Split cards

[Rass]

{run} how do these work? Can you only cast one. Can you cast both. If you can cast both but only cast one does it go to the graveyard. And what's the mana cost on this card both or pick one?  Thanks

[Thattallguy]

The way I understand it. You cast one side of the card. The other side goes into the GY. However if you have the mana available you can cast both.

[BlackJester]

Split cards, as they are called, can have one side cast at a time. When you cast it and put it on the stack, it is like the other side doesn't exist.

[Rass]

So you can only cast one side? And what would you consider the casting cost if you had to clash with someone? And thanks for the heads up I quit in 3rd edition so a lot of this stuff is new to me.

[BlackJester]

So you can only cast one side? And what would you consider the casting cost if you had to clash with someone? And thanks for the heads up I quit in 3rd edition so a lot of this stuff is new to me.

No worries. Split cards have their own section in the rules (708).

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).

So if you clash and reveal Assault // {Battery}, the game would see a CMC of both 1 and 4. So your opponent would have to beat 4 to win the clash, since 5 would beat 4 and 1.