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Chess Tactics Glossary: Forks, Pins, Skewers and More

Strategy is what you plan over twenty moves; tactics are what win material in two. Studies consistently show that games between improving players are decided overwhelmingly by tactics — spotting them and not falling into them. Here is the vocabulary, in plain language.

Fork

One piece attacks two or more targets at once. The victim can only save one. Knights are the fork champions — their weird movement lets them attack a king and queen simultaneously without either being able to hit back (the royal fork, chess's lottery jackpot). But every piece forks: pawns fork two minor pieces, queens fork king and loose rook constantly.

Pin

A piece can't move — or really shouldn't — because a more valuable piece stands behind it on the same line. A bishop pinning a knight to the queen makes that knight a statue. When the piece behind is the king, it's an absolute pin and moving the pinned piece is actually illegal. Pinned pieces are targets: pile attackers onto them, because they can't run.

Skewer

The pin's reverse: the more valuable piece stands in front and is attacked first. It must move, exposing the piece behind it to capture. Rook checks that then scoop up a queen or rook behind the king are the everyday version.

Discovered attack

You move one piece and unmask an attack from another standing behind it. The beauty: the moving piece can make its own threat at the same time, creating two threats with one move. When the unmasked attack is a check — a discovered check — the moving piece can grab almost anything with impunity.

Double check

The rarest and most violent tactic: the moving piece and the unmasked piece both give check. Blocking is impossible and capturing one attacker still leaves the other — the king must move. Many brilliant mating combinations run on double check.

Deflection and decoy

Twins with opposite jobs. Deflection drags a defender away from its post (sacrifice a rook to pull the queen off the back rank, then mate). A decoy lures a piece onto a poisoned square (sacrifice to pull the king onto a square where a knight fork awaits).

Removing the defender

If a piece is guarded by exactly one defender, capture or chase the defender — the piece falls next move. Simple bookkeeping that wins material at every level of play.

Zwischenzug (the in-between move)

German for "in-between move": instead of the expected automatic recapture, you first play a bigger threat — usually a check — and only then recapture. The move your opponent didn't budget for.

How to actually learn these

Reading definitions plants the seed; repetition grows it. In your own games, after every enemy move, scan: are any of my pieces forkable, pinnable, or loose? "Loose pieces drop off" is half of practical chess. Then play — tactics come to those who look for them, and every game on ChessDuel is free practice.