Forum:Why do face-down Xyz monsters keep their materials?

Think about it, Equip cards are considered to be unusable on face-down monsters, because they have "unknown" stats and the equip cards are removed from the field if an equipped monster is turned face down due to this reason. You cannot use the effects of monsters or use the effects of cards that specify information from them (for instance, Dark Magic Attack cannot be used with a face-down Dark Magician) while they are face-down because they are not considered public knowledge, even if it was Book of Moon'd 2 seconds ago. You cannot stop a Tribute Set of a DARK monster while your opponent has 2 LIGHT monsters on the field to tribute while Gozen Match is on the field, because you're not supposed to be aware of its Attribute, even if you are using Respect Play. So why is it that when Xyz monsters are flipped face down, it must be considered a card that can have Xyz materials, and therefore, is an Xyz monster? Are there cards that specify face-down Xyz monsters for their effects or something? Tenebrae Candidae (talk • contribs) 10:14, July 19, 2013 (UTC)