SOLVED! Thank you very much.
First time I ever created a cart rule. I followed your instructions and added / updated a bit, as I was creating the rule to buy two and get the 3rd free, as follows:
Solution for the cart rule: Buy 3 Pay 2:
Open admin. Go to Price Rules > Cart Rules
Add new Cart Rule (press the plus sign above this statement)
Create a name. Description is optional.
Information Partial Use YES Priority 1 Status YES
Conditions Valid optional, choose any date or leave blank. Required now. Total available Should be > 0, depends on the frequency of your shop Total available for each user Minimum 1
Restrictions: Compatibility with other cart rules Choose if necessary
Click on Product Selection Choose at least 1 of Products, Attributes, Categories, Manufacturers or Suppliers [or combine them by clicking Product selection once again.
I entered "3" for the "The cart must contain at least __ products matching the following rules.
I selected Add a rule concerning "Categories". Pressed "Add". Pressed "Choose". Chose two categories (dog dresses and dog shirts). Clicked to "add" them. Closed that dialog box.
Actions Apply a Discount Choose Percent Value 100 % (filled in 100). Apply A Discount to Cheapest Product
I attached the screenshots for each section and for the successful rule application in the cart.
I have a couple of questions:
1. I selected "Yes" for "highlight". Where is it highlighted?
2. Total available Should be > 0, depends on the frequency of your shop What do you mean "frequency of my shop", please? I put "1" but I want this to be an ongoing rule.
Note: I'm using Transformer theme 3 for PS 1.6 and TB 1.0.8.