You may reveal a sorcery card you own from outside the game and put it into your hand. Exile Burning Wish.
In a sanctioned event, a card that’s “outside the game” is one that’s in your sideboard. In an unsanctioned event, you may choose any card from your collection.
You can’t acquire exiled cards because those cards are still in one of the game’s zones.
Can’t acquire cards that are phased out.
Can’t acquire the Ante cards. They are considered still “in the game” as are cards in the library and the graveyard.