Index -> Interface -> Tournaments Lobby -> Sealed Tournaments
Sealed tournaments require you to bring either Event Passes and/or an unopened starter deck and unopened booster packs. Decks and packs are opened at the start of the tournament, then each player is given some time to use the Limited Deck Builder and construct a deck from that limited card pool. Players cannot access any other cards in their collections for this kind of tournament.
In most Sealed Tournaments, you will have 15 minutes to build your deck (in Release Events, you will have more time to browse the new cards). Decks in a Sealed Tournament must conform to the deck requirements of a Constructed tournament. Use the Deck Validator to make sure your deck is legal in the format you are playing.
Be sure to click Save once you have completed your deck. If you do not save a valid deck within the time limit, you will play the first round with the basic starter deck.
You may modify your deck between rounds in a Sealed Tournament. You can do this by clicking on the Deck Builder navigation button (either from the Main Lobby or from the Tournament Lobby). Please note that you cannot return to the normal Deck Builder until the tournament has concluded or you have dropped from the tournament.