diff --git a/GamecraftModdingAPI/Commands/CommandBuilder.cs b/GamecraftModdingAPI/Commands/CommandBuilder.cs
index f0f9258..d5f1b51 100644
--- a/GamecraftModdingAPI/Commands/CommandBuilder.cs
+++ b/GamecraftModdingAPI/Commands/CommandBuilder.cs
@@ -19,6 +19,8 @@ namespace GamecraftModdingAPI.Commands
 
 		private ICustomCommandEngine commandEngine;
 
+		private bool fromExisting = false;
+
 		/// <summary>
         /// Create a new command builder.
         /// </summary>
@@ -138,6 +140,96 @@ namespace GamecraftModdingAPI.Commands
             return this;
         }
 
+        /// <summary>
+        /// Build the command from an existing command.
+        /// </summary>
+        /// <returns>The command. Use Invoke() to execute it.</returns>
+		public SimpleCustomCommandEngine FromExisting()
+		{
+			if (string.IsNullOrWhiteSpace(name))
+            {
+                throw new InvalidOperationException("Command name must be defined before FromExisting() is called");
+            }
+			if (!ExistingCommands.Exists(name))
+			{
+				throw new InvalidOperationException("Command cannot be built from existing because it does not exist.");
+			}
+			fromExisting = true;
+			return new SimpleCustomCommandEngine(
+				() => { ExistingCommands.Call(name); },
+				name,
+				description);
+		}
+
+		/// <summary>
+        /// Build the command from an existing command.
+        /// </summary>
+        /// <returns>The command. Use Invoke() to execute it.</returns>
+        /// <typeparam name="A">The 1st parameter's type.</typeparam>
+		public SimpleCustomCommandEngine<A> FromExisting<A>()
+        {
+            if (string.IsNullOrWhiteSpace(name))
+            {
+                throw new InvalidOperationException("Command name must be defined before FromExisting() is called");
+            }
+			if (!ExistingCommands.Exists(name))
+            {
+                throw new InvalidOperationException("Command cannot be built from existing because it does not exist.");
+            }
+			fromExisting = true;
+            return new SimpleCustomCommandEngine<A>(
+                (A a) => { ExistingCommands.Call<A>(name, a); },
+                name,
+                description);
+        }
+
+		/// <summary>
+        /// Build the command from an existing command.
+        /// </summary>
+        /// <returns>The command. Use Invoke() to execute it.</returns>
+        /// <typeparam name="A">The 1st parameter's type.</typeparam>
+        /// <typeparam name="B">The 2nd parameter's type.</typeparam>
+		public SimpleCustomCommandEngine<A,B> FromExisting<A,B>()
+        {
+            if (string.IsNullOrWhiteSpace(name))
+            {
+                throw new InvalidOperationException("Command name must be defined before FromExisting() is called");
+            }
+			if (!ExistingCommands.Exists(name))
+            {
+                throw new InvalidOperationException("Command cannot be built from existing because it does not exist.");
+            }
+			fromExisting = true;
+            return new SimpleCustomCommandEngine<A,B>(
+                (A a, B b) => { ExistingCommands.Call<A,B>(name, a, b); },
+                name,
+                description);
+        }
+
+		/// <summary>
+        /// Build the command from an existing command.
+        /// </summary>
+        /// <returns>The command. Use Invoke() to execute it.</returns>
+        /// <typeparam name="A">The 1st parameter's type.</typeparam>
+		/// <typeparam name="B">The 2nd parameter's type.</typeparam>
+		/// <typeparam name="C">The 3rd parameter's type.</typeparam>
+		public SimpleCustomCommandEngine<A,B,C> FromExisting<A,B,C>()
+        {
+            if (string.IsNullOrWhiteSpace(name))
+            {
+                throw new InvalidOperationException("Command name must be defined before FromExisting() is called");
+            }
+			if (!ExistingCommands.Exists(name))
+            {
+                throw new InvalidOperationException("Command cannot be built from existing because it does not exist.");
+            }
+			fromExisting = true;
+            return new SimpleCustomCommandEngine<A,B,C>(
+                (A a, B b, C c) => { ExistingCommands.Call<A,B,C>(name, a, b, c); },
+                name,
+                description);
+        }
+
         /// <summary>
         /// Build the command.
         /// </summary>
@@ -149,6 +241,10 @@ namespace GamecraftModdingAPI.Commands
 			{
 				throw new InvalidOperationException("Command name must be defined before Build() is called");
 			}
+			if (fromExisting)
+			{
+				throw new InvalidOperationException("Command was already built by FromExisting()");
+			}
 			if (commandEngine == null)
 			{
 				throw new InvalidOperationException("Command action must be defined before Build() is called");
diff --git a/GamecraftModdingAPI/Commands/SimpleCustomCommandEngine.cs b/GamecraftModdingAPI/Commands/SimpleCustomCommandEngine.cs
index d99edce..ebf0758 100644
--- a/GamecraftModdingAPI/Commands/SimpleCustomCommandEngine.cs
+++ b/GamecraftModdingAPI/Commands/SimpleCustomCommandEngine.cs
@@ -57,5 +57,10 @@ namespace GamecraftModdingAPI.Commands
             this.Name = name;
             this.Description = description;
         }
+
+        public void Invoke()
+		{
+			runCommand();
+		}
     }
 }
diff --git a/GamecraftModdingAPI/Commands/SimpleCustomCommandEngine1.cs b/GamecraftModdingAPI/Commands/SimpleCustomCommandEngine1.cs
index 307cac6..a8dd96b 100644
--- a/GamecraftModdingAPI/Commands/SimpleCustomCommandEngine1.cs
+++ b/GamecraftModdingAPI/Commands/SimpleCustomCommandEngine1.cs
@@ -47,6 +47,11 @@ namespace GamecraftModdingAPI.Commands
             this.runCommand = command;
             this.Name = name;
             this.Description = description;
+        }
+
+		public void Invoke(A a)
+        {
+            runCommand(a);
         }
     }
 }
diff --git a/GamecraftModdingAPI/Commands/SimpleCustomCommandEngine2.cs b/GamecraftModdingAPI/Commands/SimpleCustomCommandEngine2.cs
index 2e162aa..8333cd2 100644
--- a/GamecraftModdingAPI/Commands/SimpleCustomCommandEngine2.cs
+++ b/GamecraftModdingAPI/Commands/SimpleCustomCommandEngine2.cs
@@ -47,6 +47,11 @@ namespace GamecraftModdingAPI.Commands
             this.runCommand = command;
             this.Name = name;
             this.Description = description;
+        }
+
+		public void Invoke(A a, B b)
+        {
+            runCommand(a, b);
         }
     }
 }
diff --git a/GamecraftModdingAPI/Commands/SimpleCustomCommandEngine3.cs b/GamecraftModdingAPI/Commands/SimpleCustomCommandEngine3.cs
index e88b153..e5570c3 100644
--- a/GamecraftModdingAPI/Commands/SimpleCustomCommandEngine3.cs
+++ b/GamecraftModdingAPI/Commands/SimpleCustomCommandEngine3.cs
@@ -47,6 +47,11 @@ namespace GamecraftModdingAPI.Commands
             this.runCommand = command;
             this.Name = name;
             this.Description = description;
+        }
+
+		public void Invoke(A a, B b, C c)
+        {
+            runCommand(a, b, c);
         }
     }
 }