

One of the most popular uses of dredge is to use it to quickly fill your graveyard.

702.52b A player with fewer cards in their library than the number required by a dredge ability can’t mill any of them this way.“Dredge N” means “As long as you have at least N cards in your library, if you would draw a card, you may instead mill N cards and return this card from your graveyard to your hand.” 702.52a Dredge is a static ability that functions only while the card with dredge is in a player’s graveyard.

From the Comprehensive Rules (June 16, 2023- The Lord of the Rings: Tales of Middle-earth)
