1. Log in to the [Cloudflare dashboard](https://dash.cloudflare.com), and select your account and domain.

2. Go to **Security** > **WAF** > **Custom rules**.

3. To create a new empty rule, select **Create rule**. To duplicate an existing rule, select the three dots next to it > **Duplicate**.

4. []()

   Enter a descriptive name for the rule in **Rule name**.

   ![Custom rule creation page in the Cloudflare dashboard](https://developers.cloudflare.com/_astro/firewall-custom-rule-create.DlnBR0Yl_Z1anVa8.webp)

5. Under **If incoming requests match**, use the **Field** drop-down list to choose an HTTP property. For each request, the value of the property you choose for **Field** is compared to the value you specify for **Value** using the operator selected in **Operator**.

6. Under **Then take action**, select the rule action in the **Choose action** dropdown. For example, selecting *Block* tells Cloudflare to refuse requests that match the conditions you specified.

7. (Optional) If you selected the *Block* action, you can [configure a custom response](#configure-a-custom-response-for-blocked-requests).

8. To save and deploy your rule, select **Deploy**. If you are not ready to deploy your rule, select **Save as Draft**.

## Configure a custom response for blocked requests

When you select the *Block* action in a rule you can optionally define a custom response.

The custom response has three settings:

* **With response type**: Choose a content type or the default WAF block response from the list. The available custom response types are the following:

  | Dashboard value | API value |
  | - | - |
  | Custom HTML | `"text/html"` |
  | Custom Text | `"text/plain"` |
  | Custom JSON | `"application/json"` |
  | Custom XML | `"text/xml"` |

* **With response code**: Choose an HTTP status code for the response, in the range 400-499. The default response code is 403.

* **Response body**: The body of the response. Configure a valid body according to the response type you selected. The maximum field size is 2 KB.
