1. Go to Marketing > Affiliates > Affiliate Rules and click Add Rule (/admin/affiliate/rules/0).
2. Leave Is Active on, enter a Rule Name (e.g. "Standard 10% Commission") and optionally a Contract Ending date/time ("Optional — leave blank for no end date"; the × clears it).
3. Under Commission Steps click Add Step. Each row has an Expires After number with Days/Months/Years, and a Commission value with Percent/Flat. The first row is labelled On First, later rows Then After; use the trash icon to remove a step.
4. Click Save Rule.

"Invalid Name!" appears if the name is empty. The rules list has Active and Inactive tabs showing ID and Name, and a How to Create video button.