MTG Keyword Rules — Comprehensive Rules Glossary

To shuffle a library or a face-down pile of cards, randomize the cards within it so that no player knows their order.

Some effects cause a player to search a library for a card or cards, shuffle that library, then put some or all of the found cards into a different zone or in a certain position in that library. In such cases, the found cards aren’t included in the shuffle, even though they remain in the library at that time. Rather, all the cards in that library except those are shuffled. Abilities that trigger when a library is shuffled will still trigger. See also rule 401, “Library.”

If an effect would cause a player to shuffle one or more specific objects into a library, that library is shuffled even if none of those objects are in the zone they’re expected to be in or an effect causes all of those objects to be moved to another zone or remain in their current zone. Example: Guile says, in part, “When Guile is put into a graveyard from anywhere, shuffle it into its owner’s library.” It’s put into a graveyard and its ability triggers, then a player exiles it from that graveyard in response. When the ability resolves, the library is shuffled. Example: Black Sun’s Zenith says, in part, “Shuffle Black Sun’s Zenith into its owner’s library.” Black Sun’s Zenith is in a graveyard, has gained flashback (due to Recoup, perhaps), and is cast from that graveyard. Black Sun’s Zenith will be exiled, and its owner’s library will be shuffled.

If an effect would cause a player to shuffle a set of objects into a library, that library is shuffled even if there are no objects in that set. Example: Loaming Shaman says “When this creature enters, target player shuffles any number of target cards from their graveyard into their library.” It enters the battlefield, its ability triggers, and no cards are targeted. When the ability resolves, the targeted player will still have to shuffle their library.

If an effect causes a player to shuffle a library containing zero or one cards, abilities that trigger when a library is shuffled will still trigger.

If two or more effects cause a library to be shuffled multiple times simultaneously, abilities that trigger when that library is shuffled will trigger that many times.

If an effect would cause a player to shuffle a library at the same time that an object would be put into a certain position in that library, the result is a shuffled library that’s randomized except that the object is in the specified position. Example: Darksteel Colossus and Gravebane Zombie are put into a player’s graveyard from the battlefield at the same time. Darksteel Colossus says in part “If Darksteel Colossus would be put into a graveyard from anywhere, reveal Darksteel Colossus and shuffle it into its owner’s library instead.” Gravebane Zombie says “If this creature would die, put it on top of its owner’s library instead.” The player shuffles Darksteel Colossus into their library and puts Gravebane Zombie on top of that library.