In Wiretap each player constructs a 5x5 grid containing "wires," which are single, double, triple, and quadruple lines, exactly three spaces long. The grid must contain ten wires, one in each row and one in each column. A specific number of each type must be used.
A turn consists of each player simultaneously choosing a space to ask about; the opponent just reveals the number of wires in the selected space.
When a player thinks they can reoonstruct their opponent's grid they announce this. They win if they are correct or produce a grid with the same number of wires in every space as the correct grid. If they are incorrect their opponent gets a double victory if playing a series of games.
Variants are given for a 6x6 board and for using some longer wires.