708.1.
Split cards have two card faces on a single card. The back of a split card is the normal Magic
card back.
708.2.
In every zone except the stack, split cards have two sets of characteristics and two converted
mana costs. As long as a split card is a spell on the stack, only the characteristics of the half being
cast exist. The other half‘s characteristics are treated as though they didn‘t exist.
708.2a
If a player casts a split card, that player chooses which half of that split card he or she is
casting before putting it onto the stack. Only the half that is being cast is considered to be put
onto the stack.
708.3.
Each split card that consists of two halves with different colored mana symbols in their mana
costs is a multicolored card while it‘s not a spell on the stack. While it‘s a spell on the stack, it‘s
only the color or colors of the half being cast.
708.4.
Although split cards have two castable halves, each split card is only one card. For example, a
player who has drawn or discarded a split card has drawn or discarded one card, not two.
708.5.
An effect that asks for a particular characteristic of a split card while it‘s in a zone other than the
stack gets two answers (one for each of the split card‘s two halves).
Example: Infernal Genesis has an ability that reads, “At the beginning of each player?s
upkeep, that player puts the top card from his or her library into his or her graveyard. He or
she then puts X 1/1 black Minion creature tokens onto the battlefield, where X is that card?s
converted mana cost.” If the top card of your library is Assault/Battery when this ability
resolves, the game sees its converted mana cost as “1, and 4.” You get five creature tokens.
708.6.
Some effects perform comparisons involving characteristics of one or more split cards in a zone
other than the stack.
708.6a
An effect 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 less than 2) involving
characteristics of one or more split cards in any zone other than the stack 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.
708.6b
An effect that performs a negative comparison (such as asking if cards have different names)
involving characteristics of one or more split cards in any zone other than the stack also gets
only one answer. This answer is «yes» if performing the analogous positive comparison would
return a «no» answer.
708.6c
If an effect performs a comparison involving multiple characteristics of one or more split
cards in any zone other than the stack, each characteristic is compared separately. If each of the
individual comparisons would return a «yes» answer, the whole comparison returns a «yes»
answer.
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 the game sees its converted mana cost as “1, and 4.” The same is true if the
player chooses 4. If the player chooses 5, however, Assault/Battery would be unaffected.
708.7.
If an effect instructs a player to name a card and the player wants to name a split card, the player
must name both halves of the split card. An object has the chosen name if it has at least one of the
two names chosen this way.