If you play Stacked Deck during a showdown while defending and reveal Nocturne, can you play him to the contested battlefield or does he have to go to your base?

Ruling: You can play Nocturne to the battlefield you're defending, as long as you control it, which you almost always do when defending.

Nuances:

• There are rare cases where you defend but don't control the battlefield, such as when your opponent moves to an open battlefield and you use Ride the Wind to move into the same battlefield (sometimes called "Surprise Defense"). In those cases, you would not be able to play Nocturne to that battlefield.