diff --git a/README.md b/README.md
index c9cbda7..97b6ec5 100644
--- a/README.md
+++ b/README.md
@@ -104,13 +104,22 @@ This game is a **decision simulator** for our actual work.
 
 ## Files
 
-- `index.html` — Game UI
-- `game.js` — Core engine (tick loop, buildings, projects, events)
+- `index.html` — Game UI (entry point)
+- `js/main.js` — Bootstrap: binds UI, starts the tick loop
+- `js/engine.js` — Core engine (tick loop, buildings, projects, events)
+- `js/data.js` — Game data, constants, and configuration
+- `js/utils.js` — Shared helper functions
+- `js/combat.js` — Combat and threat mechanics
+- `js/strategy.js` — AI strategy decisions
+- `js/sound.js` — Audio and music
+- `js/render.js` — DOM rendering and UI updates
+- `js/tutorial.js` — New-player tutorial flow
+- `js/dismantle.js` — Dismantle / teardown mechanics
+- `js/emergent-mechanics.js` — Emergent gameplay systems
 - `DESIGN.md` — Full design document with narrative arc and mechanics
 - `README.md` — This file
 
 ## No Build Required
-
 This is a static HTML/JS game. Just open `index.html` in a browser.
 
 ---
diff --git a/tests/test_readme_runtime_map.py b/tests/test_readme_runtime_map.py
new file mode 100644
index 0000000..44de66a
--- /dev/null
+++ b/tests/test_readme_runtime_map.py
@@ -0,0 +1,70 @@
+"""
+Regression test: README file map must stay in sync with scripts loaded by index.html.
+
+Catches stale references (e.g. the old game.js) and missing documentation for
+any new modules added to the runtime.
+"""
+
+import re
+from pathlib import Path
+
+REPO_ROOT = Path(__file__).resolve().parent.parent
+INDEX_HTML = REPO_ROOT / "index.html"
+README_MD = REPO_ROOT / "README.md"
+
+
+def _scripts_from_index_html() -> set[str]:
+    """Return the set of .js paths referenced in <script src="..."> tags."""
+    html = INDEX_HTML.read_text(encoding="utf-8")
+    return set(re.findall(r'<script\s+src="([^"]+\.js)"', html))
+
+
+def _scripts_from_readme() -> set[str]:
+    """Return the set of js/ paths mentioned in the README Files section."""
+    text = README_MD.read_text(encoding="utf-8")
+    # Grab everything between "## Files" and the next "## " heading
+    m = re.search(r"## Files\n(.*?)(?=\n## |\Z)", text, re.DOTALL)
+    assert m, "README is missing a '## Files' section"
+    files_section = m.group(1)
+    return set(re.findall(r"`(js/[^`]+\.js)`", files_section))
+
+
+def test_no_stale_game_js_reference():
+    """README must not reference the old monolithic game.js."""
+    text = README_MD.read_text(encoding="utf-8")
+    # Only flag if game.js appears *inside* the Files section (not elsewhere in prose)
+    m = re.search(r"## Files\n(.*?)(?=\n## |\Z)", text, re.DOTALL)
+    assert m, "README is missing a '## Files' section"
+    files_section = m.group(1)
+    assert "game.js" not in files_section, (
+        "Stale reference to game.js found in README Files section"
+    )
+
+
+def test_readme_covers_all_runtime_scripts():
+    """Every <script> in index.html must be documented in the README."""
+    loaded = _scripts_from_index_html()
+    documented = _scripts_from_readme()
+    undocumented = loaded - documented
+    assert not undocumented, (
+        f"Scripts loaded by index.html but missing from README: {undocumented}"
+    )
+
+
+def test_readme_has_no_extra_scripts():
+    """README should not document scripts that index.html does not load."""
+    loaded = _scripts_from_index_html()
+    documented = _scripts_from_readme()
+    extra = documented - loaded
+    assert not extra, (
+        f"Scripts documented in README but not loaded by index.html: {extra}"
+    )
+
+
+def test_main_js_is_entry_point():
+    """README should identify js/main.js as the entry / bootstrap point."""
+    text = README_MD.read_text(encoding="utf-8")
+    m = re.search(r"## Files\n(.*?)(?=\n## |\Z)", text, re.DOTALL)
+    assert m, "README is missing a '## Files' section"
+    files_section = m.group(1)
+    assert "main.js" in files_section, "README Files section should mention js/main.js"