Simplicity itself, with IMPACT! The KING of packet tricks! This will become a pet effect, carrying it with you at all times!
Effect:
The performer (that's YOU!) pulls a small envelope from his/her pocket, stating that there is ONE (and ONLY ONE) King reversed among the other three in the envelope.
This envelope is placed on a nearby table where it remains in full view for the duration of the effect.
A spectator is then asked to think of one (and ONLY ONE) King: the King of Spades, Clubs, Diamond, or Hearts. You ask them to now reveal the identity of the King. Let's say they choose the King of Diamonds.
You immediately open the small envelope, removing four (and ONLY FOUR) cards; the spectator can examine the envelope for duplicates if they want.
You then spread out the four cards to reveal that the KING OF DIAMONDS is the ONLY face-up King in the packet! If that weren't enough, you remove the card, turning it over to show that IT IS ALSO THE ONLY BLUE-BACKED CARD AMONG THE RED-BACKED CARDS!
This envelope is placed on a nearby table where it remains in full view for the duration of the effect.
A spectator is then asked to think of one (and ONLY ONE) King: the King of Spades, Clubs, Diamond, or Hearts. You ask them to now reveal the identity of the King. Let's say they choose the King of Diamonds.
You immediately open the small envelope, removing four (and ONLY FOUR) cards; the spectator can examine the envelope for duplicates if they want.
You then spread out the four cards to reveal that the KING OF DIAMONDS is the ONLY face-up King in the packet! If that weren't enough, you remove the card, turning it over to show that IT IS ALSO THE ONLY BLUE-BACKED CARD AMONG THE RED-BACKED CARDS!