Signed Hero Cards

I wonder how booster packs works, I mean, when you get a Hero in a booster pack it comes with its 3 signed card copies? If not, I supposed to get the other 2 copies to be able to play the hero in a constructed deck? I believe that is compulsory to play the 3 copies of the signed card. I´m wrong?
Thank you in advance.
When you open a pack, you are guaranteed a Hero card. Hero cards will come with 3 copies of their signature card, automatically.
Whenever you put a Hero into a deck, you are forced to run 3 copies of their signature card.
Here is a pack simulator :
You have 12 cards (+3 signed cards). Among these cards you will have at least 1 rare and 3 uncommon cards. You have a low chance for your normal/uncommon cards to be rare cards instead.
List of cards : 1 Hero - 9 Minions/Spells/Improvements - 2 Items