If I play a spell that makes an opponent discard a card, but they have no cards in their hand, would they have to discard those cards from their library, or would nothing happen?
He is instructed to discard a card.
701.7a To discard a card, move it from its owner’s hand to that player’s graveyard.
It's impossible for him to discard a card, so he does as much as possible.
609.3. If an effect attempts to do something impossible, it does only as much as possible.
It does not affect him.
protected by doppelgreener Nov 26 '18 at 15:55
Thank you for your interest in this question.
Because it has attracted low-quality or spam answers that had to be removed, posting an answer now requires 10 reputation on this site (the association bonus does not count).
Would you like to answer one of these unanswered questions instead?