diff --git a/ProjectObsidian/ProtoFlux/Math/Factorial.cs b/ProjectObsidian/ProtoFlux/Math/Factorial.cs
new file mode 100644
index 0000000..158cc8d
--- /dev/null
+++ b/ProjectObsidian/ProtoFlux/Math/Factorial.cs
@@ -0,0 +1,24 @@
+using System;
+using Elements.Core;
+using ProtoFlux.Core;
+using ProtoFlux.Runtimes.Execution;
+using FrooxEngine.ProtoFlux;
+
+namespace ProtoFlux.Runtimes.Execution.Nodes.Obsidian.Math
+{
+    [NodeCategory("Obsidian/Math")]
+    [NodeName("Factorial")]
+    public class FactorialNode : ValueFunctionNode<FrooxEngineContext, int>
+    {
+        public ValueInput<int> Input;
+
+        protected override int Compute(FrooxEngineContext context)
+        {
+            var input = Input.Evaluate(context);
+            var fact = 1;
+            var loop = MathX.Clamp(input, 0, 16);
+            for (var i = 1; i <= loop; i++) fact *= i;
+            return fact;
+        }
+    }
+}