At the beginning of your upkeep, each player reveals the top card of their library, loses life equal to that card's converted mana cost, then puts it into their hand.
1/24/2013 The loss of life is simultaneous. If this causes both players to end up at 0 or less life, the game will be a draw. In a multiplayer game, players with 0 or less life will lose the game.
1/24/2013 The cards put into hands this way are not “drawn.” For example, you couldn’t reveal a card with miracle put into your hand this way (but it also won’t count as the first card you’ve drawn this turn either).