Forum:? atk?

I have always thought that a ? attack is 0 when in the deck or hand. When its on the field its effect gives it an attack. And most monster with ? attacks have no original attack, there for cards based on original attack do not help. But i just found out a elemental searcher can not bring out King of the Skull Servants because he has a ? attack. Does that mean that ? attack make's his attack to were it cannot be identified until the monster is summoned so an elemental searcher requirement for a 1500 or less attack can not be used to take it out?