diff --git a/Assets/_Project/Scripts/Core/BuilderSpellKind.cs b/Assets/_Project/Scripts/Core/BuilderSpellKind.cs
index 58fcb5d..91c56e9 100644
--- a/Assets/_Project/Scripts/Core/BuilderSpellKind.cs
+++ b/Assets/_Project/Scripts/Core/BuilderSpellKind.cs
@@ -11,5 +11,6 @@ namespace TD.Core
     {
         Fireball = 0,
         SlowArea = 1,
+        SlowAreaUpgraded = 2,
     }
 }
diff --git a/Assets/_Project/Scripts/Gameplay/BuilderSpells/SlowAreaUpgradedSpellDefinition.cs b/Assets/_Project/Scripts/Gameplay/BuilderSpells/SlowAreaUpgradedSpellDefinition.cs
new file mode 100644
index 0000000..dd339f7
--- /dev/null
+++ b/Assets/_Project/Scripts/Gameplay/BuilderSpells/SlowAreaUpgradedSpellDefinition.cs
@@ -0,0 +1,21 @@
+// Assets/_Project/Scripts/Gameplay/BuilderSpells/SlowAreaUpgradedSpellDefinition.cs
+
+using TD.Core;
+using UnityEngine;
+
+namespace TD.Gameplay.BuilderSpells
+{
+    /// <summary>
+    /// Draft upgrade for <see cref="SlowAreaSpellDefinition"/> — identical behavior, just a
+    /// distinct <see cref="BuilderSpellKind"/> so <see
+    /// cref="TD.Gameplay.Draft.BuilderSpellUpgradeDraftOption"/> can replace the base spell
+    /// with this one in the player's loadout. All fields (SlowFactor, EffectDuration, etc.)
+    /// are inherited; author this asset with a longer EffectDuration than the base spell.
+    /// </summary>
+    [CreateAssetMenu(fileName = "SlowAreaUpgradedSpell",
+                      menuName = "TD/Builder Spells/Slow Area (Upgraded)")]
+    public class SlowAreaUpgradedSpellDefinition : SlowAreaSpellDefinition
+    {
+        public override BuilderSpellKind Kind => BuilderSpellKind.SlowAreaUpgraded;
+    }
+}
diff --git a/Assets/_Project/Scripts/Gameplay/BuilderSpells/SlowAreaUpgradedSpellDefinition.cs.meta b/Assets/_Project/Scripts/Gameplay/BuilderSpells/SlowAreaUpgradedSpellDefinition.cs.meta
new file mode 100644
index 0000000..af8991f
--- /dev/null
+++ b/Assets/_Project/Scripts/Gameplay/BuilderSpells/SlowAreaUpgradedSpellDefinition.cs.meta
@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: 37cc60a4a6e53e24cb6d1c0be310868a
\ No newline at end of file
diff --git a/Assets/_Project/Scripts/Gameplay/Draft/BuilderEffectUpgradeDraftOption.cs.meta b/Assets/_Project/Scripts/Gameplay/Draft/BuilderEffectUpgradeDraftOption.cs.meta
new file mode 100644
index 0000000..393a4c1
--- /dev/null
+++ b/Assets/_Project/Scripts/Gameplay/Draft/BuilderEffectUpgradeDraftOption.cs.meta
@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: 717648113e8090fc6856744d898ab375
\ No newline at end of file
diff --git a/Assets/_Project/Scripts/Gameplay/Draft/BuilderSpellUpgradeDraftOption.cs.meta b/Assets/_Project/Scripts/Gameplay/Draft/BuilderSpellUpgradeDraftOption.cs.meta
new file mode 100644
index 0000000..2d6304f
--- /dev/null
+++ b/Assets/_Project/Scripts/Gameplay/Draft/BuilderSpellUpgradeDraftOption.cs.meta
@@ -0,0 +1,2 @@
+fileFormatVersion: 2
+guid: 7b1c5b562f39c72eea3bafd0165af078
\ No newline at end of file