
Black to Play
Solution below ↓
Solution

Tactical Motif: Skewer
A skewer is a tactical idea where you attack a valuable piece, but if it moves, it exposes another piece of equal or lesser value behind it.
1…Rg4+ forces the white king to move, after which Black will capture the undefended rook on c4.
1…Kxa7 also wins material, but 1…Rg4+ wins more.