Sealed Format is a Deck format used at Sneak Peek events. In this format, players are given unopened packs and make Decks with a minimum of 20 cards, using only cards they get in these packs. The usual Deck-build rules don't apply here. A player can have as many copies of a card as he/she likes in their Main Deck, Side Deck or Extra Deck if they get more than 3 copies. Also, all cards that you don't use in your Deck are used as your Side Deck.