Historical Rules · 18 June 2010
Rule 100.4b
Official source text from the 18 June 2010 Rules release
In limited play involving individual players, all cards a player opens but doesn't include in his or her deck are in that player's sideboard.
Historical Rules · 18 June 2010
Official source text from the 18 June 2010 Rules release
In limited play involving individual players, all cards a player opens but doesn't include in his or her deck are in that player's sideboard.