Wildcall

Because face-down creatures don't have names, they can't have the same name as any other creature, even another face-down creature.

2014-11-24

If a face-down permanent you control leaves the battlefield, you must reveal it. You must also reveal all face-down spells and permanents you control if you leave the game or if the game ends.

2014-11-24

Unlike a face-down creature that was cast using the morph ability, a manifested creature may still be turned face up after it loses its abilities if it's a creature card.

2014-11-24

You must ensure that your face-down spells and permanents can easily be differentiated from each other. You're not allowed to mix up the cards that represent them on the battlefield in order to confuse other players. The order they entered the battlefield should remain clear. Common methods for indicating this include using markers or dice, or simply placing them in order on the battlefield. You must also track how each became face down (manifested, cast face down using the morph ability, and so on).

2014-11-24