diff --git a/Assets/Scripts/ServerShared/Loadout.cs b/Assets/Scripts/ServerShared/Loadout.cs
index 15e832a58..b8b73a0ab 100644
--- a/Assets/Scripts/ServerShared/Loadout.cs
+++ b/Assets/Scripts/ServerShared/Loadout.cs
@@ -96,19 +96,28 @@ public static class Loadouts
         _ => ""
     };
 
-    // The only writer of Loadout records. It opens its own short-lived cache over the catalog file, writable, and disposes it
-    // after the one commit. No other cache is touched, so no catalog instance play holds (or has mutated) can reach the
-    // file; a cache that already has the catalog open sees the loadout only once it reloads.
-    // The catalog is a stack of packages, the shipped content included (ruling catalog-is-a-package-stack), so a loadout may
-    // name any design the stack holds; one whose package is later removed fails closed where it is built, with its reason logged.
-    // Throws and writes nothing when the file is missing (capture never creates a catalog), when a loadout of this name
-    // exists under another key, or when one exists under KeyOf(Name) and replace is not set. The commit is conditional
-    // on the record at KeyOf(Name), so a loadout changed on disk since this open is not clobbered: returns false then.
-    public static bool Commit(string catalogPath, Loadout loadout, bool replace)
+    // The only writer of Loadout records, and of the Faction.BossLoadout that names one. It opens its own short-lived cache
+    // over the catalog file, writable, and disposes it after the one commit. No other cache is touched, so no catalog
+    // instance play holds (or has mutated) can reach the file; a cache that already has the catalog open sees the loadout
+    // only once it reloads. The catalog is a stack of packages, the shipped content included (ruling
+    // catalog-is-a-package-stack), so a loadout may name any design the stack holds; one whose package is later removed fails
+    // closed where it is built, with its reason logged. With bossOf set, the same batch makes the loadout that faction's boss
+    // (Faction.BossLoadout), so the loadout and the reference land together or not at all.
+    // Throws and writes nothing when the file is missing (capture never creates a catalog), when bossOf names no faction in
+    // it, when a loadout of this name exists under another key, or when one exists under KeyOf(Name) and replace is not set.
+    // The commit is conditional on the record at KeyOf(Name) and on the faction, so a record changed on disk since this open
+    // is not clobbered: returns false then, and neither is written.
+    public static bool Commit(string catalogPath, Loadout loadout, bool replace, CultRecordRef<Faction> bossOf = default)
     {
         if (!File.Exists(catalogPath))
             throw new InvalidOperationException($"Catalog {catalogPath} does not exist; a loadout commit never creates one.");
         using var cache = AetheriaStores.Open(catalogPath, catalogWritable: true);
+        return Commit(cache, loadout, replace, bossOf);
+    }
+
+    // The one batch Commit(path, ...) makes, over a writable catalog cache the caller opened.
+    internal static bool Commit(CultCache cache, Loadout loadout, bool replace, CultRecordRef<Faction> bossOf)
+    {
         var key = KeyOf(loadout.Name);
         var namesake = cache.GetAll<Loadout>().FirstOrDefault(other => other.Name == loadout.Name && !cache.RefOf(other).Key.Equals(key));
         if (namesake != null)
@@ -116,10 +125,17 @@ public static class Loadouts
         var existing = cache.Get<Loadout>(key);
         if (existing != null && !replace)
             throw new InvalidOperationException($"Loadout '{loadout.Name}' already exists; replace it explicitly.");
+        var boss = bossOf.IsSet()
+            ? cache.Get(bossOf) ?? throw new InvalidOperationException($"Loadout '{loadout.Name}': the boss faction is not in the catalog.")
+            : null;
         return cache.Commit(batch =>
         {
             batch.Expect(key, existing);
             batch.Upsert(typeof(Loadout), loadout, key);
+            if (boss == null) return;
+            batch.Expect(bossOf.Key, boss);
+            boss.BossLoadout = new CultRecordRef<Loadout>(key);
+            batch.Upsert(boss.GetType(), boss, bossOf.Key);
         });
     }
 
diff --git a/tests/Aetheria.Shared.Tests/LoadoutTests.cs b/tests/Aetheria.Shared.Tests/LoadoutTests.cs
index c073bf37e..6f55baa76 100644
--- a/tests/Aetheria.Shared.Tests/LoadoutTests.cs
+++ b/tests/Aetheria.Shared.Tests/LoadoutTests.cs
@@ -143,6 +143,73 @@ public sealed class LoadoutTests : IDisposable
         Assert.Equal(key, (where == "hull" ? written.Hull.Key : written.Slots[1].Design.Key).Value);
     }
 
+    // With bossOf, one commit writes the loadout and makes it that faction's boss: Faction.BossLoadout names its key.
+    [Fact]
+    public void ABossCommitWritesTheLoadoutAndTheFactionsBossReference()
+    {
+        using (var cache = Open())
+            Assert.True(Loadouts.Commit(Catalog, HandBuilt(cache), replace: false, cache.RefOf(cache.GetByName<Faction>("Maker"))));
+
+        using (var cache = Open())
+        {
+            var loadout = Assert.Single(cache.GetAll<Loadout>());
+            Assert.Equal(Loadouts.KeyOf("Skiff build"), cache.RefOf(loadout).Key);
+            Assert.Same(loadout, Loadouts.BossOf(cache, cache.GetByName<Faction>("Maker"), out var refusal));
+            Assert.Equal(BossRefusal.None, refusal);
+        }
+    }
+
+    // The loadout and the boss reference are one batch: when the faction changed on disk after the commit's cache read it,
+    // the commit returns false and neither lands, though the loadout alone would have; the other writer's change survives.
+    [Fact]
+    public void ABossCommitOverAFactionChangedOnDiskWritesNeitherTheLoadoutNorTheReference()
+    {
+        Loadout loadout;
+        CultRecordRef<Faction> maker;
+        using (var read = Open())
+        {
+            loadout = HandBuilt(read);
+            maker = read.RefOf(read.GetByName<Faction>("Maker"));
+        }
+
+        using (var stale = AetheriaStores.Open(Catalog, catalogWritable: true))
+        {
+            Assert.NotNull(stale.Get(maker));
+            using (var other = AetheriaStores.Open(Catalog, catalogWritable: true))
+            {
+                var fresh = other.Get(maker);
+                Assert.True(other.Commit(batch =>
+                {
+                    batch.Expect(maker.Key, fresh);
+                    fresh.ShortName = "NEW";
+                    batch.Upsert(typeof(Faction), fresh, maker.Key);
+                }));
+            }
+
+            Assert.False(Loadouts.Commit(stale, loadout, replace: false, maker));
+        }
+
+        using var after = Open();
+        Assert.Empty(after.GetAll<Loadout>());
+        var faction = after.Get(maker);
+        Assert.Equal("NEW", faction.ShortName);
+        Assert.False(faction.BossLoadout.IsSet());
+    }
+
+    // A boss faction the catalog does not hold is refused before anything is written.
+    [Fact]
+    public void ABossCommitNamingNoFactionIsRefusedAndNothingIsWritten()
+    {
+        var before = Hash(Catalog);
+        using (var cache = Open())
+        {
+            var error = Assert.Throws<InvalidOperationException>(() =>
+                Loadouts.Commit(Catalog, HandBuilt(cache), replace: false, new CultRecordRef<Faction>(new CultRecordKey("faction:absent"))));
+            Assert.Contains("boss faction is not in the catalog", error.Message);
+        }
+        Assert.Equal(before, Hash(Catalog));
+    }
+
     // Recapturing a name refuses without replace and leaves the file untouched; with replace it replaces, never duplicates.
     [Fact]
     public void SameNameCaptureReplacesOnlyWhenAsked()