What occurs if a player cannot draw a card from a library with no cards in it?

When a player attempts to draw a card from an empty library, the rules of Magic: The Gathering dictate that the player loses the game. This outcome is established in the Comprehensive Rules, specifically in Rule 104.3, which states that if a player is instructed to draw a card and there are no cards in their library, that player loses the game. This rule ensures that players must carefully manage their libraries and provides a clear consequence for running out of cards.

Other outcomes, such as the game continuing without consequences or the player skipping their next turn, do not align with the established rules. Additionally, reshuffling the graveyard is not allowed as part of standard gameplay and does not apply in this situation. The rules aim to create a consistent and fair game environment, and the loss condition for empty libraries is a key feature of that balance.