diff --git a/Content.IntegrationTests/Tests/PrototypeSaveTest.cs b/Content.IntegrationTests/Tests/PrototypeSaveTest.cs
index 9b354babb9..1213d652e0 100644
--- a/Content.IntegrationTests/Tests/PrototypeSaveTest.cs
+++ b/Content.IntegrationTests/Tests/PrototypeSaveTest.cs
@@ -40,7 +40,7 @@ public sealed class PrototypeSaveTest
     [Test]
     public async Task UninitializedSaveTest()
     {
-        // Apparently SpawnTest fails to clean  up properly. Due to the similarities, I'll assume this also fails.
+        // Apparently SpawnTest fails to clean up properly. Due to the similarities, I'll assume this also fails.
         await using var pairTracker = await PoolManager.GetServerClient();
         var server = pairTracker.Pair.Server;
 
@@ -190,14 +190,14 @@ public sealed class PrototypeSaveTest
         await pairTracker.CleanReturnAsync();
     }
 
-    private sealed class TestEntityUidContext : ISerializationContext,
+    public sealed class TestEntityUidContext : ISerializationContext,
         ITypeSerializer<EntityUid, ValueDataNode>
     {
         public SerializationManager.SerializerProvider SerializerProvider { get; }
         public bool WritingReadingPrototypes { get; set; }
 
         public string WritingComponent = string.Empty;
-        public EntityPrototype Prototype = default!;
+        public EntityPrototype? Prototype;
 
         public TestEntityUidContext()
         {
@@ -215,7 +215,7 @@ public sealed class PrototypeSaveTest
             IDependencyCollection dependencies, bool alwaysWrite = false,
             ISerializationContext? context = null)
         {
-            if (WritingComponent != "Transform" && !Prototype.NoSpawn)
+            if (WritingComponent != "Transform" && (Prototype?.NoSpawn == false))
             {
                 // Maybe this will be necessary in the future, but at the moment it just indicates that there is some
                 // issue, like a non-nullable entityUid data-field. If a component MUST have an entity uid to work with,
diff --git a/Content.IntegrationTests/Tests/PrototypeTests/PrototypeTests.cs b/Content.IntegrationTests/Tests/PrototypeTests/PrototypeTests.cs
new file mode 100644
index 0000000000..de1d9e1b90
--- /dev/null
+++ b/Content.IntegrationTests/Tests/PrototypeTests/PrototypeTests.cs
@@ -0,0 +1,52 @@
+using Robust.Shared.Prototypes;
+using Robust.UnitTesting;
+
+namespace Content.IntegrationTests.Tests.PrototypeTests;
+
+public sealed class PrototypeTests
+{
+    /// <summary>
+    /// This test writes all known prototypes as yaml files, then validates that the result is valid yaml.
+    /// Can help prevent instances where prototypes have bad C# default values.
+    /// </summary>
+    [Test]
+    public async Task TestAllPrototypesAreSerializable()
+    {
+        await using var pairTracker = await PoolManager.GetServerClient();
+        var context = new PrototypeSaveTest.TestEntityUidContext();
+        Assert.Multiple(() =>
+        {
+            Validate(pairTracker.Pair.Server, "server", context);
+
+            // TODO fix client serialization
+            //Validate(pairTracker.Pair.Client, "client", context);
+        });
+        await pairTracker.CleanReturnAsync();
+    }
+
+    public void Validate(RobustIntegrationTest.IntegrationInstance instance, string instanceId,
+        PrototypeSaveTest.TestEntityUidContext ctx)
+    {
+        var protoMan = instance.ResolveDependency<IPrototypeManager>();
+        var errors = protoMan.ValidateAllPrototypesSerializable(ctx);
+
+        if (errors.Count == 0)
+            return;
+
+        Assert.Multiple(() =>
+        {
+            foreach (var (kind, ids) in errors)
+            {
+                foreach (var (id, nodes) in ids)
+                {
+                    var msg = $"Error when validating {instanceId} prototype ({kind.Name}, {id}). Errors: \n";
+                    foreach (var errorNode in nodes)
+                    {
+                        msg += $" - {errorNode.ErrorReason}\n";
+                    }
+                    Assert.Fail(msg);
+                }
+            }
+        });
+    }
+}
diff --git a/Content.Server/Arcade/SpaceVillainGame/SpaceVillainArcadeComponent.cs b/Content.Server/Arcade/SpaceVillainGame/SpaceVillainArcadeComponent.cs
index 8c3979f287..db55284b1f 100644
--- a/Content.Server/Arcade/SpaceVillainGame/SpaceVillainArcadeComponent.cs
+++ b/Content.Server/Arcade/SpaceVillainGame/SpaceVillainArcadeComponent.cs
@@ -3,8 +3,6 @@ using Robust.Shared.Audio;
 using Robust.Shared.Prototypes;
 using Robust.Shared.Serialization.TypeSerializers.Implementations.Custom.Prototype.List;
 
-// TODO: ECS.
-
 namespace Content.Server.Arcade.SpaceVillain;
 
 [RegisterComponent]
@@ -93,16 +91,7 @@ public sealed class SpaceVillainArcadeComponent : SharedSpaceVillainArcadeCompon
     /// </summary>
     [ViewVariables(VVAccess.ReadWrite)]
     [DataField("possibleRewards", customTypeSerializer: typeof(PrototypeIdListSerializer<EntityPrototype>))]
-    public List<string> PossibleRewards = new()
-    {
-        "ToyMouse", "ToyAi", "ToyNuke", "ToyAssistant", "ToyGriffin", "ToyHonk", "ToyIan",
-        "ToyMarauder", "ToyMauler", "ToyGygax", "ToyOdysseus", "ToyOwlman", "ToyDeathRipley",
-        "ToyPhazon", "ToyFireRipley", "ToyReticence", "ToyRipley", "ToySeraph", "ToyDurand", "ToySkeleton",
-        "FoamCrossbow", "RevolverCapGun", "PlushieHampter", "PlushieLizard", "PlushieAtmosian", "PlushieSpaceLizard",
-        "PlushieNuke", "PlushieCarp", "PlushieRatvar", "PlushieNar", "PlushieSnake", "Basketball", "Football",
-        "PlushieRouny", "PlushieBee", "PlushieSlime", "BalloonCorgi", "ToySword", "CrayonBox", "BoxDonkSoftBox", "BoxCartridgeCap",
-        "HarmonicaInstrument", "OcarinaInstrument", "RecorderInstrument", "GunpetInstrument", "BirdToyInstrument", "PlushieXeno", "BeachBall"
-    };
+    public List<string> PossibleRewards = new();
 
     /// <summary>
     /// The minimum number of prizes the arcade machine can have.
diff --git a/Content.Server/Holiday/Celebrate/DefaultHolidayCelebrate.cs b/Content.Server/Holiday/Celebrate/DefaultHolidayCelebrate.cs
deleted file mode 100644
index 6c807e9544..0000000000
--- a/Content.Server/Holiday/Celebrate/DefaultHolidayCelebrate.cs
+++ /dev/null
@@ -1,12 +0,0 @@
-using Content.Server.Holiday.Interfaces;
-
-namespace Content.Server.Holiday.Celebrate
-{
-    public sealed class DefaultHolidayCelebrate : IHolidayCelebrate
-    {
-        public void Celebrate(HolidayPrototype holiday)
-        {
-            // Nada.
-        }
-    }
-}
diff --git a/Content.Server/Holiday/Greet/DefaultHolidayGreet.cs b/Content.Server/Holiday/Greet/DefaultHolidayGreet.cs
index fef7d462b8..f4bf2fbb20 100644
--- a/Content.Server/Holiday/Greet/DefaultHolidayGreet.cs
+++ b/Content.Server/Holiday/Greet/DefaultHolidayGreet.cs
@@ -2,6 +2,7 @@ using Content.Server.Holiday.Interfaces;
 
 namespace Content.Server.Holiday.Greet
 {
+    [DataDefinition]
     public sealed class DefaultHolidayGreet : IHolidayGreet
     {
         public string Greet(HolidayPrototype holiday)
diff --git a/Content.Server/Holiday/HolidayPrototype.cs b/Content.Server/Holiday/HolidayPrototype.cs
index 85640a80bc..6a3d9770c7 100644
--- a/Content.Server/Holiday/HolidayPrototype.cs
+++ b/Content.Server/Holiday/HolidayPrototype.cs
@@ -1,4 +1,3 @@
-using Content.Server.Holiday.Celebrate;
 using Content.Server.Holiday.Greet;
 using Content.Server.Holiday.Interfaces;
 using Content.Server.Holiday.ShouldCelebrate;
@@ -40,7 +39,7 @@ namespace Content.Server.Holiday
         private readonly IHolidayGreet _greet = new DefaultHolidayGreet();
 
         [DataField("celebrate")]
-        private readonly IHolidayCelebrate _celebrate = new DefaultHolidayCelebrate();
+        private readonly IHolidayCelebrate? _celebrate = null;
 
         public bool ShouldCelebrate(DateTime date)
         {
@@ -57,7 +56,7 @@ namespace Content.Server.Holiday
         /// </summary>
         public void Celebrate()
         {
-            _celebrate.Celebrate(this);
+            _celebrate?.Celebrate(this);
         }
     }
 }
diff --git a/Content.Server/Holiday/ShouldCelebrate/DefaultHolidayShouldCelebrate.cs b/Content.Server/Holiday/ShouldCelebrate/DefaultHolidayShouldCelebrate.cs
index ade68c5b20..342189df66 100644
--- a/Content.Server/Holiday/ShouldCelebrate/DefaultHolidayShouldCelebrate.cs
+++ b/Content.Server/Holiday/ShouldCelebrate/DefaultHolidayShouldCelebrate.cs
@@ -2,7 +2,7 @@ using Content.Server.Holiday.Interfaces;
 
 namespace Content.Server.Holiday.ShouldCelebrate
 {
-    [Virtual]
+    [Virtual, DataDefinition]
     public class DefaultHolidayShouldCelebrate : IHolidayShouldCelebrate
     {
         public virtual bool ShouldCelebrate(DateTime date, HolidayPrototype holiday)
diff --git a/Content.Server/Nutrition/EntitySystems/FlavorProfileSystem.cs b/Content.Server/Nutrition/EntitySystems/FlavorProfileSystem.cs
index c1e71c0f3e..9e20484c31 100644
--- a/Content.Server/Nutrition/EntitySystems/FlavorProfileSystem.cs
+++ b/Content.Server/Nutrition/EntitySystems/FlavorProfileSystem.cs
@@ -4,6 +4,7 @@ using Content.Server.Nutrition.Components;
 using Content.Shared.CCVar;
 using Content.Shared.Chemistry.Components;
 using Content.Shared.Chemistry.Reagent;
+using Content.Shared.Nutrition;
 using Microsoft.VisualBasic;
 using Robust.Shared.Configuration;
 using Robust.Shared.Prototypes;
@@ -102,9 +103,8 @@ public sealed class FlavorProfileSystem : EntitySystem
                 continue;
             }
 
-            var flavor = proto.Flavor;
-
-            flavors.Add(flavor);
+            if (proto.Flavor != null)
+                flavors.Add(proto.Flavor);
         }
 
         return flavors;
diff --git a/Content.Shared/Alert/AlertOrderPrototype.cs b/Content.Shared/Alert/AlertOrderPrototype.cs
index 27053c8c0d..5c75f1cb4c 100644
--- a/Content.Shared/Alert/AlertOrderPrototype.cs
+++ b/Content.Shared/Alert/AlertOrderPrototype.cs
@@ -1,4 +1,6 @@
-using Robust.Shared.Prototypes;
+using System.Linq;
+using Robust.Shared.Prototypes;
+using Robust.Shared.Utility;
 
 namespace Content.Shared.Alert
 {
@@ -14,22 +16,25 @@ namespace Content.Shared.Alert
         public string ID { get; } = default!;
 
         [DataField("order")]
-        private List<(string type, string alert)> Order
+        private (string type, string alert)[] Order
         {
+            // why would paul do this to me.
             get
             {
-                var res = new List<(string, string)>(_typeToIdx.Count + _categoryToIdx.Count);
+                var res = new (string, string)[_typeToIdx.Count + _categoryToIdx.Count];
 
                 foreach (var (type, id) in _typeToIdx)
                 {
-                    res.Insert(id, ("alertType", type.ToString()));
+                    res[id] = ("alertType", type.ToString());
                 }
 
                 foreach (var (category, id) in _categoryToIdx)
                 {
-                    res.Insert(id, ("category", category.ToString()));
+                    res[id] = ("category", category.ToString());
                 }
 
+                DebugTools.Assert(res.All(x => x != default));
+
                 return res;
             }
             set
diff --git a/Content.Shared/Body/Prototypes/BodyPrototypeSerializer.cs b/Content.Shared/Body/Prototypes/BodyPrototypeSerializer.cs
index 69503396ae..c149b84c63 100644
--- a/Content.Shared/Body/Prototypes/BodyPrototypeSerializer.cs
+++ b/Content.Shared/Body/Prototypes/BodyPrototypeSerializer.cs
@@ -19,6 +19,7 @@ public sealed class BodyPrototypeSerializer : ITypeReader<BodyPrototype, Mapping
     {
         var nodes = new List<ValidationNode>();
         var prototypes = dependencies.Resolve<IPrototypeManager>();
+        var factory = dependencies.Resolve<IComponentFactory>();
 
         var connections = new List<string>();
         if (slot.TryGet("connections", out SequenceDataNode? connectionsNode))
@@ -57,7 +58,7 @@ public sealed class BodyPrototypeSerializer : ITypeReader<BodyPrototype, Mapping
                     continue;
                 }
 
-                if (!organPrototype.HasComponent<OrganComponent>())
+                if (!organPrototype.HasComponent<OrganComponent>(factory))
                 {
                     nodes.Add(new ErrorNode(value, $"Organ {organ.Value} does not have a body component"));
                 }
diff --git a/Content.Shared/Chemistry/Reagent/ReagentPrototype.cs b/Content.Shared/Chemistry/Reagent/ReagentPrototype.cs
index 3c15174362..abf8fa8275 100644
--- a/Content.Shared/Chemistry/Reagent/ReagentPrototype.cs
+++ b/Content.Shared/Chemistry/Reagent/ReagentPrototype.cs
@@ -6,6 +6,7 @@ using Content.Shared.Chemistry.Components;
 using Content.Shared.Chemistry.Reaction;
 using Content.Shared.Database;
 using Content.Shared.FixedPoint;
+using Content.Shared.Nutrition;
 using Robust.Shared.Audio;
 using Robust.Shared.Map;
 using Robust.Shared.Prototypes;
@@ -60,8 +61,8 @@ namespace Content.Shared.Chemistry.Reagent
         [DataField("recognizable")]
         public bool Recognizable = false;
 
-        [DataField("flavor")]
-        public string Flavor { get; } = default!;
+        [DataField("flavor", customTypeSerializer:typeof(PrototypeIdSerializer<FlavorPrototype>))]
+        public string? Flavor;
 
         /// <summary>
         /// There must be at least this much quantity in a solution to be tasted.
diff --git a/Content.Server/Nutrition/Flavor.cs b/Content.Shared/Nutrition/Flavor.cs
similarity index 91%
rename from Content.Server/Nutrition/Flavor.cs
rename to Content.Shared/Nutrition/Flavor.cs
index 85dcdc2948..475b4e2e66 100644
--- a/Content.Server/Nutrition/Flavor.cs
+++ b/Content.Shared/Nutrition/Flavor.cs
@@ -1,6 +1,6 @@
 using Robust.Shared.Prototypes;
 
-namespace Content.Server.Nutrition;
+namespace Content.Shared.Nutrition;
 
 [Prototype("flavor")]
 public sealed class FlavorPrototype : IPrototype
diff --git a/Resources/Prototypes/Entities/Objects/Consumable/Food/Baked/pie.yml b/Resources/Prototypes/Entities/Objects/Consumable/Food/Baked/pie.yml
index b911c67a5b..681a84e2bf 100644
--- a/Resources/Prototypes/Entities/Objects/Consumable/Food/Baked/pie.yml
+++ b/Resources/Prototypes/Entities/Objects/Consumable/Food/Baked/pie.yml
@@ -261,7 +261,7 @@
   - type: FlavorProfile
     flavors:
       - meaty
-      - acidic
+      - acid
   - type: Sprite
     layers:
     - state: tin
@@ -277,7 +277,7 @@
   - type: FlavorProfile
     flavors:
       - meaty
-      - acidic
+      - acid
   - type: Sprite
     layers:
     - state: plate-small
diff --git a/Resources/Prototypes/Entities/Objects/Consumable/Food/burger.yml b/Resources/Prototypes/Entities/Objects/Consumable/Food/burger.yml
index c566df7a25..8b4ca3edc0 100644
--- a/Resources/Prototypes/Entities/Objects/Consumable/Food/burger.yml
+++ b/Resources/Prototypes/Entities/Objects/Consumable/Food/burger.yml
@@ -797,7 +797,7 @@
     flavors:
       - bun
       - meaty
-      - acidic
+      - acid
   - type: Sprite
     state: x
   - type: SolutionContainerManager
diff --git a/Resources/Prototypes/Entities/Objects/Consumable/Food/meat.yml b/Resources/Prototypes/Entities/Objects/Consumable/Food/meat.yml
index c56816dbdd..f66ed04207 100644
--- a/Resources/Prototypes/Entities/Objects/Consumable/Food/meat.yml
+++ b/Resources/Prototypes/Entities/Objects/Consumable/Food/meat.yml
@@ -489,7 +489,7 @@
   - type: FlavorProfile
     flavors:
       - meaty
-      - acidic
+      - acid
   - type: Tag
     tags:
     - Raw
@@ -1080,7 +1080,7 @@
   - type: FlavorProfile
     flavors:
       - meaty
-      - acidic
+      - acid
   - type: Tag
     tags:
     - Raw
diff --git a/Resources/Prototypes/Entities/Structures/Machines/Computers/arcades.yml b/Resources/Prototypes/Entities/Structures/Machines/Computers/arcades.yml
index 95ad1c02f9..e48268bdc5 100644
--- a/Resources/Prototypes/Entities/Structures/Machines/Computers/arcades.yml
+++ b/Resources/Prototypes/Entities/Structures/Machines/Computers/arcades.yml
@@ -35,6 +35,54 @@
   components:
   - type: SpaceVillainArcade
     rewardAmount: 0
+    possibleRewards:
+    - ToyMouse
+    - ToyAi
+    - ToyNuke
+    - ToyGriffin
+    - ToyHonk
+    - ToyIan
+    - ToyMarauder
+    - ToyMauler
+    - ToyGygax
+    - ToyOdysseus
+    - ToyOwlman
+    - ToyDeathRipley
+    - ToyPhazon
+    - ToyFireRipley
+    - ToyReticence
+    - ToyRipley
+    - ToySeraph
+    - ToyDurand
+    - ToySkeleton
+    - FoamCrossbow
+    - RevolverCapGun
+    - PlushieHampter
+    - PlushieLizard
+    - PlushieAtmosian
+    - PlushieSpaceLizard
+    - PlushieNuke
+    - PlushieCarp
+    - PlushieRatvar
+    - PlushieNar
+    - PlushieSnake
+    - Basketball
+    - Football
+    - PlushieRouny
+    - PlushieBee
+    - PlushieSlime
+    - BalloonCorgi
+    - ToySword
+    - CrayonBox
+    - BoxDonkSoftBox
+    - BoxCartridgeCap
+    - HarmonicaInstrument
+    - OcarinaInstrument
+    - RecorderInstrument
+    - GunpetInstrument
+    - BirdToyInstrument
+    - PlushieXeno
+    - BeachBall
   - type: WiresPanel
   - type: Wires
     LayoutId: Arcade
diff --git a/Resources/Prototypes/Reagents/Consumable/Food/condiments.yml b/Resources/Prototypes/Reagents/Consumable/Food/condiments.yml
index 3afa4c8b42..f5bde4ac21 100644
--- a/Resources/Prototypes/Reagents/Consumable/Food/condiments.yml
+++ b/Resources/Prototypes/Reagents/Consumable/Food/condiments.yml
@@ -73,7 +73,8 @@
   group: Foods
   desc: reagent-desc-ketchunaise
   physicalDesc: reagent-physical-desc-saucey
-  flavor: piquant
+  #I love it when people just make up fake prototypes.
+  #flavor: piquant
   color: "#fba399"
   recognizable: true
 
diff --git a/Resources/Prototypes/Reagents/toxins.yml b/Resources/Prototypes/Reagents/toxins.yml
index edaf29d6df..035be6e5d9 100644
--- a/Resources/Prototypes/Reagents/toxins.yml
+++ b/Resources/Prototypes/Reagents/toxins.yml
@@ -100,7 +100,7 @@
   group: Toxins
   desc: reagent-desc-polytrinic-acid
   physicalDesc: reagent-physical-desc-strong-smelling
-  flavor: acidic
+  flavor: acid
   color: "#a1000b"
   boilingPoint: 78.2 # This isn't a real chemical...
   meltingPoint: -19.4
@@ -143,7 +143,7 @@
   group: Toxins
   desc: reagent-desc-fluorosulfuric-acid
   physicalDesc: reagent-physical-desc-strong-smelling
-  flavor: acidic
+  flavor: acid
   color: "#5050ff"
   boilingPoint: 165
   meltingPoint: -87
@@ -179,7 +179,7 @@
   group: Toxins
   desc: reagent-desc-sulfuric-acid
   physicalDesc: reagent-physical-desc-oily
-  flavor: acidic
+  flavor: acid
   color: "#BF8C00"
   recognizable: true
   boilingPoint: 337.0