6 Discovered attack
The discovered attack is a special form of the double attack. A piece moves and either attacks or takes something. At the same time it opens up a line along which another piece is threatening. Only one of the threats can be parried and usually material is lost.
Move directly on the board to input a solution. Either click first on the start square and then on the target square. Or click on the piece, hold on to it, move it tot he target square and let go of it. The button ‘Left arrow’ takes back the move.
The discovered attack is a clever tactic which wins material. A piece is blocking a line of attack between two other pieces. It moves and in doing so sets up two threats at once. Only one of these can be parried..