To shuffle a library or a face-down pile of cards, randomize the cards within it so that no player knows their order.
July 3, 2020 · Core Set 2021
A player may planeswalk only during a Planechase game. Only the planar controller may planeswalk. See rule 901, “Planechase.”
May 3, 2019 · War of the Spark
Only a scheme card may be set in motion, and only during an Archenemy game. Only the archenemy may set a scheme card in motion. See rule 312, “Schemes,” and rule 904, “Archenemy.”
January 25, 2019 · Ravnica Allegiance
Only a scheme card may be set in motion, and only during an Archenemy game. Only the archenemy may set a scheme card in motion. See rule 312, "Schemes," and rule 904, "Archenemy."
April 27, 2018 · Dominaria
Only a scheme card may be set in motion, and only during an Archenemy game. Only the archenemy may set a scheme card in motion. See rule 312, “Schemes,” and rule 904, “Archenemy.”
September 30, 2016 · Kaladesh
Only a face-up ongoing scheme card may be abandoned, and only during an Archenemy game. See rule 312, “Schemes,” and rule 904, “Archenemy.”
September 30, 2011 · Innistrad
To proliferate means to choose any number of permanents and/or players that have a counter, then give each exactly one additional counter of a kind that permanent or player already has.