In this rule

Historical Rules · 29 April 2022

Rule 121.3a

Official source text from the 29 April 2022 Rules release

Permalink

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 their 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.

Find this number in the current Rules