As an additional cost to cast Altar's Reap, sacrifice a creature.Draw two cards.
Regler omkring kortet.120 Drawing a Card120.1 A player draws a card by putting the top card of his or her library into his or her hand. This is done as a turn-based action during each player’s draw step. It may also be done as part of a cost or effect of a spell or ability.120.2 Cards may only be drawn one at a time. If a player is instructed to draw multiple cards, that player performs that many individual card draws.120.2a If an effect instructs more than one player to draw cards, the active player performs all of his or her draws first, then each other player in turn order does the same.120.2b If an effect instructs more than one player to draw cards in a game that’s using the shared team turns option (such as a Two-Headed Giant game), first each player on the active team, in whatever order that team likes, performs his or her draws, then each player on each nonactive team in turn order does the same.120.3 If there are no cards in a player’s library and an effect offers that player the choice to draw a card, that player can choose to do so. However, if an effect says that a player can’t draw cards and another effect offers that player the choice to draw a card, that player can’t choose to do so.120.3a The same principles apply if the player who’s making the choice is not the player who would draw the card. If the latter player has no cards in his or her library, the choice can be taken. If an effect says that the latter player can’t draw a card, the choice can’t be taken.120.4 A player who attempts to draw a card from a library with no cards in it loses the game the next time a player would receive priority. (This is a state-based action. See rule 704.)120.5 If an effect moves cards from a player’s library to that player’s hand without using the word “draw,” the player has not drawn those cards. This makes a difference for abilities that trigger on drawing cards and effects that replace card draws, as well as if the player’s library is empty.120.6 Some effects replace card draws.120.6a An effect that replaces a card draw is applied even if no cards could be drawn because there are no cards in the affected player’s library.120.6b If an effect replaces a draw within a sequence of card draws, the replacement effect is completed before resuming the sequence.120.6c Some effects perform additional actions on a card after it’s drawn. If the draw is replaced, the additional action is not performed on any cards that are drawn as a result of that replacement effect or any subsequent replacement effects.120.7 Some replacement effects and prevention effects result in one or more card draws. In such a case, if there are any parts of the original event that haven’t been replaced, those parts occur first, then the card draws happen one at a time.