So you are asking yourself what the heck does NPN mean?? Basically “no purchase necessary” It is a way card companies get away with offering cards at an extreme ratio. So say autographs are listed 1 out of every 3400 pack of cards.  That is a form of lottery and and they must follow the “lottery law” They must offer a way where no purchase is necessary so they usually give you an address to mail and you fill out a 3×5 index card (along with a stamp of course)  with your address for a chance at a card at no charge outside of postage.   Also due to Canadian laws residents of Canada are also required to answer a math question also included.  ( unsure if you really have to get the math question right just a way to make it legal)

One thing though Upper Deck has gone one step ahead and listed their NPN’s online so you don’t have to mail in.  You still have debate how many times you can enter either one a day or one period.  I have heard people entered once a day and still got something one thing is for sure I would make sure not to enter more than once in the same day just to make sure that doesn’t automatically disqualify yourself.