All spells are cast facedown. Enchantments come into play sideways. Any time you can reveal an enchantment you can guess the name of a spell or object your opponent controls. Your opponent must reveal the card when you do this. If you guess right the card is unusable until the end of the round. If you guess wrong the opponent can switch out the card for another one in their spellbook that has the same spellbook cost, pay the difference in mana cost, and put it in play face up.
