---
title: "Creating a Tree Rule"
slug: "tree-rule"
description: "This document shows how to create a Tree Rule in Decisions. Tree Rules possess one axis to establish two parameters, where Matrix Rules have two. A Tree Rule can be created by making a Default Matrix Rule, and then setting Rule Type to Tree [One Axis], under the Settings. "
updated: 2025-06-17T20:35:23Z
published: 2025-06-17T20:35:23Z
---

> ## Documentation Index
> Fetch the complete documentation index at: https://documentation.decisions.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Creating a Tree Rule

## Overview

A **Tree Rule**is a subtype of a [Matrix Rule](/v9/docs/about-matrix-rules), with values evaluated on one axis instead of two. When compared to Matrix Rules or [Truth Tables](/v9/docs/creating-a-truth-table), Tree Rules are mainly used when conditions contain branching paths that lead to a single result.

A Tree Rule can only add new Rule evaluations as nested columns, and results are displayed in the rightmost column. Below is an example of a Tree Rule.

![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/image-1656354638089.png)

---

## Example

1. In a Designer Project, [Create a Matrix Rule](/v9/docs/about-matrix-rules).
2. On the Properties panel under the SETTINGS category, click the drop-down list under **Rule Type** and select **Tree [One Axis].**  
**![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/2025-06-17_16h28_20.png) ******
3. Click SETUP INPUT DATA.
4. Click DEFINE. Enter "EmployeeTeam" in the **Name**field. Click **Save**and close the **Input Data** window.  
![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/2025-06-17_16h29_19.png)
5. Hover over **Add Rule** and click the plus sign.
6. Navigate to **All Rules > Data > Text** and select **Is Empty** Rule. Click ADD.![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/2025-06-17_16h30_10.png)
7. On the **Edit Rule** window, select **Unknown** next to the **Value** field and select **Flow Data****.** Select **EmployeeTeam** and click DONE. Click CLOSE to close the Edit Rule window.  
![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/2025-06-17_16h31_46.png)
8. Click the check box on the **False**row to change the value to False.
9. Hover over the False cell under the Is Empty column. and click the plus sign**.**
10. Navigate to **All Rules > Data > Text** and select the **String is in List** Rule. Click ADD.
11. Under the INPUTS category, select Unknown next to the **Case Insensitive** field and select **Constant**. Click on the check box that appears. Make the **List**field a Constant and enter “Accounting", "Marketing" and "IT.” Click Unknown next to the **Value**field and select **Flow Data**. Select EmployeeTeam and click DONE.  
![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/2025-06-17_16h34_16.png)

---

## Debug

1. On the top action bar, click **Debug**. Enter "IT" for the Employee Team field and click START DEBUGGING. The outcome path and result will be highlighted within the debugger.

![](https://cdn.document360.io/6ef8bcc1-6489-4486-9ad1-83acff7e5df0/Images/Documentation/2025-06-17_16h35_08.png)

---

For further information on Rules, visit the [Decisions Forum](https://community.decisions.com/categories/Rules).