Conundrum Sphinx | Magic: The Gathering
Formats Conundrum Sphinx is Legal in
Official Oracle Text for Conundrum Sphinx
Whenever Conundrum Sphinx attacks, each player names a card. Then each player reveals the top card of his or her library. If the card a player revealed is the card he or she named, that player puts it into his or her hand. If it's not, that player puts it on the bottom of his or her library.
Official Rulings for Conundrum Sphinx
8/15/2010 : If a card a player reveals this way is the card that particular player named, he or she must put it into his or her hand. Otherwise, he or she must put it on the bottom of his or her library, even if it's the card a different player named. In no cases can a player leave the revealed card on top of his or her library.