ChessA skewer is attacking a valuable piece along a line, waiting for it to move, then taking the piece behind it. It's the opposite of a pin. In a pin the front piece doesn't dare move; in a skewer the front piece has to move. When you play free chess, a king in check or a queen under attack is often where a skewer begins.
What it looks like
The most common skewer is a check from a rook or queen with a queen or rook standing right behind the king.
Black is in check and has to save the king first. No black piece can block on b5 or c5, so the king has to leave the 5th rank, and then the rook slides along the rank and takes the queen on h5.
Which pieces skewer best
Rooks and queens: files and ranks
Rooks and queens travel a long way along files and ranks, so they make the "check, then grab the queen" skewer most easily. In the endgame the king often walks into the middle of the board, so be extra careful about your pieces lining up with your king.
Bishops and queens: diagonals
Bishop skewers are harder to spot, because diagonals are harder to see at a glance.
The black king has to get off that diagonal (it can't go to c6 or e4, which are still on the bishop's line), and then the bishop takes the rook on b7.
Knights and pawns can't skewer, because they can't attack "through" one piece to the square behind it.
A real example: a skewer during promotion
In endgames where both sides race to promote, skewers come up a lot. Here the black pawn promotes first and seems to keep things level, but the black king is on the wrong square:
The black king on e4 sits right in the middle of the long a8-h1 diagonal. If it had stepped off that line before promoting, there would be no skewer. In a promotion race, always ask first: will the square where my opponent promotes look straight at my king and queen?
How to defend
- Don't line your king up with your queen or rooks. This matters most in the endgame, when the king wanders around the middle and easily ends up on a line with its own big pieces.
- When you're in check, pick a square that doesn't expose the piece behind. Sometimes blocking the check with a piece is better than moving the king.
- Protect the piece behind. If the skewered piece is protected, taking it is only a trade.
- Watch which lines the enemy rooks and bishops can reach. Before you finish each move, glance at your opponent's long-range pieces.
Practice puzzles
Show answer
1. Ra6+ The rook goes to a6 with check. No black piece can block on b6, so the king has to leave the 6th rank, and next move the rook takes the queen on g6 along the rank.
Show answer
1. Qd4+ The queen goes to d4 with check on the diagonal. The black king has to leave the diagonal (g7 is still on it, so not there), and then the queen takes the rook on h8.
Show answer
1. Bc3+ The bishop goes to c3 with check. The black king can't block or capture the bishop, so it has to move, and the bishop takes the rook on h8 along the long diagonal.
FAQ
What's the difference between a skewer and a pin?
Both are "two pieces, one behind the other, on a line." The difference is the front piece. If the front piece is worth less and doesn't dare move, it's a pin. If the front piece is worth more (like the king or queen) and has to move, so the piece behind gets taken, it's a skewer.
Does a skewer have to be a check?
No. Attacking a queen with a rook behind it is also a skewer: the queen will surely move, and you get the rook. But a skewer with check is the strongest, because your opponent has no choice at all.
Why is it called a skewer?
Like a kebab skewer, one stick runs through the front piece and the back piece together.
Try it yourself
Skewers and pins are a pair, so it's best to learn them together. You can also go back to chess tactics for the other tactics. Then play chess vs the computer, and in the endgame pay special attention to whether your king and big pieces have lined up.