A confidence trick is the use of confidence by someone when answering a question, and because of the confidence they evoke in the other person the answer is determined to be true. A good confidence trick can make anyone believe (nearly) anything because of the confidence the other person exudes whether it is true or false. The use of a confidence trick is used most by highly intelligent people because you need to be witty and the fact that you are playing off of what the person knows, and can know.
(After sneaking into the gym of an apartment that one does not live in)
Worker- "Do you live in this apartment complex because in order to use the gym you must live her?"
(True name)Brad(All said in perfect vocal pitch)"Yes I live in apartment 2234(a true apartment, though not his), my name is Joey Mathers (fake name) I don't have my keys because my friend just went back to the apartment to get his running shoes"
Worker- (After seeing the confidence the person is exuding and deciding its not worth it to check the computer) "Ok Joey thank you"
Brad-"No thank you!"