The book offers 100 puzzles with discovered attack and discovered check. Real chess games are used to create those puzzles. Please keep in mind that these are do-it-yourself exercises, therefore you must be familiar with all of the basic chess principles. When a player moves a piece out of the way to expose a previously blocked attack by another piece, this would be known as a discovered attack. In a discovered check, one piece moves, allowing a bishop, rook, or queen to open a line towards the opposing king.