diff --git a/Assets/Scripts/ServerShared/ZoneData.cs b/Assets/Scripts/ServerShared/ZoneData.cs
index 634b6f9cc..890b2dfef 100644
--- a/Assets/Scripts/ServerShared/ZoneData.cs
+++ b/Assets/Scripts/ServerShared/ZoneData.cs
@@ -226,8 +226,9 @@ public static class FieldKinds
             .Select(kind =>
             {
                 var key = catalog.RefOf(kind).Key;
-                return (Key: key, Weight: kind.GenerationWeight * Factor(
-                    type?.Kinds.Where(entry => entry.Kind.Key.Equals(key)).Select(entry => (double) entry.Weight), 1.0));
+                var factor = Factor(type?.Kinds.Where(entry => entry.Kind.Key.Equals(key)).Select(entry => (double) entry.Weight), 1.0);
+                // Both must be positive: two negatives do not multiply into a weight.
+                return (Key: key, Weight: kind.GenerationWeight > 0f && factor > 0.0 ? kind.GenerationWeight * factor : 0.0);
             })
             .Where(kind => kind.Weight > 0.0)
             .OrderBy(kind => kind.Key.Value, StringComparer.Ordinal)
diff --git a/tests/Aetheria.Shared.Tests/OreGeographyTests.cs b/tests/Aetheria.Shared.Tests/OreGeographyTests.cs
index 2b4097322..582b5d65e 100644
--- a/tests/Aetheria.Shared.Tests/OreGeographyTests.cs
+++ b/tests/Aetheria.Shared.Tests/OreGeographyTests.cs
@@ -238,6 +238,25 @@ public sealed class OreGeographyTests : IDisposable
         Assert.False(FieldKinds.Assign("belt-0", Empty(), default).IsSet());
     }
 
+    [Fact]
+    public void AKindWhoseCombinedWeightIsNotPositiveIsNeverDrawn()
+    {
+        var cache = Empty();
+        var negative = Kind(cache, "negative", -1f);
+        Kind(cache, "positive", 1f);
+        var flipped = Province(cache, "flipped", 1, new[] {KindFactor(negative, -1f)});
+        for (var i = 0; i < 500; i++)
+        {
+            Assert.Equal("field-kind:positive", FieldKinds.Assign($"belt-{i}", cache, default).Key.Value);
+            Assert.Equal("field-kind:positive", FieldKinds.Assign($"belt-{i}", cache, flipped).Key.Value);
+        }
+
+        // With nothing positive left the belt has no kind, rather than the negative one.
+        var only = Empty();
+        var lone = Kind(only, "negative", -1f);
+        Assert.False(FieldKinds.Assign("belt-0", only, Province(only, "flipped", 1, new[] {KindFactor(lone, -1f)})).IsSet());
+    }
+
     [Fact]
     public void ProvinceWeightsTheKindDraw()
     {