# Order amount promotion rules

Commerce Layer provides a promotional engine built on top of two main resources: [promotions](https://docs.commercelayer.io/core-api-reference/promotions) and [promotion rules](https://docs.commercelayer.io/core-api-reference/promotion_rules).

Order amount promotions rules are used to trigger the associated promotion only when the total amount of an order is over the specified one. Any other promotions already applied to the order (e.g. with higher [priority](https://docs.commercelayer.io/core-api-reference/promotions#priority-and-order-of-application)) are considered in the comparison and the specified amount is checked against the total discounted amount.

{% hint style="info" %}
Set the `use_subtotal` attribute to `true` (default is `false`) if you want to compare the specified amount that should trigger the promotion with the order's subtotal and exclude other discount calculations (if any).
{% endhint %}