If an effect instructs a player to choose a subtype, that player must choose one, and only one, existing subtype, and the subtype must be for the appropriate card type. For example, the player can’t choose a land type if an instruction requires choosing a creature type.
January 25, 2019 · Ravnica Allegiance
If an effect instructs a player to choose a subtype, that player must choose one, and only one, existing subtype, and the subtype must be for the appropriate card type. For example, the player can't choose a land type if an instruction requires choosing a creature type.
April 27, 2018 · Dominaria
If an effect instructs a player to choose a subtype, that player must choose one, and only one, existing subtype, and the subtype must be for the appropriate card type. For example, the player can’t choose a land type if an instruction requires choosing a creature type.
February 1, 2014 · Born of the Gods
If an effect instructs a player to choose a subtype, that player must choose one, and only one, existing subtype, and the subtype he or she chooses must be for the appropriate card type. For example, the player can’t choose a land type if an instruction requires choosing a creature type.
September 30, 2011 · Innistrad
If an effect instructs a player to choose a subtype, that player must choose one, and only one, existing subtype, and the subtype he or she chooses must be for the appropriate card type. For example, the player can't choose a land type if an instruction requires choosing a creature type.