When adding Play Steps, you can choose to update a Contact or Account Attribute as part of the Play. The option to update an Account or a Contact field corresponds with the play Target type that has been selected -- Account or Contact.
Note: Only fields that are editable on the Account/Contact profiles can be updated via a Play Step
Select which field(s) you would like to update, and what the new value should be when the Play Step occurs. Use the "Add Field" button if you would like to add more than one attribute.