Each state has a different set of rules and guidelines as to when and for which part of a sale is to be charged sales tax. Petersen Games strives to collect and remit sales tax per the end user's state and local guidelines. Please see your state's Department of Revenue website for more information related specifically to your state.
We must pay sales tax to each state (which has sales tax) as well as each city and/or county which also charges sales tax. It is impractical to have each city/county in our system for purposes of sales taxes, even though we must pay it to them. So, we use what is called the "combined" rate, which is the sum of the state sales tax and the average of that state's local taxes.