diff --git a/docs/reviews/2026-04-03-game-design-branch-docs-review.md b/docs/reviews/2026-04-03-game-design-branch-docs-review.md
index b3840de..dcd81b0 100644
--- a/docs/reviews/2026-04-03-game-design-branch-docs-review.md
+++ b/docs/reviews/2026-04-03-game-design-branch-docs-review.md
@@ -57,4 +57,5 @@ None identified.
 ## Verification
 
 - Re-run locally: `pip install -r scripts/requirements-content.txt && python scripts/validate_content.py && python scripts/check_decomposition_language.py`
+- If **`pip install`** fails with **PEP 668** (externally managed environment), use a venv (e.g. `python3 -m venv .venv-content`, then `.venv-content/bin/pip install -r scripts/requirements-content.txt` — `.venv-content/` is gitignored) or rely on the **PR gate** workflow for the same checks.
 - Before merge: grep for **`epic_02_classless_progression`** (should be **zero**); quick click-test of `docs/game-design/overview.md` links in the GitHub preview for the PR.