?

? usually signals an unknown ATK, DEF or Level value.

If a Monster's ATK of DEF is represented as a '?' on the card, it cannot be searched from the Deck using the relavant value, since it does not have a value whilst in the Deck.

If a monster has ? ATK or DEF value, and the effects that determine the ATK and DEF cannot be activated, the ?'s on it's values are treated as 0's.

Cards that search for monsters with less ATK than a particular value, such as Sangan, cannot get monsters with ? ATK.