# How do I make a field change automatically?

Each automation is a rule on the field whose change starts it. When that field changes and the conditions hold, the rule sets or clears fields on the item or on its child items.

[Open in Teamhood](https://app.teamhood.com/go/settings/fields)

## Add an automation

1. In **Settings → General → Fields**, open the field, then choose **Automations**.
2. Choose **Add rule**.
3. Under **When**, choose **this item** or **a child item**.
4. Under **Condition**, choose **Add condition** once per condition. With no condition, the rule runs on every change.
5. Under **Actions**, choose **Add action**, then **Set** or **Clear**.
6. Choose which items it changes, then the field. With **a child item** under **When**, it can change **This item** only.
7. Choose **Save rule**.

## Choose what a condition tests

- In each condition, the first list picks which items it tests: **This item**, **All children**, **Any child** or **No child**. A condition on the item type has no such list.
- On the field that starts the rule, **Previous value** tests the field's value from before the change. It is offered only with **this item** under **When**.
- With two or more conditions, select **AND** to change it to **OR**. **AND** needs every condition to hold. **OR** needs only one.

## Choose the value an action sets

- **Value**: a value you pick.
- **Field**: the value of another field on the item.
- **Expression**: a calculation, on number, date and checkbox fields.
- **User who triggered**, **Today** or **Tomorrow**: on people and date fields.

A **Set** on **Child items** can add **Only children where** to limit which children change.

## Switch an automation off

Use the switch on the rule. A rule that is off keeps its settings and never runs.

You can also ask Chat to make, change or delete an automation. See [Ask in Chat](../../integrations/assistant/).

## Next

- [How automations work](../../how-it-works/automations/)
- [What is a field?](../what-is-a-field/)