You can't have more than 1 Silver in your deck.

If you have 6 remaining Prize cards, or fewer Prize cards left than your opponent, you can't play this card. Take the top card from your deck (without looking at it), and show it to your opponent. Add that card to your remaining Prize cards. Then, search your deck for a Trainer card, a Basic Energy card and a Basic Pokémon card. Show them to your opponent, and put them into your hand. Shuffle your deck afterward.