Rule 708.6a

Anything that performs a positive comparison (such as asking if a card is red) or a relative comparison (such as asking if a card’s converted mana cost is 3 or less) involving one or more split cards in any zone other than the stack or involving one or more fused split spells gets only one answer. This answer is “yes” if either side of each split card in the comparison would return a “yes” answer if compared individually. Example: Void reads, “Choose a number. Destroy all artifacts and creatures with converted mana cost equal to that number. Then target player reveals his or her hand and discards all nonland cards with converted mana cost equal to the number.” If a player casts Void and chooses 1, his or her opponent would discard Assault/Battery because its converted mana costs are 1 and 4. The same is true if the player chooses 4. If the player chooses 5, however, Assault/Battery would be unaffected.

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