diff --git a/scripts/gen_rack.py b/scripts/gen_rack.py
index 9bf9b46..499d162 100644
--- a/scripts/gen_rack.py
+++ b/scripts/gen_rack.py
@@ -120,6 +120,58 @@ def check_overlaps(items: list[dict]) -> None:
                 occupied[key] = name
 
 
+def _pdu_index(items: list[dict]) -> dict[str, dict]:
+    """Map hostname -> frontmatter for every kind:pdu item."""
+    return {
+        fm.get("hostname"): fm
+        for fm in items
+        if fm.get("kind") == "pdu"
+    }
+
+
+def validate_power(items: list[dict]) -> None:
+    """Validate PDU outlet declarations and `power` feeds within one rack.
+
+    Rule 3: every power[].pdu resolves to a kind:pdu file, and outlet is
+    within that PDU's `outlets` count.
+    """
+    pdus = _pdu_index(items)
+    for name, fm in pdus.items():
+        outlets = fm.get("outlets")
+        if not isinstance(outlets, int) or outlets < 1:
+            raise SchemaError(
+                f"{name}: kind:pdu must declare a positive integer 'outlets'"
+            )
+    for fm in items:
+        feeds = fm.get("power")
+        if feeds is None:
+            continue
+        name = fm.get("hostname", "?")
+        if not isinstance(feeds, list):
+            raise SchemaError(f"{name}: power must be a list")
+        for feed in feeds:
+            if not isinstance(feed, dict):
+                raise SchemaError(f"{name}: power entry must be a mapping")
+            pdu = feed.get("pdu")
+            outlet = feed.get("outlet")
+            if not isinstance(pdu, str) or not pdu:
+                raise SchemaError(f"{name}: power entry needs a non-empty 'pdu'")
+            if not isinstance(outlet, int):
+                raise SchemaError(
+                    f"{name}: power entry for {pdu} needs an integer 'outlet'"
+                )
+            target = pdus.get(pdu)
+            if target is None:
+                raise SchemaError(
+                    f"{name}: power pdu={pdu!r} is not a known kind:pdu file"
+                )
+            count = target["outlets"]
+            if outlet < 1 or outlet > count:
+                raise SchemaError(
+                    f"{name}: outlet {outlet} out of range 1..{count} on {pdu}"
+                )
+
+
 def _esc(s: object) -> str:
     return str(s).replace("&", "&amp;").replace("<", "&lt;").replace(">", "&gt;")
 
@@ -295,6 +347,7 @@ def generate(hardware_dir: Path, output_dir: Path) -> int:
         for rack, ritems in racks.items():
             try:
                 check_overlaps(ritems)
+                validate_power(ritems)
             except SchemaError as e:
                 errors.append(f"{rack}: {e}")
 
diff --git a/tests/test_gen_rack.py b/tests/test_gen_rack.py
index c056d2e..875c3a4 100644
--- a/tests/test_gen_rack.py
+++ b/tests/test_gen_rack.py
@@ -192,3 +192,86 @@ def test_generate_returns_1_on_overlap(tmp_path):
 
     assert rc == 1
     assert not (out / "rack01.md").exists()
+
+
+def test_validate_power_accepts_valid_feed():
+    items = [
+        item(hostname="pdu01", kind="pdu", rack_face="left", outlets=8),
+        item(hostname="mf00", rack_u=1, u_height=1, rack_face="front",
+             power=[{"pdu": "pdu01", "outlet": 1}]),
+    ]
+    gen_rack.validate_power(items)
+
+
+def test_validate_power_rejects_unknown_pdu():
+    items = [item(hostname="mf00", rack_u=1, u_height=1, rack_face="front",
+                  power=[{"pdu": "ghost", "outlet": 1}])]
+    with pytest.raises(gen_rack.SchemaError):
+        gen_rack.validate_power(items)
+
+
+def test_validate_power_rejects_non_pdu_target():
+    items = [
+        item(hostname="sw01", kind="switch", rack_u=1, u_height=1,
+             rack_face="front"),
+        item(hostname="mf00", rack_u=2, u_height=1, rack_face="front",
+             power=[{"pdu": "sw01", "outlet": 1}]),
+    ]
+    with pytest.raises(gen_rack.SchemaError):
+        gen_rack.validate_power(items)
+
+
+def test_validate_power_rejects_outlet_over_count():
+    items = [
+        item(hostname="pdu01", kind="pdu", rack_face="left", outlets=8),
+        item(hostname="mf00", rack_u=1, u_height=1, rack_face="front",
+             power=[{"pdu": "pdu01", "outlet": 9}]),
+    ]
+    with pytest.raises(gen_rack.SchemaError):
+        gen_rack.validate_power(items)
+
+
+def test_validate_power_rejects_outlet_zero():
+    items = [
+        item(hostname="pdu01", kind="pdu", rack_face="left", outlets=8),
+        item(hostname="mf00", rack_u=1, u_height=1, rack_face="front",
+             power=[{"pdu": "pdu01", "outlet": 0}]),
+    ]
+    with pytest.raises(gen_rack.SchemaError):
+        gen_rack.validate_power(items)
+
+
+def test_validate_power_rejects_malformed_entry():
+    items = [
+        item(hostname="pdu01", kind="pdu", rack_face="left", outlets=8),
+        item(hostname="mf00", rack_u=1, u_height=1, rack_face="front",
+             power=["pdu01"]),
+    ]
+    with pytest.raises(gen_rack.SchemaError):
+        gen_rack.validate_power(items)
+
+
+def test_validate_power_rejects_pdu_without_outlets():
+    items = [
+        item(hostname="pdu01", kind="pdu", rack_face="left"),
+        item(hostname="mf00", rack_u=1, u_height=1, rack_face="front",
+             power=[{"pdu": "pdu01", "outlet": 1}]),
+    ]
+    with pytest.raises(gen_rack.SchemaError):
+        gen_rack.validate_power(items)
+
+
+def test_generate_returns_1_on_bad_power_ref(tmp_path):
+    hw = tmp_path / "hardware"
+    out = tmp_path / "out"
+    hw.mkdir()
+    _write_item(
+        hw,
+        "mf00",
+        "---\nhostname: mf00\nkind: server\nstatus: in-use\n"
+        "rack: rack01\nrack_u: 1\nu_height: 1\nrack_face: front\n"
+        "power:\n  - { pdu: ghost, outlet: 1 }\n---\n",
+    )
+    rc = gen_rack.generate(hw, out)
+    assert rc == 1
+    assert not (out / "rack01.md").exists()