4/27/2018 If the mana cost of a card in your graveyard includes , X is considered to be 0.

4/27/2018 A card, spell, or permanent is historic if it has the legendary supertype, the artifact card type, or the Saga subtype. Having two of those qualities doesn¡¯t make an object more historic than another or provide an additional bonus¡ªan object either is historic or it isn¡¯t.

4/27/2018 Some abilities trigger ¡°whenever you cast a historic spell.¡± Such an ability resolves before the spell that caused it to trigger. It resolves even if that spell is countered.

4/27/2018 An ability that triggers ¡°whenever you cast a historic spell¡± doesn¡¯t trigger if a historic card is put onto the battlefield without being cast.

4/27/2018 Lands are never cast, so abilities that trigger ¡°whenever you cast a historic spell¡± won¡¯t trigger if you play a legendary land. They also won¡¯t trigger if a card on the battlefield transforms into a legendary land, as the Ixalan and Rivals of Ixalan double-faced cards do.