diff --git a/Projects/Server/Interfaces.cs b/Projects/Server/Interfaces.cs
index 8638e4fc7..7ffbd9596 100644
--- a/Projects/Server/Interfaces.cs
+++ b/Projects/Server/Interfaces.cs
@@ -35,7 +35,7 @@ public interface ISpell
 {
     bool BlocksMovement { get; }
     bool IsCasting { get; }
-    void OnCasterHurt();
+    void OnCasterHurt(DamageType damageType = DamageType.None);
     void OnCasterKilled();
     void OnConnectionChanged();
     bool OnCasterMoving(Direction d);
diff --git a/Projects/Server/Mobiles/Mobile.cs b/Projects/Server/Mobiles/Mobile.cs
index 778d5b5a7..a3497f163 100644
--- a/Projects/Server/Mobiles/Mobile.cs
+++ b/Projects/Server/Mobiles/Mobile.cs
@@ -151,6 +151,16 @@ public enum VisibleDamageType
     Selective
 }
 
+public enum DamageType
+{
+    None,
+    Physical,
+    Fire,
+    Cold,
+    Poison,
+    Energy
+}
+
 public enum ResistanceType
 {
     Physical,
@@ -339,6 +349,7 @@ public partial class Mobile : IHued, IComparable<Mobile>, ISpawnable, IObjectPro
 
     private int m_SolidHueOverride = -1;
     private ISpell m_Spell;
+    private DamageType _damageType;
     private int m_StatCap;
     private int m_Str, m_Dex, m_Int;
 
@@ -5919,6 +5930,21 @@ public partial class Mobile : IHued, IComparable<Mobile>, ISpawnable, IObjectPro
 
     public virtual bool CanBeDamaged() => !m_Blessed;
 
+    public void Damage(int amount, Mobile from, DamageType damageType)
+    {
+        var previousDamageType = _damageType;
+        _damageType = damageType;
+
+        try
+        {
+            Damage(amount, from);
+        }
+        finally
+        {
+            _damageType = previousDamageType;
+        }
+    }
+
     public virtual void Damage(int amount, Mobile from = null, bool informMount = true, bool ignoreEvilOmen = false)
     {
         if (amount <= 0)
@@ -5939,7 +5965,7 @@ public partial class Mobile : IHued, IComparable<Mobile>, ISpawnable, IObjectPro
         var oldHits = Hits;
         var newHits = oldHits - amount;
 
-        m_Spell?.OnCasterHurt();
+        m_Spell?.OnCasterHurt(_damageType);
 
         // if (m_Spell != null && m_Spell.State == SpellState.Casting)
         // m_Spell.Disturb( DisturbType.Hurt, false, true );
diff --git a/Projects/UOContent.Tests/Tests/Items/Weapons/ResonancePropertyTests.cs b/Projects/UOContent.Tests/Tests/Items/Weapons/ResonancePropertyTests.cs
new file mode 100644
index 000000000..7c6eeaf4c
--- /dev/null
+++ b/Projects/UOContent.Tests/Tests/Items/Weapons/ResonancePropertyTests.cs
@@ -0,0 +1,559 @@
+using System;
+using System.Collections.Generic;
+using System.Reflection;
+using Server;
+using Server.Items;
+using Server.Mobiles;
+using Server.Spells;
+using Server.Spells.Second;
+using Server.Tests;
+using Server.Text;
+using Xunit;
+
+namespace UOContent.Tests;
+
+[Collection("Sequential UOContent Tests")]
+public class ResonancePropertyTests
+{
+    private const int FireResonanceCliloc = 1154655;
+    private const int ColdResonanceCliloc = 1154656;
+    private const int PoisonResonanceCliloc = 1154657;
+    private const int EnergyResonanceCliloc = 1154658;
+    private const int KineticResonanceCliloc = 1154659;
+
+    [Fact]
+    public void AbsorptionAttributes_StoresDupesAndSerializesResonanceOnValidHostsOnly()
+    {
+        var shield = new BronzeShield { Layer = Layer.TwoHanded };
+        var shieldDupe = new BronzeShield { Layer = Layer.TwoHanded };
+        var shieldDeserialized = new BronzeShield { Layer = Layer.TwoHanded };
+        var weapon = new WarHammer();
+        var weaponDupe = new WarHammer();
+        var deserialized = new WarHammer();
+        var armor = new LeatherChest();
+        var oneHandedWeapon = new Katana();
+
+        try
+        {
+            SetAllResonance(shield.AbsorptionAttributes, 1);
+            SetAllResonance(weapon.AbsorptionAttributes, 6);
+            SetAllResonance(armor.AbsorptionAttributes, 11);
+            SetAllResonance(oneHandedWeapon.AbsorptionAttributes, 16);
+
+            shield.Dupe(shieldDupe);
+            weapon.Dupe(weaponDupe);
+
+            AssertResonance(shieldDupe.AbsorptionAttributes, 1);
+            AssertResonance(weaponDupe.AbsorptionAttributes, 6);
+            AssertResonance(armor.AbsorptionAttributes, 0);
+            AssertResonance(oneHandedWeapon.AbsorptionAttributes, 0);
+
+            var shieldWriter = new BufferWriter(true);
+            shield.Serialize(shieldWriter);
+            var shieldBuffer = new byte[shieldWriter.Position];
+            shieldWriter.Buffer.AsSpan(0, (int)shieldWriter.Position).CopyTo(shieldBuffer);
+
+            var shieldReader = new BufferReader(shieldBuffer);
+            shieldDeserialized.Deserialize(shieldReader);
+
+            Assert.Equal(shieldBuffer.Length, shieldReader.Position);
+            AssertResonance(shieldDeserialized.AbsorptionAttributes, 1);
+
+            var writer = new BufferWriter(true);
+            weapon.Serialize(writer);
+            var buffer = new byte[writer.Position];
+            writer.Buffer.AsSpan(0, (int)writer.Position).CopyTo(buffer);
+
+            var reader = new BufferReader(buffer);
+            deserialized.Deserialize(reader);
+
+            Assert.Equal(buffer.Length, reader.Position);
+            AssertResonance(deserialized.AbsorptionAttributes, 6);
+        }
+        finally
+        {
+            shield.Delete();
+            shieldDupe.Delete();
+            shieldDeserialized.Delete();
+            weapon.Delete();
+            weaponDupe.Delete();
+            deserialized.Delete();
+            armor.Delete();
+            oneHandedWeapon.Delete();
+        }
+    }
+
+    [Fact]
+    public void AbsorptionAttributes_ResonancePropertiesAreStaffEditable()
+    {
+        var weaponContainer = typeof(BaseWeapon).GetProperty(nameof(BaseWeapon.AbsorptionAttributes));
+        Assert.NotNull(weaponContainer);
+        Assert.True(weaponContainer.GetCustomAttribute<CommandPropertyAttribute>().CanModify);
+
+        var properties = new[]
+        {
+            nameof(AbsorptionAttributes.FireResonance),
+            nameof(AbsorptionAttributes.ColdResonance),
+            nameof(AbsorptionAttributes.PoisonResonance),
+            nameof(AbsorptionAttributes.EnergyResonance),
+            nameof(AbsorptionAttributes.KineticResonance)
+        };
+
+        foreach (var name in properties)
+        {
+            var property = typeof(AbsorptionAttributes).GetProperty(name);
+            Assert.NotNull(property);
+
+            var attribute = property.GetCustomAttribute<CommandPropertyAttribute>();
+            Assert.NotNull(attribute);
+            Assert.Equal(AccessLevel.GameMaster, attribute.ReadLevel);
+            Assert.Equal(AccessLevel.GameMaster, attribute.WriteLevel);
+        }
+    }
+
+    [Fact]
+    public void ResonanceTooltips_AreVisibleOnlyAtStygianAbyssOnShieldsAndTwoHandedWeapons()
+    {
+        var previousExpansion = Core.Expansion;
+        var shield = new BronzeShield { Layer = Layer.TwoHanded };
+        var weapon = new WarHammer();
+        var armor = new LeatherChest();
+
+        try
+        {
+            SetAllResonance(shield.AbsorptionAttributes, 1);
+            SetAllResonance(weapon.AbsorptionAttributes, 6);
+            SetAllResonance(armor.AbsorptionAttributes, 11);
+
+            Core.Expansion = Expansion.ML;
+            AssertNoResonanceTooltips(shield);
+            AssertNoResonanceTooltips(weapon);
+
+            Core.Expansion = Expansion.SA;
+            AssertResonanceTooltips(shield, 1);
+            AssertResonanceTooltips(weapon, 6);
+            AssertNoResonanceTooltips(armor);
+        }
+        finally
+        {
+            Core.Expansion = previousExpansion;
+            shield.Delete();
+            weapon.Delete();
+            armor.Delete();
+        }
+    }
+
+    [Fact]
+    public void ResonanceAggregation_UsesOnlyMatchingEligibleEquipmentAndCapsAtFortyPercent()
+    {
+        var previousExpansion = Core.Expansion;
+        var mobile = CreateMobile(player: true);
+        var shield = new BronzeShield { Layer = Layer.TwoHanded };
+        var weapon = new WarHammer();
+        var oneHandedWeapon = new Katana();
+
+        try
+        {
+            shield.AbsorptionAttributes.FireResonance = 25;
+            shield.AbsorptionAttributes.ColdResonance = 16;
+            weapon.AbsorptionAttributes.FireResonance = 25;
+            weapon.AbsorptionAttributes.PoisonResonance = 19;
+            oneHandedWeapon.AbsorptionAttributes.FireResonance = 99;
+
+            mobile.AddItem(shield);
+            mobile.AddItem(weapon);
+            mobile.AddItem(oneHandedWeapon);
+
+            Assert.Contains(shield, mobile.Items);
+            Assert.Contains(weapon, mobile.Items);
+            Assert.Contains(oneHandedWeapon, mobile.Items);
+            Assert.Equal(Layer.TwoHanded, shield.Layer);
+            Assert.Equal(Layer.TwoHanded, weapon.Layer);
+
+            Core.Expansion = Expansion.ML;
+            Assert.Equal(0, AbsorptionAttributes.GetResonanceValue(mobile, DamageType.Fire));
+
+            Core.Expansion = Expansion.SA;
+            Assert.Equal(AOS.ResonanceChanceCap, AbsorptionAttributes.GetResonanceValue(mobile, DamageType.Fire));
+            Assert.Equal(16, AbsorptionAttributes.GetResonanceValue(mobile, DamageType.Cold));
+            Assert.Equal(19, AbsorptionAttributes.GetResonanceValue(mobile, DamageType.Poison));
+            Assert.Equal(0, AbsorptionAttributes.GetResonanceValue(mobile, DamageType.Energy));
+            Assert.Equal(0, oneHandedWeapon.AbsorptionAttributes.FireResonance);
+        }
+        finally
+        {
+            Core.Expansion = previousExpansion;
+            shield.Delete();
+            weapon.Delete();
+            oneHandedWeapon.Delete();
+            mobile.Delete();
+        }
+    }
+
+    [Theory]
+    [InlineData(DamageType.Physical)]
+    [InlineData(DamageType.Fire)]
+    [InlineData(DamageType.Cold)]
+    [InlineData(DamageType.Poison)]
+    [InlineData(DamageType.Energy)]
+    public void TypedDamage_MatchingResonancePreservesCastWithoutChangingDamage(DamageType damageType)
+    {
+        var previousExpansion = Core.Expansion;
+        using var random = new PredictableRandom(0);
+        var caster = CreateMobile(player: true);
+        var source = CreateMobile(player: true);
+        var weapon = new WarHammer();
+
+        try
+        {
+            Core.Expansion = Expansion.SA;
+            SetResonance(weapon.AbsorptionAttributes, damageType, 1);
+            caster.AddItem(weapon);
+            var spell = SetCastingSpell(caster);
+            var hits = caster.Hits;
+
+            ApplyTypedDamage(caster, source, damageType);
+
+            Assert.Equal(hits - 10, caster.Hits);
+            Assert.Equal(SpellState.Casting, spell.State);
+            Assert.Same(spell, caster.Spell);
+            Assert.Equal(0, spell.DisturbCount);
+        }
+        finally
+        {
+            Core.Expansion = previousExpansion;
+            weapon.Delete();
+            caster.Delete();
+            source.Delete();
+        }
+    }
+
+    [Fact]
+    public void NonMatchingAndUntypedDamage_DisturbsNormallyAndTypedContextDoesNotLeak()
+    {
+        var previousExpansion = Core.Expansion;
+        using var random = new PredictableRandom(0);
+        var caster = CreateMobile(player: true);
+        var source = CreateMobile(player: true);
+        var weapon = new WarHammer();
+
+        try
+        {
+            Core.Expansion = Expansion.SA;
+            weapon.AbsorptionAttributes.FireResonance = 1;
+            caster.AddItem(weapon);
+
+            AssertDisturbsAfter(() => ApplyDamage(caster, source, physical: 50, fire: 50));
+            AssertDisturbsAfter(() => ApplyDamage(caster, source, fire: 100, chaos: 1));
+            AssertDisturbsAfter(() => ApplyDamage(caster, source, fire: 100, direct: 1));
+            AssertDisturbsAfter(() => caster.Damage(10));
+
+            var preservedSpell = SetCastingSpell(caster);
+            ApplyDamage(caster, source, fire: 100);
+            Assert.Equal(SpellState.Casting, preservedSpell.State);
+
+            AssertDisturbsAfter(() => caster.Damage(10));
+        }
+        finally
+        {
+            Core.Expansion = previousExpansion;
+            weapon.Delete();
+            caster.Delete();
+            source.Delete();
+        }
+
+        void AssertDisturbsAfter(Action action)
+        {
+            var spell = SetCastingSpell(caster);
+            action();
+            Assert.Equal(SpellState.None, spell.State);
+            Assert.Null(caster.Spell);
+            Assert.Equal(1, spell.DisturbCount);
+            Assert.Equal(DisturbType.Hurt, spell.LastDisturbType);
+        }
+    }
+
+    [Fact]
+    public void HurtPreservation_OrderIsProtectionThenCastingFocusThenResonance()
+    {
+        var previousExpansion = Core.Expansion;
+        var caster = CreateMobile(player: true);
+        var source = CreateMobile(player: true);
+        var weapon = new WarHammer();
+        var armor = new LeatherChest();
+
+        try
+        {
+            Core.Expansion = Expansion.SA;
+            weapon.AbsorptionAttributes.FireResonance = 1;
+            caster.AddItem(weapon);
+            caster.AddItem(armor);
+
+            using (new PredictableRandom(0))
+            {
+                ProtectionSpell.Registry[caster] = 1000;
+                var protectionSpell = SetCastingSpell(caster);
+                ApplyDamage(caster, source, fire: 100);
+                Assert.Equal(SpellState.Casting, protectionSpell.State);
+                Assert.Equal(0, protectionSpell.DisturbCount);
+            }
+
+            ProtectionSpell.Registry[caster] = -1;
+            armor.AbsorptionAttributes.CastingFocus = 1;
+            using (new PredictableRandom(0))
+            {
+                var focusSpell = SetCastingSpell(caster);
+                ApplyDamage(caster, source, fire: 100);
+                Assert.Equal(SpellState.Casting, focusSpell.State);
+                Assert.Equal(0, focusSpell.DisturbCount);
+            }
+
+            armor.AbsorptionAttributes.CastingFocus = 0;
+            using (new PredictableRandom(0))
+            {
+                var resonanceSpell = SetCastingSpell(caster);
+                ApplyDamage(caster, source, fire: 100);
+                Assert.Equal(SpellState.Casting, resonanceSpell.State);
+                Assert.Equal(0, resonanceSpell.DisturbCount);
+            }
+
+            ProtectionSpell.Registry.Remove(caster);
+            using (new PredictableRandom(99))
+            {
+                var failedSpell = SetCastingSpell(caster);
+                ApplyDamage(caster, source, fire: 100);
+                Assert.Equal(SpellState.None, failedSpell.State);
+                Assert.Equal(1, failedSpell.DisturbCount);
+            }
+        }
+        finally
+        {
+            ProtectionSpell.Registry.Remove(caster);
+            Core.Expansion = previousExpansion;
+            weapon.Delete();
+            armor.Delete();
+            caster.Delete();
+            source.Delete();
+        }
+    }
+
+    [Fact]
+    public void Resonance_DoesNotChangeNonPlayerOrNonHurtDisturbanceBehavior()
+    {
+        var previousExpansion = Core.Expansion;
+        using var random = new PredictableRandom(0);
+        var creature = CreateMobile(player: false);
+        var weapon = new WarHammer();
+
+        try
+        {
+            Core.Expansion = Expansion.SA;
+            weapon.AbsorptionAttributes.FireResonance = 40;
+            creature.AddItem(weapon);
+            var spell = SetCastingSpell(creature);
+
+            ApplyDamage(creature, null, fire: 100);
+            Assert.Equal(SpellState.Casting, spell.State);
+            Assert.Equal(0, spell.DisturbCount);
+
+            creature.Player = true;
+            spell.Disturb(DisturbType.EquipRequest, false, true);
+            Assert.Equal(SpellState.None, spell.State);
+            Assert.Equal(1, spell.DisturbCount);
+            Assert.Equal(DisturbType.EquipRequest, spell.LastDisturbType);
+        }
+        finally
+        {
+            Core.Expansion = previousExpansion;
+            weapon.Delete();
+            creature.Delete();
+        }
+    }
+
+    private static void SetAllResonance(AbsorptionAttributes attributes, int value)
+    {
+        attributes.FireResonance = value;
+        attributes.ColdResonance = value + 1;
+        attributes.PoisonResonance = value + 2;
+        attributes.EnergyResonance = value + 3;
+        attributes.KineticResonance = value + 4;
+    }
+
+    private static void AssertResonance(AbsorptionAttributes attributes, int value)
+    {
+        Assert.Equal(value, attributes.FireResonance);
+        Assert.Equal(value + (value == 0 ? 0 : 1), attributes.ColdResonance);
+        Assert.Equal(value + (value == 0 ? 0 : 2), attributes.PoisonResonance);
+        Assert.Equal(value + (value == 0 ? 0 : 3), attributes.EnergyResonance);
+        Assert.Equal(value + (value == 0 ? 0 : 4), attributes.KineticResonance);
+    }
+
+    private static void SetResonance(AbsorptionAttributes attributes, DamageType damageType, int value)
+    {
+        switch (damageType)
+        {
+            case DamageType.Physical:
+                attributes.KineticResonance = value;
+                break;
+            case DamageType.Fire:
+                attributes.FireResonance = value;
+                break;
+            case DamageType.Cold:
+                attributes.ColdResonance = value;
+                break;
+            case DamageType.Poison:
+                attributes.PoisonResonance = value;
+                break;
+            case DamageType.Energy:
+                attributes.EnergyResonance = value;
+                break;
+            default:
+                throw new ArgumentOutOfRangeException(nameof(damageType));
+        }
+    }
+
+    private static void AssertNoResonanceTooltips(Item item)
+    {
+        var list = new RecordingPropertyList();
+        item.GetProperties(list);
+        Assert.DoesNotContain(list.Entries, entry => IsResonanceCliloc(entry.Number));
+    }
+
+    private static void AssertResonanceTooltips(Item item, int firstValue)
+    {
+        var list = new RecordingPropertyList();
+        item.GetProperties(list);
+        Assert.Contains(list.Entries, entry => entry.Number == FireResonanceCliloc && entry.Argument == firstValue.ToString());
+        Assert.Contains(list.Entries, entry => entry.Number == ColdResonanceCliloc && entry.Argument == (firstValue + 1).ToString());
+        Assert.Contains(list.Entries, entry => entry.Number == PoisonResonanceCliloc && entry.Argument == (firstValue + 2).ToString());
+        Assert.Contains(list.Entries, entry => entry.Number == EnergyResonanceCliloc && entry.Argument == (firstValue + 3).ToString());
+        Assert.Contains(list.Entries, entry => entry.Number == KineticResonanceCliloc && entry.Argument == (firstValue + 4).ToString());
+    }
+
+    private static bool IsResonanceCliloc(int number) => number is FireResonanceCliloc or ColdResonanceCliloc or PoisonResonanceCliloc or EnergyResonanceCliloc or KineticResonanceCliloc;
+
+    private static void ApplyTypedDamage(Mobile defender, Mobile source, DamageType type)
+    {
+        switch (type)
+        {
+            case DamageType.Physical:
+                ApplyDamage(defender, source, physical: 100);
+                break;
+            case DamageType.Fire:
+                ApplyDamage(defender, source, fire: 100);
+                break;
+            case DamageType.Cold:
+                ApplyDamage(defender, source, cold: 100);
+                break;
+            case DamageType.Poison:
+                ApplyDamage(defender, source, poison: 100);
+                break;
+            case DamageType.Energy:
+                ApplyDamage(defender, source, energy: 100);
+                break;
+            default:
+                throw new ArgumentOutOfRangeException(nameof(type));
+        }
+    }
+
+    private static void ApplyDamage(
+        Mobile defender,
+        Mobile source,
+        int physical = 0,
+        int fire = 0,
+        int cold = 0,
+        int poison = 0,
+        int energy = 0,
+        int chaos = 0,
+        int direct = 0
+    ) => AOS.Damage(defender, source, 10, true, physical, fire, cold, poison, energy, chaos, direct);
+
+    private static Mobile CreateMobile(bool player)
+    {
+        var mobile = new Mobile(World.NewMobile);
+        mobile.DefaultMobileInit();
+        mobile.Player = player;
+        mobile.RawStr = 100;
+        mobile.Hits = mobile.HitsMax;
+        mobile.MoveToWorld(new Point3D(6200, 500, 0), Map.Felucca);
+        return mobile;
+    }
+
+    private static TestSpell SetCastingSpell(Mobile caster)
+    {
+        var spell = new TestSpell(caster)
+        {
+            State = SpellState.Casting
+        };
+
+        caster.Spell = spell;
+        return spell;
+    }
+
+    private sealed class TestSpell : Spell
+    {
+        private static readonly SpellInfo TestInfo = new("Test Spell", "test");
+
+        public TestSpell(Mobile caster) : base(caster, null, TestInfo)
+        {
+        }
+
+        public int DisturbCount { get; private set; }
+        public DisturbType LastDisturbType { get; private set; }
+        public override TimeSpan CastDelayBase => TimeSpan.Zero;
+        public override void OnCast()
+        {
+        }
+
+        public override int GetMana() => 0;
+
+        public override void OnDisturb(DisturbType type, bool message)
+        {
+            DisturbCount++;
+            LastDisturbType = type;
+        }
+    }
+
+    private sealed record PropertyEntry(int Number, string Argument);
+
+    private sealed class RecordingPropertyList : IPropertyList
+    {
+        private string _interpolated = string.Empty;
+
+        public List<PropertyEntry> Entries { get; } = [];
+
+        public void Reset()
+        {
+        }
+
+        public void Terminate()
+        {
+        }
+
+        public void Add(int number) => Entries.Add(new PropertyEntry(number, string.Empty));
+        public void Add(int number, string argument) => Entries.Add(new PropertyEntry(number, argument));
+        public void Add(ReadOnlySpan<char> argument) => Entries.Add(new PropertyEntry(0, argument.ToString()));
+        public void Add(int number, ReadOnlySpan<char> argument) => Entries.Add(new PropertyEntry(number, argument.ToString()));
+        public void AddChunked(ReadOnlySpan<char> text) => Entries.Add(new PropertyEntry(0, text.ToString()));
+        public OplTextBlock TextBlock() => new(this);
+        public void Add(int number, int value) => Entries.Add(new PropertyEntry(number, value.ToString()));
+        public void AddLocalized(int value) => Entries.Add(new PropertyEntry(0, value.ToString()));
+        public void AddLocalized(int number, int value) => Entries.Add(new PropertyEntry(number, value.ToString()));
+        public void Add(ref IPropertyList.InterpolatedStringHandler handler) => Entries.Add(new PropertyEntry(0, _interpolated));
+        public void Add(int number, ref IPropertyList.InterpolatedStringHandler handler) => Entries.Add(new PropertyEntry(number, _interpolated));
+        public void InitializeInterpolation(int literalLength, int formattedCount) => _interpolated = string.Empty;
+        public void AppendLiteral(string value) => _interpolated += value;
+        public void AppendFormatted<T>(T value) => _interpolated += value;
+        public void AppendFormatted<T>(T value, string format) =>
+            _interpolated += value is IFormattable formattable ? formattable.ToString(format, null) : value;
+        public void AppendFormatted<T>(T value, int alignment) => _interpolated += value;
+        public void AppendFormatted<T>(T value, int alignment, string format) =>
+            _interpolated += value is IFormattable formattable ? formattable.ToString(format, null) : value;
+        public void AppendFormatted(ReadOnlySpan<char> value) => _interpolated += value.ToString();
+        public void AppendFormatted(ReadOnlySpan<char> value, int alignment, string format = null) =>
+            _interpolated += value.ToString();
+        public void AppendFormatted(object value, int alignment = 0, string format = null) => _interpolated += value;
+        public void AppendFormatted(string value) => _interpolated += value;
+        public void AppendFormatted(string value, int alignment, string format = null) => _interpolated += value;
+    }
+}
diff --git a/Projects/UOContent/Items/Weapons/BaseWeapon.Migrations.cs b/Projects/UOContent/Items/Weapons/BaseWeapon.Migrations.cs
index 019a79aa2..750f4cd49 100644
--- a/Projects/UOContent/Items/Weapons/BaseWeapon.Migrations.cs
+++ b/Projects/UOContent/Items/Weapons/BaseWeapon.Migrations.cs
@@ -113,4 +113,43 @@ public abstract partial class BaseWeapon
         _negativeAttributes = content.NegativeAttributes ?? NegativeAttributesDefaultValue();
         _unwieldyOriginalWeight = -1;
     }
+
+    private void MigrateFrom(V13Content content)
+    {
+        _damageLevel = content.DamageLevel ?? WeaponDamageLevel.Regular;
+        _accuracyLevel = content.AccuracyLevel ?? WeaponAccuracyLevel.Regular;
+        _durabilityLevel = content.DurabilityLevel ?? WeaponDurabilityLevel.Regular;
+        _quality = content.Quality ?? WeaponQuality.Regular;
+        _hitPoints = content.HitPoints ?? 0;
+        _maxHitPoints = content.MaxHitPoints ?? 0;
+        _slayer = content.Slayer ?? SlayerName.None;
+        _poison = content.Poison;
+        _poisonCharges = content.PoisonCharges ?? 0;
+        _crafter = content.Crafter;
+        _identified = content.Identified;
+        _strRequirement = content.StrRequirement ?? -1;
+        _dexRequirement = content.DexRequirement ?? -1;
+        _intRequirement = content.IntRequirement ?? -1;
+        _minDamage = content.MinDamage ?? -1;
+        _maxDamage = content.MaxDamage ?? -1;
+        _hitSound = content.HitSound ?? -1;
+        _missSound = content.MissSound ?? -1;
+        _speed = content.Speed ?? -1;
+        _maxRange = content.MaxRange ?? -1;
+        _skill = content.Skill ?? (SkillName)(-1);
+        _type = content.Type ?? (WeaponType)(-1);
+        _animation = content.Animation ?? (WeaponAnimation)(-1);
+        _resource = content.Resource ?? CraftResource.Iron;
+        _attributes = content.Attributes ?? AttributesDefaultValue();
+        _weaponAttributes = content.WeaponAttributes ?? WeaponAttributesDefaultValue();
+        _playerConstructed = content.PlayerConstructed;
+        _skillBonuses = content.SkillBonuses ?? SkillBonusesDefaultValue();
+        _slayer2 = content.Slayer2 ?? SlayerName.None;
+        _aosElementDamages = content.AosElementDamages ?? AosElementAttributesDefaultValue();
+        _engravedText = content.EngravedText;
+        _extendedWeaponAttributes = content.ExtendedWeaponAttributes ?? ExtendedWeaponAttributesDefaultValue();
+        _negativeAttributes = content.NegativeAttributes ?? NegativeAttributesDefaultValue();
+        _unwieldyOriginalWeight = content.UnwieldyOriginalWeight ?? -1;
+        _absorptionAttributes = AbsorptionAttributesDefaultValue();
+    }
 }
diff --git a/Projects/UOContent/Items/Weapons/BaseWeapon.cs b/Projects/UOContent/Items/Weapons/BaseWeapon.cs
index 946a579ce..ec85a241e 100644
--- a/Projects/UOContent/Items/Weapons/BaseWeapon.cs
+++ b/Projects/UOContent/Items/Weapons/BaseWeapon.cs
@@ -28,7 +28,7 @@ public interface ISlayer
     SlayerName Slayer2 { get; set; }
 }
 
-[SerializationGenerator(13, false)]
+[SerializationGenerator(14, false)]
 public abstract partial class BaseWeapon
     : Item, IWeapon, IFactionItem, ICraftable, ISlayer, IDurability, IAosItem, IIdentifiable
 {
@@ -214,6 +214,15 @@ public abstract partial class BaseWeapon
     [SerializableField(33)]
     private double _unwieldyOriginalWeight = -1;
 
+    // Field 34 intentionally has no save flag; BaseWeapon's legacy save-flag mask is already at the high bit.
+    [SerializedIgnoreDupe]
+    [SerializableField(34, setter: "private")]
+    [SerializedCommandProperty(AccessLevel.GameMaster, canModify: true)]
+    private AbsorptionAttributes _absorptionAttributes;
+
+    [SerializableFieldDefault(34)]
+    private AbsorptionAttributes AbsorptionAttributesDefaultValue() => new(this);
+
     private FactionItem m_FactionState;
     private SkillMod m_SkillMod, m_MageMod;
     private int _lastParryChance;
@@ -244,6 +253,7 @@ public abstract partial class BaseWeapon
         WeaponAttributes = new AosWeaponAttributes(this);
         ExtendedWeaponAttributes = new ExtendedWeaponAttributes(this);
         NegativeAttributes = new NegativeAttributes(this);
+        AbsorptionAttributes = new AbsorptionAttributes(this);
         SkillBonuses = new AosSkillBonuses(this);
         AosElementDamages = new AosElementAttributes(this);
     }
@@ -987,6 +997,7 @@ public abstract partial class BaseWeapon
         weap.AosElementDamages = new AosElementAttributes(newItem, AosElementDamages);
         weap.ExtendedWeaponAttributes = new ExtendedWeaponAttributes(newItem, ExtendedWeaponAttributes);
         weap.NegativeAttributes = new NegativeAttributes(newItem, NegativeAttributes);
+        weap.AbsorptionAttributes = new AbsorptionAttributes(newItem, AbsorptionAttributes);
         weap.SkillBonuses = new AosSkillBonuses(newItem, SkillBonuses);
         weap.WeaponAttributes = new AosWeaponAttributes(newItem, WeaponAttributes);
         weap._unwieldyOriginalWeight = _unwieldyOriginalWeight;
@@ -3986,6 +3997,7 @@ public abstract partial class BaseWeapon
     {
         _extendedWeaponAttributes ??= ExtendedWeaponAttributesDefaultValue();
         _negativeAttributes ??= NegativeAttributesDefaultValue();
+        _absorptionAttributes ??= AbsorptionAttributesDefaultValue();
         ReconcileUnwieldyWeight();
 
         var parentMobile = Parent as Mobile;
diff --git a/Projects/UOContent/Misc/AOS.cs b/Projects/UOContent/Misc/AOS.cs
index 1ee77ee4e..173397f08 100644
--- a/Projects/UOContent/Misc/AOS.cs
+++ b/Projects/UOContent/Misc/AOS.cs
@@ -15,6 +15,7 @@ namespace Server
     public static class AOS
     {
         public const int CastingFocusChanceCap = 12;
+        public const int ResonanceChanceCap = 40;
         public const int MassiveStrengthRequirement = 125;
 
         public static void DisableStatInfluences()
@@ -78,6 +79,8 @@ namespace Server
             Fix(ref chaos);
             Fix(ref direct);
 
+            var damageType = GetDamageType(phys, fire, cold, pois, nrgy, chaos, direct);
+
             var physicalPostResistDamage = 0;
             var firePostResistDamage = 0;
             var coldPostResistDamage = 0;
@@ -267,7 +270,7 @@ namespace Server
             }
 
             var oldHits = m.Hits;
-            m.Damage(totalDamage, from);
+            m.Damage(totalDamage, from, damageType);
             var appliedDamage = Math.Max(0, oldHits - m.Hits);
 
             PurgeMagicSpell.OnMobileDamaged(from, m, appliedDamage);
@@ -301,6 +304,24 @@ namespace Server
             }
         }
 
+        private static DamageType GetDamageType(int phys, int fire, int cold, int pois, int nrgy, int chaos, int direct)
+        {
+            if (chaos != 0 || direct != 0)
+            {
+                return DamageType.None;
+            }
+
+            return (phys, fire, cold, pois, nrgy) switch
+            {
+                (100, 0, 0, 0, 0) => DamageType.Physical,
+                (0, 100, 0, 0, 0) => DamageType.Fire,
+                (0, 0, 100, 0, 0) => DamageType.Cold,
+                (0, 0, 0, 100, 0) => DamageType.Poison,
+                (0, 0, 0, 0, 100) => DamageType.Energy,
+                _                  => DamageType.None
+            };
+        }
+
         public static int Scale(int input, int percent) => input * percent / 100;
 
         public static int GetStatus(Mobile from, int index)
@@ -1374,7 +1395,12 @@ namespace Server
         FireEater = 0x00000008,
         ColdEater = 0x00000010,
         PoisonEater = 0x00000020,
-        EnergyEater = 0x00000040
+        EnergyEater = 0x00000040,
+        FireResonance = 0x00000080,
+        ColdResonance = 0x00000100,
+        PoisonResonance = 0x00000200,
+        EnergyResonance = 0x00000400,
+        KineticResonance = 0x00000800
     }
 
     public sealed class AbsorptionAttributes : BaseAttributes
@@ -1442,6 +1468,41 @@ namespace Server
             set => SetEaterValue(AbsorptionAttribute.EnergyEater, value);
         }
 
+        [CommandProperty(AccessLevel.GameMaster)]
+        public int FireResonance
+        {
+            get => CanHaveResonance ? this[AbsorptionAttribute.FireResonance] : 0;
+            set => SetResonanceValue(AbsorptionAttribute.FireResonance, value);
+        }
+
+        [CommandProperty(AccessLevel.GameMaster)]
+        public int ColdResonance
+        {
+            get => CanHaveResonance ? this[AbsorptionAttribute.ColdResonance] : 0;
+            set => SetResonanceValue(AbsorptionAttribute.ColdResonance, value);
+        }
+
+        [CommandProperty(AccessLevel.GameMaster)]
+        public int PoisonResonance
+        {
+            get => CanHaveResonance ? this[AbsorptionAttribute.PoisonResonance] : 0;
+            set => SetResonanceValue(AbsorptionAttribute.PoisonResonance, value);
+        }
+
+        [CommandProperty(AccessLevel.GameMaster)]
+        public int EnergyResonance
+        {
+            get => CanHaveResonance ? this[AbsorptionAttribute.EnergyResonance] : 0;
+            set => SetResonanceValue(AbsorptionAttribute.EnergyResonance, value);
+        }
+
+        [CommandProperty(AccessLevel.GameMaster)]
+        public int KineticResonance
+        {
+            get => CanHaveResonance ? this[AbsorptionAttribute.KineticResonance] : 0;
+            set => SetResonanceValue(AbsorptionAttribute.KineticResonance, value);
+        }
+
         internal bool HasDamageEater =>
             DamageEater != 0 || KineticEater != 0 || FireEater != 0 || ColdEater != 0 || PoisonEater != 0 || EnergyEater != 0;
 
@@ -1455,6 +1516,11 @@ namespace Server
             }
         }
 
+        private bool CanHaveResonance => Owner is BaseShield or BaseWeapon { Layer: Layer.TwoHanded };
+
+        private void SetResonanceValue(AbsorptionAttribute attribute, int value) =>
+            this[attribute] = CanHaveResonance ? value : 0;
+
         public static int GetValue(Mobile m, AbsorptionAttribute attribute)
         {
             if (!Core.SA || m == null)
@@ -1473,6 +1539,15 @@ namespace Server
                 {
                     var attrs = armor.AbsorptionAttributes;
 
+                    if (attrs != null)
+                    {
+                        value += attrs[attribute];
+                    }
+                }
+                else if (IsResonance(attribute) && obj is BaseWeapon weapon)
+                {
+                    var attrs = weapon.AbsorptionAttributes;
+
                     if (attrs != null)
                     {
                         value += attrs[attribute];
@@ -1483,6 +1558,26 @@ namespace Server
             return value;
         }
 
+        internal static int GetResonanceValue(Mobile m, DamageType damageType)
+        {
+            AbsorptionAttribute attribute = damageType switch
+            {
+                DamageType.Physical => AbsorptionAttribute.KineticResonance,
+                DamageType.Fire     => AbsorptionAttribute.FireResonance,
+                DamageType.Cold     => AbsorptionAttribute.ColdResonance,
+                DamageType.Poison   => AbsorptionAttribute.PoisonResonance,
+                DamageType.Energy   => AbsorptionAttribute.EnergyResonance,
+                _                   => (AbsorptionAttribute)0
+            };
+
+            return attribute == 0 ? 0 : Math.Min(AOS.ResonanceChanceCap, Math.Max(0, GetValue(m, attribute)));
+        }
+
+        private static bool IsResonance(AbsorptionAttribute attribute) => attribute is
+            AbsorptionAttribute.FireResonance or AbsorptionAttribute.ColdResonance or
+            AbsorptionAttribute.PoisonResonance or AbsorptionAttribute.EnergyResonance or
+            AbsorptionAttribute.KineticResonance;
+
         internal static bool HasDamageEaterOn(Mobile m)
         {
             if (!Core.SA || m == null)
@@ -1551,6 +1646,31 @@ namespace Server
                 {
                     list.Add(1113596, EnergyEater); // Energy Eater ~1_val~%
                 }
+
+                if (FireResonance != 0)
+                {
+                    list.Add(1154655, FireResonance); // Fire Resonance ~1_val~%
+                }
+
+                if (ColdResonance != 0)
+                {
+                    list.Add(1154656, ColdResonance); // Cold Resonance ~1_val~%
+                }
+
+                if (PoisonResonance != 0)
+                {
+                    list.Add(1154657, PoisonResonance); // Poison Resonance ~1_val~%
+                }
+
+                if (EnergyResonance != 0)
+                {
+                    list.Add(1154658, EnergyResonance); // Energy Resonance ~1_val~%
+                }
+
+                if (KineticResonance != 0)
+                {
+                    list.Add(1154659, KineticResonance); // Kinetic Resonance ~1_val~%
+                }
             }
         }
 
diff --git a/Projects/UOContent/Skills/SpiritSpeak.cs b/Projects/UOContent/Skills/SpiritSpeak.cs
index 53590c0df..755d53c14 100644
--- a/Projects/UOContent/Skills/SpiritSpeak.cs
+++ b/Projects/UOContent/Skills/SpiritSpeak.cs
@@ -93,7 +93,7 @@ namespace Server.SkillHandlers
 
             public override int GetMana() => 0;
 
-            public override void OnCasterHurt()
+            public override void OnCasterHurt(DamageType damageType)
             {
                 if (IsCasting)
                 {
diff --git a/Projects/UOContent/Spells/Base/Spell.cs b/Projects/UOContent/Spells/Base/Spell.cs
index 2c96d932c..86ac47058 100644
--- a/Projects/UOContent/Spells/Base/Spell.cs
+++ b/Projects/UOContent/Spells/Base/Spell.cs
@@ -84,7 +84,7 @@ namespace Server.Spells
 
         public virtual bool IsCasting => State == SpellState.Casting;
 
-        public virtual void OnCasterHurt()
+        public virtual void OnCasterHurt(DamageType damageType = DamageType.None)
         {
             // Confirm: Monsters and pets cannot be disturbed.
             if (Caster.Player && IsCasting)
@@ -106,6 +106,12 @@ namespace Server.Spells
                     return;
                 }
 
+                var resonance = AbsorptionAttributes.GetResonanceValue(Caster, damageType);
+                if (resonance > 0 && resonance > Utility.Random(100))
+                {
+                    return;
+                }
+
                 Disturb(DisturbType.Hurt, false, true);
             }
         }