Checkmate patternsRéti's mate
Named after Richard Réti, who finished his famous game against Tartakower (Vienna, 1910) with it. A bishop checks right beside the king, with a rook guarding it.
How it works (spoiler)
The bishop checks from the square right next to the king, and the rook behind it on the same open file protects it, so the king cannot take it. The rook also covers the file beside the king, the bishop’s diagonal runs on through the king, and the king’s own pieces block the rest.