diff --git a/L4/L4.sln b/L4/L4.sln
index 46eaa1a..4e27aad 100644
--- a/L4/L4.sln
+++ b/L4/L4.sln
@@ -5,6 +5,8 @@ VisualStudioVersion = 17.1.32328.378
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "LD_24", "LD_24\LD_24.csproj", "{4B4C2BFE-C41E-4EA1-BC86-979E2CA1D27B}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "LD_24Tests", "LD_24Tests\LD_24Tests.csproj", "{D1567F9E-F2A5-48D9-B581-1B76DEC9F21E}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -15,6 +17,10 @@ Global
 		{4B4C2BFE-C41E-4EA1-BC86-979E2CA1D27B}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{4B4C2BFE-C41E-4EA1-BC86-979E2CA1D27B}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{4B4C2BFE-C41E-4EA1-BC86-979E2CA1D27B}.Release|Any CPU.Build.0 = Release|Any CPU
+		{D1567F9E-F2A5-48D9-B581-1B76DEC9F21E}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{D1567F9E-F2A5-48D9-B581-1B76DEC9F21E}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{D1567F9E-F2A5-48D9-B581-1B76DEC9F21E}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{D1567F9E-F2A5-48D9-B581-1B76DEC9F21E}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
diff --git a/L4/LD_24Tests/LD_24Tests.csproj b/L4/LD_24Tests/LD_24Tests.csproj
new file mode 100644
index 0000000..40a7ddd
--- /dev/null
+++ b/L4/LD_24Tests/LD_24Tests.csproj
@@ -0,0 +1,27 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>netcoreapp3.1</TargetFramework>
+
+    <IsPackable>false</IsPackable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="FluentAssertions" Version="6.6.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.11.0" />
+    <PackageReference Include="xunit" Version="2.4.1" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+    <PackageReference Include="coverlet.collector" Version="3.1.0">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\LD_24\LD_24.csproj" />
+  </ItemGroup>
+
+</Project>
diff --git a/L4/LD_24Tests/TaskUtilsTests.cs b/L4/LD_24Tests/TaskUtilsTests.cs
new file mode 100644
index 0000000..25c7728
--- /dev/null
+++ b/L4/LD_24Tests/TaskUtilsTests.cs
@@ -0,0 +1,42 @@
+using System;
+using Xunit;
+using LD_24.Code;
+using System.Collections.Generic;
+using FluentAssertions;
+
+namespace LD_24Tests
+{
+    public class TaskUtilsTests
+    {
+        [Fact]
+        public void TestFindAllClasses()
+        {
+            List<Actor> actors = new List<Actor>();
+            actors.Add(new NPC("foo", "bar", "baz", "ClassAAA", 10, 10, 10, 10, "biz"));
+            actors.Add(new Hero("foo", "bar", "baz", "ClassBBB", 10, 10, 10, 10, 10, 10, 10, 10));
+            actors.Add(new NPC("foo", "bar", "baz", "ClassBBB", 10, 10, 10, 10, "baz"));
+            actors.Add(new Hero("foo", "bar", "baz", "ClassCCC", 10, 10, 10, 10, 10, 10, 10, 10));
+            List<string> classes = TaskUtils.FindAllClasses(actors);
+            classes.Should().BeEquivalentTo("ClassAAA", "ClassBBB", "ClassCCC");
+        }
+
+        [Fact]
+        public void TestFilterNPCsByAttack()
+        {
+            List<Actor> actors = new List<Actor>();
+            var actor1 = new NPC("foo", "bar", "baz", "ClassAAA", 10, 10, 9, 10, "biz");
+            var actor2 = new Hero("foo", "bar", "baz", "ClassBBB", 10, 10, 10, 10, 10, 10, 10, 10);
+            var actor3 = new NPC("foo", "bar", "baz", "ClassBBB", 10, 10, 10, 10, "baz");
+            var actor4 = new Hero("foo", "bar", "baz", "ClassCCC", 10, 10, 10, 10, 10, 10, 10, 10);
+            var actor5 = new NPC("foo", "bar", "baz", "ClassBBB", 10, 10, 5, 10, "baz");
+
+            actors.Add(actor1);
+            actors.Add(actor2);
+            actors.Add(actor3);
+            actors.Add(actor4);
+            actors.Add(actor5);
+            var NPCs = TaskUtils.FilterNPCsByAttack(actors, 10);
+            NPCs.Should().BeEquivalentTo(new List<NPC> { actor1, actor5 });
+        }
+    }
+}