diff --git a/docs_build/dev/ProjectInstructions/addendums/team_release_readiness.md b/docs_build/dev/ProjectInstructions/addendums/team_release_readiness.md
new file mode 100644
index 000000000..f492806d8
--- /dev/null
+++ b/docs_build/dev/ProjectInstructions/addendums/team_release_readiness.md
@@ -0,0 +1,31 @@
+# Team Release Readiness Gate
+
+## Purpose
+
+This gate prevents Team Alpha, Team Beta, Team Gamma, or Team OWNER from starting regular assigned work before the ProjectInstructions operating system is ready.
+
+## Release Rule
+
+Teams may start only when all of the following are true:
+
+- `docs_build/dev/ProjectInstructions/backlog/BACKLOG_MASTER.md` exists and is populated.
+- `docs_build/dev/ProjectInstructions/team_assignments/TEAM_ASSIGNMENTS.md` exists.
+- OWNER governance exists.
+- One-active-branch-per-team rule exists.
+- No-direct-main rule exists.
+- Out-of-scope stop rule exists.
+- Build Path sync rule exists.
+
+## Gate Outcome
+
+If every requirement is true, team start commands may be issued.
+
+If any requirement is missing, stop and report:
+- missing requirement
+- expected file or rule
+- current branch
+- recommended owner action
+
+## No Silent Starts
+
+Teams must not infer readiness from an incomplete stack. Readiness must be documented before team work begins.
diff --git a/docs_build/dev/reports/PR_26172_OWNER_013-team-release-readiness-gate-instruction-compliance-checklist.md b/docs_build/dev/reports/PR_26172_OWNER_013-team-release-readiness-gate-instruction-compliance-checklist.md
new file mode 100644
index 000000000..c604bc1b9
--- /dev/null
+++ b/docs_build/dev/reports/PR_26172_OWNER_013-team-release-readiness-gate-instruction-compliance-checklist.md
@@ -0,0 +1,12 @@
+# PR_26172_OWNER_013 Instruction Compliance Checklist
+
+- PASS: Read `docs_build/dev/PROJECT_INSTRUCTIONS.md`.
+- PASS: Read `docs_build/dev/PROJECT_MULTI_PC.txt`.
+- PASS: OWNER override is explicitly documented in the request.
+- PASS: Branch name mirrors PR ownership: `pr/26172-OWNER-013-team-release-readiness-gate`.
+- PASS: PR starts from PR012 branch.
+- PASS: Scope stayed focused on `team_release_readiness.md`.
+- PASS: No direct commit to `main`.
+- PASS: No protected ProjectInstructions content was deleted or rewritten.
+- PASS: Required review artifacts are produced.
+- PASS: Required ZIP path is `tmp/PR_26172_OWNER_013-team-release-readiness-gate_delta.zip`.
diff --git a/docs_build/dev/reports/PR_26172_OWNER_013-team-release-readiness-gate-manual-validation-notes.md b/docs_build/dev/reports/PR_26172_OWNER_013-team-release-readiness-gate-manual-validation-notes.md
new file mode 100644
index 000000000..bbbb041d9
--- /dev/null
+++ b/docs_build/dev/reports/PR_26172_OWNER_013-team-release-readiness-gate-manual-validation-notes.md
@@ -0,0 +1,9 @@
+# PR_26172_OWNER_013 Manual Validation Notes
+
+- Confirmed branch was created from PR012 branch.
+- Confirmed `team_release_readiness.md` was added.
+- Confirmed every requested readiness requirement is listed.
+- Confirmed gate failure behavior is documented.
+- Confirmed no protected ProjectInstructions content was deleted or rewritten.
+- Did not run Playwright because this is documentation-only.
+- Did not run samples.
diff --git a/docs_build/dev/reports/PR_26172_OWNER_013-team-release-readiness-gate.md b/docs_build/dev/reports/PR_26172_OWNER_013-team-release-readiness-gate.md
new file mode 100644
index 000000000..a94406e13
--- /dev/null
+++ b/docs_build/dev/reports/PR_26172_OWNER_013-team-release-readiness-gate.md
@@ -0,0 +1,26 @@
+# PR_26172_OWNER_013-team-release-readiness-gate
+
+## Scope
+
+Create the Team Release Readiness Gate addendum on top of PR012.
+
+## Stack Base
+
+Base branch: `pr/26172-OWNER-012-initial-team-assignments`
+
+## Changes
+
+- Added `docs_build/dev/ProjectInstructions/addendums/team_release_readiness.md`.
+- Added release rule requiring populated backlog, team assignments, OWNER governance, one-active-branch-per-team, no-direct-main, out-of-scope stop, and Build Path sync rules.
+- Added stop/report behavior when a readiness requirement is missing.
+
+## Validation
+
+- `git diff --check`
+- Markdown/text review for every requested release-gate requirement.
+- Playwright skipped: no UI/runtime files changed.
+- Samples skipped: not requested.
+
+## ZIP
+
+`tmp/PR_26172_OWNER_013-team-release-readiness-gate_delta.zip`
diff --git a/docs_build/dev/reports/codex_changed_files.txt b/docs_build/dev/reports/codex_changed_files.txt
index 7859a88ae..644c0fa9c 100644
--- a/docs_build/dev/reports/codex_changed_files.txt
+++ b/docs_build/dev/reports/codex_changed_files.txt
@@ -1,6 +1,6 @@
-docs_build/dev/ProjectInstructions/team_assignments/TEAM_ASSIGNMENTS.md
+docs_build/dev/ProjectInstructions/addendums/team_release_readiness.md
 docs_build/dev/reports/codex_changed_files.txt
 docs_build/dev/reports/codex_review.diff
-docs_build/dev/reports/PR_26172_OWNER_012-initial-team-assignments.md
-docs_build/dev/reports/PR_26172_OWNER_012-initial-team-assignments-instruction-compliance-checklist.md
-docs_build/dev/reports/PR_26172_OWNER_012-initial-team-assignments-manual-validation-notes.md
+docs_build/dev/reports/PR_26172_OWNER_013-team-release-readiness-gate.md
+docs_build/dev/reports/PR_26172_OWNER_013-team-release-readiness-gate-instruction-compliance-checklist.md
+docs_build/dev/reports/PR_26172_OWNER_013-team-release-readiness-gate-manual-validation-notes.md
diff --git a/docs_build/dev/reports/codex_review.diff b/docs_build/dev/reports/codex_review.diff
index e822f0236..31b231b3c 100644
--- a/docs_build/dev/reports/codex_review.diff
+++ b/docs_build/dev/reports/codex_review.diff
@@ -1,15 +1,15 @@
 diff --git a/docs_build/dev/reports/codex_changed_files.txt b/docs_build/dev/reports/codex_changed_files.txt
-index 052b24199..7859a88ae 100644
+index 7859a88ae..644c0fa9c 100644
 --- a/docs_build/dev/reports/codex_changed_files.txt
 +++ b/docs_build/dev/reports/codex_changed_files.txt
 @@ -1,6 +1,6 @@
--docs_build/dev/ProjectInstructions/backlog/BACKLOG_MASTER.md
-+docs_build/dev/ProjectInstructions/team_assignments/TEAM_ASSIGNMENTS.md
+-docs_build/dev/ProjectInstructions/team_assignments/TEAM_ASSIGNMENTS.md
++docs_build/dev/ProjectInstructions/addendums/team_release_readiness.md
  docs_build/dev/reports/codex_changed_files.txt
  docs_build/dev/reports/codex_review.diff
--docs_build/dev/reports/PR_26172_OWNER_011-backlog-master-game-journey-population.md
--docs_build/dev/reports/PR_26172_OWNER_011-backlog-master-game-journey-population-instruction-compliance-checklist.md
--docs_build/dev/reports/PR_26172_OWNER_011-backlog-master-game-journey-population-manual-validation-notes.md
-+docs_build/dev/reports/PR_26172_OWNER_012-initial-team-assignments.md
-+docs_build/dev/reports/PR_26172_OWNER_012-initial-team-assignments-instruction-compliance-checklist.md
-+docs_build/dev/reports/PR_26172_OWNER_012-initial-team-assignments-manual-validation-notes.md
+-docs_build/dev/reports/PR_26172_OWNER_012-initial-team-assignments.md
+-docs_build/dev/reports/PR_26172_OWNER_012-initial-team-assignments-instruction-compliance-checklist.md
+-docs_build/dev/reports/PR_26172_OWNER_012-initial-team-assignments-manual-validation-notes.md
++docs_build/dev/reports/PR_26172_OWNER_013-team-release-readiness-gate.md
++docs_build/dev/reports/PR_26172_OWNER_013-team-release-readiness-gate-instruction-compliance-checklist.md
++docs_build/dev/reports/PR_26172_OWNER_013-team-release-readiness-gate-manual-validation-notes.md