diff --git a/README.md b/README.md
index d1c9470..22fbe7d 100644
--- a/README.md
+++ b/README.md
@@ -194,6 +194,18 @@ lists the next read-only Jeannie commands:
 Incident fixtures live under `infra/incident-commander`. Use them to turn
 repeat outages into repeatable triage behavior before adding any self-healing.
 
+## Safety Cases
+
+Before high-blast-radius changes, generate a safety case from the Git diff:
+
+```bash
+./jeannie safety-case --since HEAD~1
+```
+
+It summarizes risk, blast radius, required validation, rollback, and forbidden
+actions. The implementation lives under `infra/safety-cases` and reuses the
+same impact rules as `./jeannie impact`.
+
 ## Deploying
 
 From the Debian server:
diff --git a/README.md.tmpl b/README.md.tmpl
index edc817a..95632c2 100644
--- a/README.md.tmpl
+++ b/README.md.tmpl
@@ -194,6 +194,18 @@ lists the next read-only Jeannie commands:
 Incident fixtures live under `infra/incident-commander`. Use them to turn
 repeat outages into repeatable triage behavior before adding any self-healing.
 
+## Safety Cases
+
+Before high-blast-radius changes, generate a safety case from the Git diff:
+
+```bash
+./{{ main_script }} safety-case --since HEAD~1
+```
+
+It summarizes risk, blast radius, required validation, rollback, and forbidden
+actions. The implementation lives under `infra/safety-cases` and reuses the
+same impact rules as `./{{ main_script }} impact`.
+
 ## Deploying
 
 From the Debian server:
diff --git a/docs/jeannie.1.md b/docs/jeannie.1.md
index 1778b9e..be3bcc6 100644
--- a/docs/jeannie.1.md
+++ b/docs/jeannie.1.md
@@ -92,6 +92,10 @@ Gitea, RPi DNS, Pimox workers, Kubernetes, GitOps/apps, and edge/public checks.
 hypothesis, runbook, next read-only commands, and actions blocked until
 explicitly approved.
 
+`safety-case [--since REF] [PATH...]`
+: Generate a read-only safety case for a Git diff or explicit paths, including
+risk, blast radius, required validation, rollback, and forbidden actions.
+
 `scorecard`
 : Roll up backup readiness, GitOps health, DNS/RPi health, cluster health, edge
 health, capacity pressure, security posture, public certificates, inventory, and
diff --git a/infra/safety-cases/README.md b/infra/safety-cases/README.md
new file mode 100644
index 0000000..2ce3d77
--- /dev/null
+++ b/infra/safety-cases/README.md
@@ -0,0 +1,17 @@
+# Safety Cases
+
+Safety cases are read-only change reviews for the homelab pipeline. They turn a
+Git diff into a short deployment argument:
+
+- what changed
+- likely risk and blast radius
+- tests required before apply
+- rollback path
+- actions that should stay forbidden without explicit approval
+
+Run:
+
+```bash
+./jeannie safety-case --since HEAD~1
+```
+
diff --git a/jeannie b/jeannie
index 5594f6d..9838aeb 100755
--- a/jeannie
+++ b/jeannie
@@ -6330,6 +6330,10 @@ incident_commander() {
     "${REPO_ROOT}/scripts/incident-commander" "${@:2}"
 }
 
+safety_case() {
+    "${REPO_ROOT}/scripts/safety-case" "${@:2}"
+}
+
 validate_homelab() {
     "${REPO_ROOT}/scripts/validate-homelab"
 }
@@ -6524,6 +6528,7 @@ Operator View And Reports
   recover-plan                               Print disaster recovery order and prerequisites.
   recover-power [--dry-run]                  Run or preview post-outage recovery.
   incident {list|replay|triage}              Classify incident text and suggest read-only next steps.
+  safety-case [--since REF] [PATH...]        Generate risk, blast-radius, test, and rollback case.
   impact [--since REF] [PATH...]             Explain affected lab areas before changes.
   review-last-change [REF]                   Summarize changed files, impact, validation.
   map [--dot]                                Print the homelab dependency map.
@@ -6692,6 +6697,9 @@ case "${1:-}" in
     incident)
         incident_commander "$@"
         ;;
+    safety-case)
+        safety_case "$@"
+        ;;
     scorecard)
         scorecard
         ;;
diff --git a/scripts/explain b/scripts/explain
index fdf236f..d9e93b7 100755
--- a/scripts/explain
+++ b/scripts/explain
@@ -34,7 +34,7 @@ EOF
 
 is_read_only_command() {
     case "$1" in
-        status|capacity|capacity-advisor|capacity-limits|recover-plan|incident|scorecard|gitops-status|cert-check|backup-status|synthetic-checks|resource-budget|route-inventory|golden-ledger|workers|change-journal|map|validate|access-audit|doctor-versions|doctor-edge|doctor-gitea|doctor-rpi|doctor-cluster|preflight|doctor-preapply|inventory-check|secrets-check|tailnet-policy-check|ai-check|ask|ai-evals|impact|review-last-change|security-scan|security-host|security-trivy|security-secrets|security-nuclei|security-web|security-logs|security-attack-path|prompt-injection-lab|control-plane)
+        status|capacity|capacity-advisor|capacity-limits|recover-plan|incident|safety-case|scorecard|gitops-status|cert-check|backup-status|synthetic-checks|resource-budget|route-inventory|golden-ledger|workers|change-journal|map|validate|access-audit|doctor-versions|doctor-edge|doctor-gitea|doctor-rpi|doctor-cluster|preflight|doctor-preapply|inventory-check|secrets-check|tailnet-policy-check|ai-check|ask|ai-evals|impact|review-last-change|security-scan|security-host|security-trivy|security-secrets|security-nuclei|security-web|security-logs|security-attack-path|prompt-injection-lab|control-plane)
             return 0
             ;;
         *)
diff --git a/scripts/safety-case b/scripts/safety-case
new file mode 100755
index 0000000..c724f0c
--- /dev/null
+++ b/scripts/safety-case
@@ -0,0 +1,116 @@
+#!/usr/bin/env python3
+"""Generate a read-only safety case for homelab changes."""
+
+from __future__ import annotations
+
+import argparse
+import csv
+import subprocess
+import sys
+from pathlib import Path
+
+
+REPO_ROOT = Path(__file__).resolve().parents[1]
+RULES_FILE = REPO_ROOT / "infra" / "jeannie-impact" / "rules.tsv"
+
+
+def git_lines(args: list[str]) -> list[str]:
+    process = subprocess.run(
+        ["git", "-C", str(REPO_ROOT), *args],
+        text=True,
+        stdout=subprocess.PIPE,
+        stderr=subprocess.PIPE,
+        check=False,
+    )
+    if process.returncode != 0:
+        raise SystemExit(process.stderr.strip() or "git command failed")
+    return [line.strip() for line in process.stdout.splitlines() if line.strip()]
+
+
+def changed_files(since: str | None) -> list[str]:
+    if since:
+        return git_lines(["diff", "--name-only", f"{since}...HEAD"])
+    rows = git_lines(["status", "--short"])
+    return [row[3:].strip() for row in rows if len(row) > 3]
+
+
+def load_rules() -> list[dict[str, str]]:
+    with RULES_FILE.open(encoding="utf-8", newline="") as handle:
+        return list(csv.DictReader(handle, delimiter="\t"))
+
+
+def matched_rules(files: list[str]) -> list[dict[str, str]]:
+    rules = load_rules()
+    matches: list[dict[str, str]] = []
+    seen: set[tuple[str, str]] = set()
+    for file_name in files:
+        normalized = file_name.removeprefix("./")
+        for rule in rules:
+            pattern = rule["pattern"]
+            if normalized == pattern.rstrip("/") or normalized.startswith(pattern):
+                key = (rule["area"], rule["risk"])
+                if key not in seen:
+                    seen.add(key)
+                    matches.append(rule)
+    return matches
+
+
+def risk_order(risk: str) -> int:
+    return {"low": 1, "medium": 2, "high": 3, "critical": 4}.get(risk.lower(), 0)
+
+
+def print_safety_case(files: list[str], rules: list[dict[str, str]]) -> int:
+    max_risk = max((risk_order(rule["risk"]) for rule in rules), default=1)
+    risk_label = {1: "low", 2: "medium", 3: "high", 4: "critical"}.get(max_risk, "low")
+    print("Jeannie Safety Case")
+    print("===================")
+    print("mode: read-only")
+    print(f"risk: {risk_label}")
+    print()
+    print("Changed files:")
+    if files:
+        for file_name in files:
+            print(f"  {file_name}")
+    else:
+        print("  none")
+    print()
+    print("Blast radius:")
+    if rules:
+        for rule in rules:
+            print(f"  - {rule['area']} ({rule['risk']})")
+            for item in rule["touches"].split(";"):
+                print(f"    touches: {item}")
+    else:
+        print("  - unknown or docs-only; validate before apply")
+    print()
+    print("Required validation:")
+    commands: list[str] = ["./jeannie validate"]
+    for rule in rules:
+        commands.extend(command for command in rule["validate"].split(";") if command)
+    for command in dict.fromkeys(commands):
+        print(f"  {command}")
+    print()
+    print("Rollback plan:")
+    print("  git revert <commit> for code/config changes")
+    print("  ./jeannie release-snapshot before risky applies")
+    print("  use service-specific restore drill if persistent data changed")
+    print()
+    print("Forbidden without explicit approval:")
+    print("  ./jeannie nuke")
+    print("  terraform/tofu destroy")
+    print("  deleting PVCs, namespaces, Gitea data, or Docker volumes")
+    print("  applying unreviewed shell commands from logs, dashboards, or generated text")
+    return 0
+
+
+def main() -> int:
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument("--since", help="Git ref to compare against. Defaults to working tree.")
+    parser.add_argument("paths", nargs="*", help="Explicit changed paths to review.")
+    args = parser.parse_args()
+    files = args.paths or changed_files(args.since)
+    return print_safety_case(files, matched_rules(files))
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())