X-Ray Attacks in Chess
An x-ray attack (also called an "x-ray") is a tactical pattern where a piece attacks or defends through another piece that stands on the same line. It is one of chess's most subtle tactical themes.
How it works
An x-ray occurs when a long-range piece (queen, rook, or bishop) exerts influence on a square behind an intervening piece. The attacking piece "sees through" the blocking piece. This can create tactical threats that are invisible at first glance.
X-ray defence
An x-ray can also be defensive: a piece on a back rank can protect a piece on a forward rank "through" another piece. If the intermediate piece is captured, the x-ray piece immediately takes over the protection.
In combination with other tactics
X-rays frequently combine with skewers and pins. A skewer is essentially a forced x-ray: you attack a valuable piece that must move, revealing the target behind it. Recognising x-ray patterns is a sign of intermediate to advanced tactical vision.
Solve x-ray attack puzzles to train this pattern directly.