diff --git a/test_swarmmetrics.py b/test_swarmmetrics.py
index b2f1eca..a45d04f 100644
--- a/test_swarmmetrics.py
+++ b/test_swarmmetrics.py
@@ -218,6 +218,103 @@ def test_f33_gibberish_high_score():
     # The formula chain is an anti-spam filter, not a quality metric.
 
 
+def test_f33_adversarial_synonym_padding():
+    """F3.3-aware adversary: one unique concept per message inflates score.
+    Test for AX-7 (Colony): 'Do your tests include an adversary who has read F3.3?'
+    Answer: now they do.
+
+    Attack: adversary reads F3.3 source, sees log(unique_concepts) is the lever.
+    Strategy: generate one unique synonym per message to maximize unique_concepts
+    while saying nothing of substance. 50 messages, 50 'unique' concepts, all
+    semantically equivalent to 'hello'.
+
+    Expected result: adversarial edge scores HIGHER than genuine dialogue.
+    This is a known gap — F3.3 treats string-distinct as concept-distinct.
+    Closing this requires embedding-based deduplication (F3.4 roadmap)."""
+    msgs = []
+    # Genuine dialogue: 5 messages, 7 unique concepts, high reciprocity
+    genuine = [
+        {"from_id": "alice", "to_id": "bob", "timestamp": now - 1*day,
+         "concepts": ["graph-theory", "reciprocity"]},
+        {"from_id": "bob", "to_id": "alice", "timestamp": now - 0.9*day,
+         "concepts": ["decay", "half-life"]},
+        {"from_id": "alice", "to_id": "bob", "timestamp": now - 0.8*day,
+         "concepts": ["echo-coefficient"]},
+        {"from_id": "bob", "to_id": "alice", "timestamp": now - 0.7*day,
+         "concepts": ["shadow-detection", "gini"]},
+    ]
+    msgs.extend(genuine)
+
+    # Adversary who has read F3.3: 50 msgs, each with a unique synonym of "hello"
+    # Balanced reciprocity (25+25) to maximize log(1+r)
+    hello_synonyms = [f"greeting-{i}" for i in range(50)]
+    for i in range(25):
+        msgs.append({"from_id": "eve", "to_id": "mallory",
+                     "timestamp": now - 2*day + i*60,
+                     "concepts": [hello_synonyms[i], hello_synonyms[i+25]]})
+    for i in range(25):
+        msgs.append({"from_id": "mallory", "to_id": "eve",
+                     "timestamp": now - 1.5*day + i*60,
+                     "concepts": [hello_synonyms[25+i]]})
+
+    edges = score_reciprocity(msgs, now=now)
+    genuine_edge = [e for e in edges.values() if "alice" in (e.source, e.target)][0]
+    adversarial_edge = [e for e in edges.values() if "eve" in (e.source, e.target)][0]
+
+    # The adversary WINS on F3.3 — this is the documented gap
+    assert adversarial_edge.reciprocity_f33 > genuine_edge.reciprocity_f33, \
+        (f"Expected adversary to beat genuine on F3.3 (known gap): "
+         f"adv={adversarial_edge.reciprocity_f33:.4f} vs gen={genuine_edge.reciprocity_f33:.4f}")
+    # Document the ratio for future F3.4 comparison
+    gap_ratio = adversarial_edge.reciprocity_f33 / max(genuine_edge.reciprocity_f33, 0.001)
+    assert gap_ratio > 1.5, \
+        f"Adversary should win by significant margin (gap_ratio={gap_ratio:.1f})"
+
+
+def test_f33_adversarial_defeated_by_echo():
+    """Full stack test: F3.3-aware adversary is caught by causal echo.
+    The adversary beats F3.3 alone but their concepts have zero echo
+    because no third party adopts 'greeting-17' independently.
+
+    This proves the stack (F3.3 + echo) catches what each layer alone misses."""
+    msgs = []
+    # Adversary pair: high F3.3, zero echo (concepts never appear elsewhere)
+    for i in range(10):
+        msgs.append({"from_id": "eve", "to_id": "mallory",
+                     "timestamp": now - 2*day + i*100,
+                     "concepts": [f"adversarial-concept-{i}"]})
+    for i in range(10):
+        msgs.append({"from_id": "mallory", "to_id": "eve",
+                     "timestamp": now - 1.5*day + i*100,
+                     "concepts": [f"adversarial-concept-{10+i}"]})
+
+    # Genuine pair: moderate F3.3, positive echo (concepts adopted by third party)
+    msgs.append({"from_id": "alice", "to_id": "bob",
+                 "timestamp": now - 3*day, "concepts": ["reciprocity"]})
+    msgs.append({"from_id": "bob", "to_id": "alice",
+                 "timestamp": now - 2.5*day, "concepts": ["reciprocity", "decay"]})
+    # Third party uses the same concept AFTER exposure
+    msgs.append({"from_id": "charlie", "to_id": "dave",
+                 "timestamp": now - 1*day, "concepts": ["reciprocity"]})
+
+    # F3.3: adversary wins
+    edges = score_reciprocity(msgs, now=now)
+    adv = [e for e in edges.values() if "eve" in (e.source, e.target)][0]
+    gen = [e for e in edges.values() if "alice" in (e.source, e.target)][0]
+    assert adv.reciprocity_f33 > gen.reciprocity_f33, \
+        "Adversary should beat genuine on F3.3 alone"
+
+    # Echo: genuine wins (concept adopted by charlie)
+    echo = score_echo(msgs)
+    alice_echo = echo.get("alice", 0)
+    eve_echo = echo.get("eve", 0)
+    assert alice_echo > eve_echo, \
+        f"Genuine should beat adversary on echo: alice={alice_echo}, eve={eve_echo}"
+    # Eve's adversarial concepts should have zero echo
+    assert eve_echo == 0, \
+        f"Adversary concepts should have zero echo: {eve_echo}"
+
+
 # Run all tests
 tests = [v for k, v in sorted(globals().items()) if k.startswith("test_")]
 passed = 0