Historical Rules · 28 April 2017
Rule 100.4
Official source text from the 28 April 2017 Rules release
Each player may also have a sideboard, which is a group of additional cards the player may use to modify his or her deck between games of a match.
Historical Rules · 28 April 2017
Official source text from the 28 April 2017 Rules release
Each player may also have a sideboard, which is a group of additional cards the player may use to modify his or her deck between games of a match.