diff --git a/plugins/clone-app/skills/clone-app/references/unity-re-guide.md b/plugins/clone-app/skills/clone-app/references/unity-re-guide.md
index b185dd8..4b4e0ac 100644
--- a/plugins/clone-app/skills/clone-app/references/unity-re-guide.md
+++ b/plugins/clone-app/skills/clone-app/references/unity-re-guide.md
@@ -38,3 +38,18 @@ then writes a partial `unity-digest.md` and sets `RE Method: limited: unity-no-t
 Extracted game art is copyrighted. Outside authorized use (own game, lawful
 research), treat extracted assets as **reference only** and recreate in the same
 style — do not ship them.
+
+## Game mechanics & formulas (fidelity pass)
+
+In the Phase 8 fidelity pass, deepen `$WORK/unity-digest.md` beyond the type
+model + netcode to capture the playable rules:
+
+- **Game mechanics** — core loop, win/lose conditions, level/wave progression,
+  player/enemy state machines (from the C# `MonoBehaviour` methods).
+- **Formulas** — damage/score/economy/cooldown calculations, drop rates, curve
+  tables (constants and arithmetic in the decompiled C#).
+- **Tunables** — `ScriptableObject` configs and serialized fields that balance
+  the game.
+
+Confidence: Unity **mono** is near-source (high); **il2cpp** gives signatures +
+partial bodies (med). State the level reached.
diff --git a/plugins/clone-app/tests/test-references-content.sh b/plugins/clone-app/tests/test-references-content.sh
index 6fcab40..fc97185 100755
--- a/plugins/clone-app/tests/test-references-content.sh
+++ b/plugins/clone-app/tests/test-references-content.sh
@@ -36,5 +36,6 @@ has "$R/clone-build-spec-template.md" "User-flow diagrams"
 has "$R/clone-build-spec-template.md" "Backend rebuild spec"
 has "$R/clone-build-spec-template.md" "nav-graph.json"
 has "$R/clone-build-spec-template.md" "logic-digest.md"
+has "$R/unity-re-guide.md" "Game mechanics"
 
 exit $fail