diff --git a/docs/REFERENCE.md b/docs/REFERENCE.md
index 0bc83763..0163b79d 100644
--- a/docs/REFERENCE.md
+++ b/docs/REFERENCE.md
@@ -133,7 +133,7 @@ Override score, severity, or enable/disable individual rules:
 
 | Rule ID | Default Score | Default Severity |
 |---------|--------------|-----------------|
-| `non-standard-naming` | -1 | suggestion |
+| `non-standard-naming` | -3 | suggestion |
 | `non-semantic-name` | -1 | suggestion |
 | `inconsistent-naming-convention` | -1 | suggestion |
 <!-- RULE_TABLE_END -->
diff --git a/src/core/engine/scoring.test.ts b/src/core/engine/scoring.test.ts
index 68e502ec..713c9321 100644
--- a/src/core/engine/scoring.test.ts
+++ b/src/core/engine/scoring.test.ts
@@ -1,4 +1,4 @@
-import { calculateScores, formatScoreSummary, gradeToClassName, getCategoryLabel, getSeverityLabel, buildResultJson } from "./scoring.js";
+import { calculateScores, formatScoreSummary, gradeToClassName, getCategoryLabel, getSeverityLabel, buildResultJson, CATEGORY_WEIGHT } from "./scoring.js";
 import type { AnalysisIssue, AnalysisResult } from "./rule-engine.js";
 import type { AnalysisFile, AnalysisNode } from "../contracts/figma-node.js";
 import type { Rule, RuleConfig, RuleViolation } from "../contracts/rule.js";
@@ -226,17 +226,13 @@ describe("calculateScores", () => {
       makeIssue({ ruleId: "no-auto-layout", category: "pixel-critical", severity: "blocking" }),
     ], 100));
 
-    const categoryPercentages = [
-      scores.byCategory["pixel-critical"].percentage,
-      scores.byCategory["responsive-critical"].percentage,
-      scores.byCategory["code-quality"].percentage,
-      scores.byCategory["token-management"].percentage,
-      scores.byCategory["interaction"].percentage,
-      scores.byCategory["minor"].percentage,
-    ];
-    const expectedOverall = Math.round(
-      categoryPercentages.reduce((a, b) => a + b, 0) / 6
-    );
+    let weightedSum = 0;
+    let totalWeight = 0;
+    for (const [cat, w] of Object.entries(CATEGORY_WEIGHT)) {
+      weightedSum += scores.byCategory[cat as Category].percentage * w;
+      totalWeight += w;
+    }
+    const expectedOverall = Math.round(weightedSum / totalWeight);
     expect(scores.overall.percentage).toBe(expectedOverall);
   });
 
diff --git a/src/core/engine/scoring.ts b/src/core/engine/scoring.ts
index 0b0d2dd6..93ab8b15 100644
--- a/src/core/engine/scoring.ts
+++ b/src/core/engine/scoring.ts
@@ -85,19 +85,23 @@ function computeTotalScorePerCategory(
 }
 
 /**
- * Category weights for overall score.
- * All equal (1.0) by design — no category is inherently more important than another.
- * This avoids subjective bias; individual rule scores within each category already
- * encode relative importance. If calibration reveals certain categories correlate
- * more strongly with visual-compare similarity, these weights can be adjusted.
+ * Category weights for overall score, based on ablation experiment data (PR #149, #150).
+ *
+ * Evidence:
+ * - responsive-critical: ΔV +15.9% at expanded viewport, mobile-shop +46% — highest impact
+ * - pixel-critical: ΔV +5.4% when layout info stripped — direct pixel accuracy impact
+ * - token-management: ΔV +3.5% (style-ref, Phase 2) — moderate
+ * - code-quality: ΔV ≈0%, CSS classes -8~15 — affects structure, not pixels
+ * - interaction: data incomplete (missing-prototype disabled, #139 fixture rebuild pending)
+ * - minor: ΔV <2%, negligible code difference
  */
-const CATEGORY_WEIGHT: Record<Category, number> = {
-  "pixel-critical": 1.0,
-  "responsive-critical": 1.0,
+export const CATEGORY_WEIGHT: Record<Category, number> = {
+  "pixel-critical": 2.5,
+  "responsive-critical": 3.0,
   "code-quality": 1.0,
   "token-management": 1.0,
-  "interaction": 1.0,
-  "minor": 1.0,
+  "interaction": 0.5,
+  "minor": 0.3,
 };
 
 /**
diff --git a/src/core/rules/rule-config.ts b/src/core/rules/rule-config.ts
index 36bfdcd0..956d8cdc 100644
--- a/src/core/rules/rule-config.ts
+++ b/src/core/rules/rule-config.ts
@@ -131,13 +131,13 @@ export const RULE_CONFIGS: Record<RuleId, RuleConfig> = {
   "missing-prototype": {
     severity: "missing-info",
     score: -3,
-    enabled: true,
+    enabled: false, // disabled: interactionDestinations data missing from fixtures (#139)
   },
 
   // ── Minor ──
   "non-standard-naming": {
     severity: "suggestion",
-    score: -1,
+    score: -3, // higher than other naming rules: non-standard state names break interaction detection pipeline
     enabled: true,
   },
   "non-semantic-name": {