diff --git a/src/mudlib/combat/encounter.py b/src/mudlib/combat/encounter.py
index 93b82d4..071990d 100644
--- a/src/mudlib/combat/encounter.py
+++ b/src/mudlib/combat/encounter.py
@@ -123,6 +123,23 @@ class CombatEncounter:
                 combat_ended=False,
             )
 
+        # Check for altitude mismatch (flying dodge)
+        attacker_flying = getattr(self.attacker, "flying", False)
+        defender_flying = getattr(self.defender, "flying", False)
+        if attacker_flying != defender_flying:
+            # Altitude mismatch - attack misses
+            template = "{attacker}'s attack miss{es} — {defender} {is|is} out of reach!"
+            # Reset to IDLE
+            self.state = CombatState.IDLE
+            self.current_move = None
+            self.pending_defense = None
+            return ResolveResult(
+                resolve_template=template,
+                damage=0.0,
+                countered=True,
+                combat_ended=False,
+            )
+
         # Check if defense counters attack
         defense_succeeds = (
             self.pending_defense