Skewer

The skewer is the pin's mirror. Where a pin is "low-value piece in front of high-value piece," a skewer is "high-value piece in front of low-value piece." When the front piece moves to escape attack, the back piece becomes a target. Capturing the attacker or blocking its line may still defend the position; the alignment alone does not guarantee a material gain.

This is a real game (White to move). Bg4+ checks the king on e6, and on the same diagonal (g4-f5-e6-d7) behind the king sits a black rook on d7 - the valuable king in front (e6), the less valuable rook behind (d7), a textbook skewer (the arrow runs through the king to the rook behind it). The king must step out of check (...Ke5), and White then plays Bxd7 to win the rook at the end of the diagonal. Step forward (▶) to follow it. (A pin is the reverse: the cheaper piece sits in front.)

No capturesMaterial equal

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No capturesMaterial equal

33. Bg4+(1/3)

How often does it show up

Of the 212,300 puzzles in this site's database, 5,183 (2.4%) carry the skewer tag. 73.7% are tagged endgame, compared with 25.0% middlegame. Open files, ranks, and diagonals are often easier to find after pieces leave the board, which is consistent with the endgame share. The aggregate tags do not prove why the pattern is concentrated there, and a skewer can also appear in the middlegame or involve valuable pieces other than a king or queen. A practice set drawn from this database should nevertheless include plenty of endgame positions.

Skewer puzzles also tend to be rated low: 35.7% sit below rating 1200 against 22.3% above 1900. The pin, which skewers are usually taught next to, runs the other way at 12.5% below 1200 and 33.6% above 1900. Same geometry, opposite ends of the difficulty range.

What a Skewer Is

A skewer happens when two enemy pieces are aligned on the same line (file, rank, or diagonal), the front piece is more valuable, and a long-range piece (bishop, rook, queen) attacks the front piece. Moving the front piece exposes the back piece; calculate the defense before claiming a material gain.

Typical targets are king + queen alignment (check the king to target the queen behind) and queen + rook alignment (attack the queen to target the rook behind).

Pin vs Skewer - Mirror Tactics

The geometry is identical: same line, same long-range attacker. Only the order of values differs, and at a glance the two patterns look alike, so ask first which of the two pieces is more valuable.

Why Skewers Get Missed

Skewers are often missed even when players spot pins easily. Reasons:

1. When the front piece is the king, the move starts as a check - the player focuses on dealing with the check and doesn't simultaneously see "if the king moves, the queen falls."
2. Most teaching material is pin-centric - players see line-aligned pieces and think "pin" automatically, missing the skewer interpretation.
3. Skewers usually start with long-range bishop checks or rook file attacks - if the player misses these long-range threats during board scans, the skewer is invisible.

Signs a Skewer May Be Available

Watch for these signs.

1. Enemy king is exposed with a queen or rook on the same line behind it - the classical skewer pattern. A check can force the king aside, and then the queen or rook behind it becomes the target.
2. Enemy queen and rook are on the same file or rank - attacking the queen can win the rook, but check first whether the opponent can capture the attacker or counterattack.
3. In the endgame, enemy king and a pawn share the same file - a rook check can skewer the king and the pawn, stopping the promotion.
4. An empty diagonal after castling - a bishop on that diagonal can skewer king + a back piece.

Example: Rook Skewer - Endgame Signature

A common rook-skewer pattern from endgames. Black's king and pawn stand on the same a-file, and the white rook has just checked from a1. Step through with ►:

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The rook attacks the king along the a-file, and the a7-pawn sits behind the king on that same line. The check forces the king aside - 1...Kb3 - and 2.Rxa7 collects the pawn behind it. No king move could both escape the check and defend a7.

A rook, plus an enemy king and pawn lined up on the same file - that combination is the rook-skewer signature, and one reason rook-versus-king-and-pawn endgames are so awkward to defend.

How to Defend Against a Skewer

When a skewer is threatened, there are three defenses.

1. Move the front piece (king or queen) off the line in advance - break the alignment before the attack lands.
2. Interpose another piece - block the line, protecting the back piece.
3. Capture or chase the attacking long-range piece - eliminate the attacker.

Trace the line from the attacker. Black rook e8 → White queen e2 → White king e1 is an absolute pin, not a skewer. White is not in check, but the queen cannot leave the file and expose its king. A pinned piece can still move along the pin line: Qxe8+ is legal, but the d8-king recaptures, so it only gives up the queen for a rook.

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In the comparison position the order is reversed: Black rook e8 → White king e4 → White queen e1. White is in check, and wherever the king steps, for example Kd3 Rxe1, the rook takes the queen and the king is too far away to recapture. That is the skewer. However, Be5 is also a legal block, and after Rxe5+ Kxe5 White has traded a bishop for the rook. Neither a king move nor losing the queen is forced just because a skewer alignment exists.

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Checklist

Quick scan for "is there a skewer available?":

• Are two enemy pieces on the same line (file, rank, or diagonal)?
• Is the front piece more valuable? (A king in front always makes it a skewer. A queen in front does too, unless the piece behind is the king.)
• Can my bishop, rook, or queen reach that line?
• Once the front piece moves, will the back piece actually fall? (Is it undefended?)

Related Tactics

• Pin - same geometry, opposite roles. In this database skewer puzzles are rated lower than pin puzzles (35.7% below 1200 against 12.5%), so the pin does not have to come first.
• Discovered Attack - another tactic exploiting line alignment.
• Fork - single piece attacking two targets. A skewer sometimes leads into a fork: 167 skewer puzzles (3.2%) also carry the fork tag.

FAQ

Q. Fastest way to tell pin from skewer? "Whichever of the two pieces is more valuable: in front → skewer, behind → pin." That one sentence settles most of them. Whenever you see two pieces aligned, ask immediately which side is more valuable.

Q. Can a rook skewer a rook? Two rooks can line up under attack too, but the typical skewer described here has the more valuable piece in front. In either case, check whether the capturing rook can itself be recaptured: two rooks being the targets does not automatically make the sequence an equal exchange.

Q. What is a good way to learn skewers? Practice king + queen skewer puzzles (bishop or rook attacker, either works), then queen + rook skewers, finally endgame rook skewers. Repeat until line alignment + "valuable in front" recognition feels automatic.

Q. Why is a skewer sometimes called an "X-ray attack"? In English chess writing, X-ray is a metaphor for "an attack that passes through a piece to reach what stands behind it," and skewers, discovered attacks, and pins are sometimes loosely called X-rays as well. This site, following Lichess puzzle themes, tracks X-ray attack as a separate motif from the skewer. "Skewer" is the standard term for the pattern on this page.

References

• Lichess, puzzle theme Skewer (the source of this site's puzzle tags). https://lichess.org/training/themes
• Statistics produced by scripts/analyze-theme-stats.mjs --theme skewer; the run is recorded in docs/data/skewer-stats.md.

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On Chess Motif Stats, the skewer is tracked as one of 53 separate motifs. When signed in, SM-2 calculates a review date per motif to guide selection. Recently attempted puzzles are excluded first, but the same puzzle may return when the available pool is too small. Practice recognizing the relationship, rather than memorizing one answer.

Start training: Skewer Training

Related: Pin · Discovered Attack · All tactics