Card Edge Message

The setup for this puzzle is a deck of cards spread out decoratively.

The cards look ordinary. The order may be conspicuous but has no special meaning. The players can pick up one of the cards and see nothing special about it.

The solution is simply to move the cards back into a stack. Once they do that, the players simply have to observe that there is a message or code written on the side of the stack.

This message is only visible when the cards are stacked in the correct order. The cards should be spread in the order they need to be in so players just need to scoop them up in a pile in the correct order. That said, you should make note of the correct order to help players arrange them back in case they happen to shuffle the cards before noticing the message on the side.