To keep track of how CPQ arrives at a final price for the customer (also known as Net Price), it uses a bunch of intermediary fields to represent specific adjustments. For example, Regular Price represents adjustments based on Discount Schedules, and is prorated if the quote line is a subscription. As a reminder, here are those fields -  CPQ price waterfall:

• Original Price
• List Price
• Special Price
• Regular Price
• Customer Price
• Partner Price
• Net Price

Use price rules that target List Price. It may surprise you to learn this, but we recommend that you target only one other price field: Special Price. You should leave Original Price alone so that it can act as a reference point, to compare against other prices to trigger approvals and validations, or to simply calculate margins correctly.

As for Regular Price, Customer Price, Partner Price, and Net Price, those are all prorated prices. Accounting for the prorate multiplier is problematic. The calculations quickly become complicated, and it’s very easy to introduce rounding errors. So, although it’s technically possible to target those fields, you really shouldn’t. Instead, stick to List Price and Special Price.