Over 5 years ago( the picture of me and the bunny is way beyond 5 years) I put out a project called MENTAL. It was some of the most powerful and visual card magic I had created up till then. One of those effects was a gem called SPEECHLESS. I have since UPDATED it with not 1 BUT 2 versions where you can now do this with a borrowed deck, no deck setup.
Here is the effect:
A deck of cards is FAIRLY shuffled by your audience. 2 cards are selected and the values added up. Let's say the value is 5, It can be any number, (3 of spades and 2 of diamonds for example). When the card box is turned over there is a small post it note stuck to the case. They FAIRLY take the post it and open it to reveal the RANDOM number the cards added up to. As a kicker. A random card is generated by them using the valued cards. Let's say 5 of spades (free choice).The box is opened up to find one single card, yep you guessed it..it is THEIR FREELY GENERATED CARD!
This is a mental miracle that will take them beyond SPEECHLESS...THEY WILL BE COMPLETELY SILENT!