diff --git a/DECISIONS.md b/DECISIONS.md
index 54dda70..29450a5 100644
--- a/DECISIONS.md
+++ b/DECISIONS.md
@@ -1135,3 +1135,8 @@ Implementation decisions not spelled out in `memory-bank/implementation-plan.md`
 - **Handling time becomes per model where set** (`ShipModel.handlingGameHoursPerTonne`, optional, defaulting to the game-wide value); upgrades scale the model's own base.
 - **Roles are content** (`role`), one line per model including the loaner, for the Market (10L.7).
 - **The new sprites are listed in the manifest as pending** (`file: null`) so the "every ship has a sprite in the manifest" test holds; they use the placeholder until art arrives (10L.10).
+
+## Step 10L.2
+
+- **The factor applies to the whole leg from the origin** (decision 0.5.78): `checkRoute` is the single range check, so dispatch, reposition, the board's eligibility and the map pick it up together. The destination's factor plays no part in that leg.
+- **The dispatch sheet quotes range from the origin**, rounded, e.g. "reaches 130M km from Moon", so the number matches what the check used.
diff --git a/apps/web/src/screens/DispatchSheet.tsx b/apps/web/src/screens/DispatchSheet.tsx
index 0dbfb49..67be7b1 100644
--- a/apps/web/src/screens/DispatchSheet.tsx
+++ b/apps/web/src/screens/DispatchSheet.tsx
@@ -4,6 +4,7 @@ import {
   checkRoute,
   contractTripGameHours,
   isInShop,
+  rangeFrom,
   pilotShare,
   dutyAfterTrip,
   LONG_HAUL_SKILL_ID,
@@ -92,7 +93,7 @@ export function explainProblems(
   if (!route.ok) {
     problems.push(
       route.reason === "out-of-range"
-        ? `Out of range right now (${model.name} reaches ${model.fuelRangeMillionKm}M km)`
+        ? `Out of range right now (${model.name} reaches ${Math.round(rangeFrom(model, location(contract.originId)))}M km from ${locationName(contract.originId)})`
         : INELIGIBLE_REASONS["cannot-land"],
     );
   }
diff --git a/memory-bank/progress.md b/memory-bank/progress.md
index e7a076f..0657655 100644
--- a/memory-bank/progress.md
+++ b/memory-bank/progress.md
@@ -270,7 +270,7 @@ Spec: `memory-bank/change-requests/CR-011-settings-backup.md` (received as "CR-0
 Spec: `memory-bank/change-requests/CR-012-lighter-clipper-range.md` (received as "CR-009 … Phase 10I"). New decisions recorded as plan §0.5.77–0.5.81; §0.5.67 and §0.5.68 amended.
 
 - [x] **Step 10L.1 — Content: range factors and new ships.** `Location.launchRangeFactor` (Earth 1, Moon 1.3, Mars 1.15, Ceres 1.3, Jupiter 1). `ShipModel.role` (all six) and optional `ShipModel.handlingGameHoursPerTonne` (the sim's effective stats now start from it). New models: **Lighter** (42,400 cr, 1.6M km/h, 80 t, range 10, overhead 2 h, handling 0.012 h/t, fuel 350/M km) and **Clipper** (61,600 cr, 6.5M km/h, 30 t, range 198, overhead 2 h, fuel 600/M km); archetypes `lighter`, `clipper`. Config `noStrandMarginGameHours` 48. Manifest lists `ship-lighter` / `ship-clipper` as pending art. Tests: the CR's orderings replace Step 2.3's (`ships.test.ts`), range factors (`locations.test.ts`), Lighter handling (`effective-stats.test.ts`).
-- [ ] Step 10L.2 — Sim: effective range from origin
+- [x] **Step 10L.2 — Sim: effective range from origin.** `rangeFrom(ship, from)` = range × origin's `launchRangeFactor`; `checkRoute` compares the leg against it (dispatch, reposition, board eligibility and the map all go through it). The dispatch sheet quotes range from the origin. Tests (`range-from.test.ts`): 100 → 130 from the Moon and 115 from Mars; a leg between 1× and 1.3× fails from Earth and passes from the Moon; with every factor 1 the result matches the old check over 16 years of samples.
 - [ ] Step 10L.3 — Sim: no-strand rule
 - [ ] Step 10L.4 — Content tuning: reach table
 - [ ] Step 10L.5 — Upgrade caps for the new lineup
diff --git a/packages/sim/src/eligibility.ts b/packages/sim/src/eligibility.ts
index 01caaf8..1d68b17 100644
--- a/packages/sim/src/eligibility.ts
+++ b/packages/sim/src/eligibility.ts
@@ -11,7 +11,18 @@ export function canLandAt(ship: ShipModel, location: Location): boolean {
   return LANDING_RANK[ship.landingClass] >= LANDING_RANK[location.landingRequirement];
 }
 
-/** Whether a ship can fly from one location to another at a game time, or why not. */
+/**
+ * A ship's range for a leg launched from `from` (decisions 0.5.77, 0.5.78):
+ * its (effective) range times the origin's launch range factor.
+ */
+export function rangeFrom(ship: ShipModel, from: Location): number {
+  return ship.fuelRangeMillionKm * from.launchRangeFactor;
+}
+
+/**
+ * Whether a ship can fly from one location to another at a game time, or why
+ * not. Range is per leg, from the origin, at departure (decision 0.5.77).
+ */
 export function checkRoute(
   ship: ShipModel,
   from: Location,
@@ -19,7 +30,7 @@ export function checkRoute(
   gameTime: GameTime,
 ): RouteCheck {
   if (!canLandAt(ship, to)) return { ok: false, reason: "cannot-land" };
-  if (routeDistance(from, to, gameTime) > ship.fuelRangeMillionKm) {
+  if (routeDistance(from, to, gameTime) > rangeFrom(ship, from)) {
     return { ok: false, reason: "out-of-range" };
   }
   return { ok: true };
diff --git a/packages/sim/src/index.ts b/packages/sim/src/index.ts
index 508ad09..7c0f982 100644
--- a/packages/sim/src/index.ts
+++ b/packages/sim/src/index.ts
@@ -14,7 +14,7 @@ export { routeDistance } from "./distance";
 export { travelTimeGameHours } from "./travel";
 export { fuelCost } from "./fuel";
 
-export { canLandAt, checkRoute } from "./eligibility";
+export { canLandAt, checkRoute, rangeFrom } from "./eligibility";
 export type { RouteCheck } from "./eligibility";
 
 export { contractPayout } from "./contract";
diff --git a/packages/sim/test/range-from.test.ts b/packages/sim/test/range-from.test.ts
new file mode 100644
index 0000000..dae3a70
--- /dev/null
+++ b/packages/sim/test/range-from.test.ts
@@ -0,0 +1,46 @@
+import { content, type Location, type ShipModel } from "@deadhead/content";
+import { describe, expect, it } from "vitest";
+import { checkRoute, rangeFrom, realToGame, routeDistance } from "../src/index";
+
+const loc = (id: string) => content.location(id)!;
+const courier = content.shipModel("courier")!;
+const withRange = (range: number): ShipModel => ({ ...courier, fuelRangeMillionKm: range });
+const start = realToGame(Date.parse(content.config.epoch.realStart), content.config);
+const MONTH = 30.44 * 24 * 3_600_000;
+const samples = Array.from({ length: 16 * 12 + 1 }, (_, i) => start + i * MONTH);
+
+describe("range from the origin (Step 10L.2)", () => {
+  it("stretches a 100M km range to 130 from the Moon and 115 from Mars", () => {
+    expect(rangeFrom(withRange(100), loc("earth"))).toBe(100);
+    expect(rangeFrom(withRange(100), loc("moon"))).toBeCloseTo(130);
+    expect(rangeFrom(withRange(100), loc("mars"))).toBeCloseTo(115);
+  });
+
+  it("passes a leg from the Moon that fails from Earth when it is between 1× and 1.3× range", () => {
+    const t = samples[0]!;
+    const d = routeDistance(loc("moon"), loc("mars"), t);
+    const ship = withRange(d / 1.2);
+    expect(routeDistance(loc("earth"), loc("mars"), t)).toBeGreaterThan(ship.fuelRangeMillionKm);
+    expect(checkRoute(ship, loc("earth"), loc("mars"), t)).toEqual({
+      ok: false,
+      reason: "out-of-range",
+    });
+    expect(checkRoute(ship, loc("moon"), loc("mars"), t)).toEqual({ ok: true });
+  });
+
+  it("matches the old check exactly when every factor is 1", () => {
+    const flat = (l: Location): Location => ({ ...l, launchRangeFactor: 1 });
+    const ids = ["earth", "moon", "mars", "ceres-station", "jupiter-cloud-platform"];
+    for (const range of [5, 198, 450, 1250]) {
+      for (const from of ids) {
+        for (const to of ids) {
+          if (from === to) continue;
+          for (const t of samples) {
+            const old = routeDistance(loc(from), loc(to), t) <= range;
+            expect(checkRoute(withRange(range), flat(loc(from)), flat(loc(to)), t).ok).toBe(old);
+          }
+        }
+      }
+    }
+  });
+});