
@@ -310,6 +319,8 @@ void Shim_Init(HMODULE self) {
     ProcessResearchHook::register_policy(tracer);
     OnTechResearchedHook::register_policy(tracer);
     ColonyTurnHook::register_policy(tracer);
+    GroupOutputHook::register_policy(tracer);
+    TotalOutputHook::register_policy(tracer);
     PlayerTurnHook::register_policy(tracer);
     MoveFleetHook::register_policy(tracer);
     FleetMovementHook::register_policy(tracer);
diff --git a/src/shim/shim.cfg.output b/src/shim/shim.cfg.output
new file mode 100644
index 0000000..8477624
--- /dev/null
+++ b/src/shim/shim.cfg.output
@@ -0,0 +1,31 @@
+# Lane N -- the population -> base-output term, in compare mode.
+# `hooks=off` short-circuits before any hook is installed, so the default must be `trace`
+# and every other hook turned off by name.
+hooks=trace
+hook.Shim::SelfTest::Fill=off
+hook.Shim::SelfTest::FillGuard=off
+hook.Shim::SelfTest::FillGuardLying=off
+hook.Shim::SelfTest::FillThrows=off
+hook.Shim::SelfTest::FillWrong=off
+hook.Mars::GlobalConsts::LoadFile=off
+hook.Game::WeaponDictionary::Init=off
+hook.Game::SectionDictionary::SectionDictionary=off
+hook.Game::ServerPlayer::ComputeBudget=off
+hook.Game::TechTree::ProcessResearch=off
+hook.Game::ServerPlayer::OnTechResearched=off
+hook.Game::ServerSystem::ProcessTurn=off
+hook.Game::ServerPlayer::ProcessTurn=off
+hook.Game::StrategyServer::MoveFleet=off
+hook.Game::StrategyServer::ProcessFleetMovement=off
+hook.Game::StrategyHost::Autosave=off
+hook.Game::StrategyServer::ProcessTurn=off
+hook.Game::StrategyServer::OnAllCombatDone_Tail=off
+hook.Game::StrategyServer::ApplyEncounterResult=off
+hook.Game::StrategyServer::NodeLineDecay=off
+hook.Game::StrategyServer::ProcessNodeSpaceTravel=off
+hook.Game::EncounterDetect::AssignContacts=off
+hook.Game::ServerSystem::GroupOutput=compare
+hook.Game::ServerSystem::ComputeTotalOutput=compare
+trace.path=C:\SOTS\shim.trace.jsonl
+trace.inline_max=256
+trace.flush=always
diff --git a/tests/game_sim/test_colony.cpp b/tests/game_sim/test_colony.cpp
index 1a4ed05..b37771d 100644
--- a/tests/game_sim/test_colony.cpp
+++ b/tests/game_sim/test_colony.cpp
@@ -270,21 +270,112 @@ static void test_output() {
     CHECK_NEAR(MoraleOutputMultiplier(75, t), 1.1, 0.0);
     CHECK_NEAR(MoraleOutputMultiplier(50, t), 1.0, 0.0);
     CHECK_NEAR(MoraleOutputMultiplier(25, t), 0.9, 0.0);
+    // A morale entry of exactly 0 means "no record": the thresholds are not consulted,
+    // which matters because 0 <= MORALE_DECREASE_OUTPUT would otherwise apply the penalty.
+    CHECK_NEAR(MoraleOutputMultiplier(0, t), 1.0, 0.0);
+    // A modifier that is not strictly positive is ignored (an unloaded tuning table has
+    // every field at zero, and a zero multiplier would silently wipe the term).
+    TuningTable zero;
+    zero.MORALE_INCREASE_OUTPUT = 60;
+    CHECK_NEAR(MoraleOutputMultiplier(80, zero), 1.0, 0.0);
 
     OutputModifiers m;
     m.baseOutput = 1000;
-    m.morale = 80;
-    m.stations = 1;
-    CHECK_NEAR(TotalSystemOutput(m, t), 1210.0, 0.0);        // 1000 x 1.1 x 1.1
+    CHECK_NEAR(TotalSystemOutput(m, t), 1000.0, 0.0);
     m.addictionPhase3 = true;
-    CHECK_NEAR(TotalSystemOutput(m, t), 605.0, 0.0);
+    CHECK_NEAR(TotalSystemOutput(m, t), 500.0, 0.0);
     m.addictionPhase3 = false;
     m.playerOutMod = 0.5;
     m.systemOutMod = 0.5;
+    CHECK_NEAR(TotalSystemOutput(m, t), 250.0, 0.0);
     // B4: the engine's round is ties-to-EVEN, so 302.5 goes DOWN to 302 (it used to be 303)
+    m.baseOutput = 1210;
     CHECK_NEAR(TotalSystemOutput(m, t), 302.0, 0.0);
     m.baseOutput = 0;
     CHECK_NEAR(TotalSystemOutput(m, t), 0.0, 0.0);
+    // No owner and a rebelling system both return zero before any multiplier runs.
+    m.baseOutput = 1000;
+    m.playerOutMod = 1.0;
+    m.systemOutMod = 1.0;
+    m.owned = false;
+    CHECK_NEAR(TotalSystemOutput(m, t), 0.0, 0.0);
+    m.owned = true;
+    m.rebelling = true;
+    CHECK_NEAR(TotalSystemOutput(m, t), 0.0, 0.0);
+    m.rebelling = false;
+
+    // ---- the population -> output term (lane N) ----------------------------------------
+    // Output per head is typeOutputMod x 1.8 / 500000; the imperial row's modifier is 1.
+    GroupOutputInputs g;
+    g.group = PopGroup::Imperial;
+    g.count = 2000000000LL;
+    CHECK_NEAR(GroupOutput(g, t), 7200.0, 1e-9);             // 2e9 / 5e5 x 1.8
+    g.stations = 2;                                          // 1 + 2 x 0.1
+    CHECK_NEAR(GroupOutput(g, t), 8640.0, 1e-9);
+    g.stations = 0;
+    g.count = 0;
+    CHECK_NEAR(GroupOutput(g, t), 0.0, 0.0);
+    g.count = -5;
+    CHECK_NEAR(GroupOutput(g, t), 0.0, 0.0);
+    // The station bonus is imperial-only, and civilians carry the morale multiplier.
+    g.group = PopGroup::Civilian;
+    g.count = 500000000LL;
+    g.stations = 4;
+    g.morale = 0;
+    CHECK_NEAR(GroupOutput(g, t), 500000000.0 / 500000.0 * F32(0.33) * 1.8, 1e-9);
+    g.morale = 80;                                           // above MORALE_INCREASE_OUTPUT
+    CHECK_NEAR(GroupOutput(g, t), 500000000.0 / 500000.0 * F32(0.33) * 1.8 * 1.1, 1e-9);
+    g.independent = true;                                    // an independent colony has no morale
+    CHECK_NEAR(GroupOutput(g, t), 500000000.0 / 500000.0 * F32(0.33) * 1.8, 1e-9);
+
+    // The whole base-output sum on the reference save's human homeworld, with the two
+    // data-file species fields left at zero so only the terms the executable carries move.
+    BaseOutputInputs b;
+    b.imperialPopulation = 2000000000LL;   // Pop 1e9 + pbon 1e9
+    b.civilianPopulation = 500000000LL;
+    b.civilianMorale = 75;
+    b.transitResources = 0;
+    b.resourcesAvailable = 5000;
+    b.infra = 1.0f;
+    b.infraBonus = 1.0f;
+    b.overHarvestRate = 0.0;
+    // cbrt(2e9/100) x 0.01 = 2.71 -> clamps to 1, and a clamped value at or above 1 - 1e-4
+    // is *substituted* by the infrastructure term rather than capping it. Infra + ibon = 2
+    // here, so the fraction is 2, not 1 -- the branch is a substitution, not a min, and a
+    // pending infrastructure bonus can push a colony's extraction above unity.
+    CHECK_NEAR(StripMineFraction({b.imperialPopulation, b.infra, b.infraBonus}), 2.0f, 0.0);
+    // ... and a colony whose population term has not saturated is capped by it as usual.
+    CHECK_NEAR(StripMineFraction({1000000, 0.4f, 0.0f}), 0.21544346f, 1e-6f);
+    CHECK_NEAR(StripMineFraction({100000000LL, 0.4f, 0.0f}), 0.4f, 0.0);
+    const double expected = 7200.0 + 500000000.0 / 500000.0 * F32(0.33) * 1.8 * 1.1 + 9000.0;
+    CHECK_NEAR(SystemBaseOutput(b, t), expected, 1e-6);
+    // Linear in population: a tenth of the imperial pop is a tenth of that term.
+    b.imperialPopulation = 200000000LL;
+    b.civilianPopulation = 0;
+    b.resourcesAvailable = 0;
+    CHECK_NEAR(SystemBaseOutput(b, t), 720.0, 1e-9);
+    // With SRoh = 0 the over-harvest demand degenerates to min(available, speciesBaseDemand).
+    OverHarvestInputs oh;
+    oh.resourcesAvailable = 5000;
+    oh.population = 2000000000LL;
+    oh.speciesBaseDemand = 120;
+    CHECK_NEAR(OverHarvestDemand(oh), 120.0, 0.0);
+    oh.speciesBaseDemand = 9000;
+    CHECK_NEAR(OverHarvestDemand(oh), 5000.0, 0.0);
+    // ... and with SRoh > 0 it adds rate x available x clamp01(pop x 1e-5), floored at 1.
+    oh.speciesBaseDemand = 0;
+    oh.overHarvestRate = 0.5;
+    CHECK_NEAR(OverHarvestDemand(oh), 2500.0, 1e-9);         // clamp01(2e9 x 1e-5) = 1
+    oh.population = 10000;                                   // clamp01(0.1)
+    CHECK_NEAR(OverHarvestDemand(oh), 250.0, 1e-9);
+    oh.population = 0;                                       // the floor of 1, not 0
+    CHECK_NEAR(OverHarvestDemand(oh), 1.0, 0.0);
+
+    // The population-type table the executable builds in code.
+    CHECK_NEAR(PopTypeOf(PopGroup::Imperial, t).outputMod, 1.0, 0.0);
+    CHECK_NEAR(PopTypeOf(PopGroup::Civilian, t).outputMod, F32(0.33), 0.0);
+    CHECK_EQ(static_cast<int>(PopTypeOf(PopGroup::Imperial, t).maxPopulation), 50000000);
+    CHECK_EQ(static_cast<int>(PopTypeOf(PopGroup::Civilian, t).maxPopulation), 20000000);
     CHECK_NEAR(RoundHalfEven(0.5), 0.0, 0.0);
     CHECK_NEAR(RoundHalfEven(1.5), 2.0, 0.0);
     CHECK_NEAR(RoundHalfEven(-2.5), -2.0, 0.0);
diff --git a/tests/game_sim/test_economy.cpp b/tests/game_sim/test_economy.cpp
index 08ccade..65c8227 100644
--- a/tests/game_sim/test_economy.cpp
+++ b/tests/game_sim/test_economy.cpp
@@ -326,6 +326,17 @@ static void test_bankruptcy() {
     CHECK_EQ(l.eliminationFloor, -2000000000);
     CHECK_EQ(l.protectionLimit, -1320000000);
 
+    // LANE N: the divisor is the widened float literal, not the decimal -0.15. The two
+    // disagree for every maxIncome divisible by 3, and maxIncome = 3 is where it first
+    // bites: 3 / -0.15 is -20 exactly in decimal but -19.99999920... with the image's
+    // constant, and the conversion TRUNCATES.
+    CHECK_EQ(ComputeBankruptcyLimits(3, t).eliminationFloor, -19);
+    CHECK_EQ(ComputeBankruptcyLimits(6, t).eliminationFloor, -39);
+    CHECK_EQ(ComputeBankruptcyLimits(9, t).eliminationFloor, -59);
+    // ... and above ~3,000,000 maximum income they differ on essentially every value.
+    CHECK_EQ(ComputeBankruptcyLimits(238592, t).eliminationFloor, -1590613);
+    CHECK_EQ(ComputeBankruptcyLimits(3000001, t).eliminationFloor, -20000005);
+
     BankruptcyLimits none = ComputeBankruptcyLimits(0, t);
     CHECK_EQ(none.eliminationFloor, 0);
     CHECK_EQ(none.protectionLimit, 0);