Chess glossary

The piece the whole game is about. It steps one square in any direction, can never move into check, and can never be captured — the game ends when it has no legal escape.

The strongest piece: it moves any distance along a rank, a file or a diagonal. Worth roughly nine pawns.

Moves any distance along a rank or a file. Worth roughly five pawns, and strongest on open files and the seventh rank.

Moves any distance along a diagonal, so it never leaves the colour of square it starts on. Worth roughly three pawns.

Moves in an L — two squares one way, one square across — and is the only piece that jumps over others. Worth roughly three pawns.

Moves one square forward (two from its starting square) but captures diagonally. It cannot move backwards, which is why every pawn move is permanent.

Any of the six kinds of man on the board. In conversation, "piece" often means everything except a pawn — "I won a piece" means a knight or a bishop, not a pawn.

One of the sixty-four cells, named by its file and rank: e4, g7, a1.

The eight-by-eight grid. It is set up with a light square in each player's bottom-right corner.

A column of eight squares, named a to h from White's left.

A row of eight squares, numbered 1 to 8 from White's side.

A slanting line of same-coloured squares — the bishops' and the queen's highways.

The player who moves first, and the pieces they command.

The player who moves second.

One player's turn. A "move" in notation usually means both players' turns — 1.e4 e5 is move one.

Taking an enemy man by moving onto its square. The captured man leaves the board.

A direct attack on the king. The player in check must answer it immediately: move the king, block the line, or capture the attacker.

A check with no legal answer. The game ends at once, and the player delivering it wins.

Short for checkmate.

The player to move has no legal move and is not in check. The game is a draw, however much material either side has — which is why a winning position still needs care.

A game that ends level: by stalemate, agreement, threefold repetition, the fifty-move rule, or insufficient material.

To concede the game rather than play a lost position out.

The one move that shifts two pieces: the king steps two squares towards a rook and that rook jumps to the far side of it. Legal only if neither piece has moved, the squares between are empty, and the king is not in check or passing through one.

Castling towards the h-file, written O-O. The short, common one.

Castling towards the a-file, written O-O-O. Three squares must be clear instead of two.

What happens when a pawn reaches the far rank: it becomes a queen, rook, bishop or knight of its own colour. The choice is the player's, and it is not limited to pieces already captured.

Practise it: 12 positions

To carry out a promotion.

A pawn that has just advanced two squares may be captured, on the very next move only, by an enemy pawn beside it — as if it had advanced one.

One move that attacks two targets at once. Knights fork most often, but every piece can.

Practise it: 12 positions

A piece that cannot move without exposing something more valuable behind it. A pin against the king is absolute — moving is illegal, not just costly.

Practise it: 12 positions

The reverse of a pin: the valuable piece is in front and must move, so the one behind it falls.

Practise it: 12 positions

Moving one piece so that the piece behind it attacks along the opened line. The moving piece can create a second threat of its own.

Practise it: 12 positions

A discovered attack where the opened line gives check.

Check from two pieces at once, produced by a discovery. It cannot be blocked or answered by a capture — the king must move.

A player's own first rank, where the king usually sits after castling.

Mate delivered by a rook or queen on the back rank, against a king shut in by its own unmoved pawns.

Practise it: 12 positions

A square the king can legally move to. Making one — often by pushing a pawn in front of a castled king — is the standard cure for a back-rank weakness.

A piece with no defender. Loose pieces are what tactics feed on.

A loose piece that is also attacked, and can simply be taken.

Practise it: 12 positions

Guarded by another of your men, so a capture can be answered by a recapture.

Not guarded by anything.

To threaten to capture something, or a sustained campaign against a target such as the enemy king.

Something you intend to do next move that your opponent has to answer.

To guard a man or a square, or to answer a threat.

A move that throws away material or the game — usually by missing a one-move tactic rather than by deep miscalculation.

Giving up material on purpose for something worth more: an attack, a promotion, a mating net.

Practise it: 12 positions

Exchanging a man for one of similar value.

A trade. "The exchange" specifically means a rook for a knight or bishop — winning the exchange is winning a rook for a minor piece.

The total value of the men you have. Counting it before and after a capture is the habit that prevents most blunders.

Bringing pieces off their starting squares to squares where they do something. The opening is largely a race to develop.

The four central squares, and the wider zone around them. Pieces in the centre reach more squares, so control of it decides most openings.

The first phase, roughly the first ten to fifteen moves: develop, take space in the centre, get the king safe.

The phase after development, where plans and tactics decide the game.

The phase where few pieces remain, the king becomes an attacker, and pawns become the point.

Kings facing each other with one square between them. The player who does not have to move controls the squares beyond — often the whole point of a pawn ending.

A pawn with no enemy pawn in front of it on its file or the files beside it. Nothing can stop it except pieces.

One move's worth of time. Gaining a tempo means making a threat that also advances your plan; losing one means moving the same piece twice for nothing.

A position where every legal move makes things worse, and the obligation to move is itself the problem. Almost always an endgame idea.

How exposed your king is. It is the one factor that outranks material, because losing the king ends the game.

A position that should be won with correct play. It is not a won game — stalemate, a back-rank mate or a single blunder can still take it away.

The scan to run before every move: your checks, your captures, your threats — and then your opponent's. Lesson 4 is built on it.

A move worth calculating. Listing two or three candidates before calculating any of them is how strong players avoid tunnel vision.

The rectangle a rook and king shrink around a lone enemy king. Each check makes the box smaller until there is no room left — the method in the rook-mate lesson.

Mate with two rooks (or a rook and queen) checking alternately along successive ranks, driving the king to the edge. Also called the staircase.

Mating a lone king with king and queen. The queen takes squares away, the king walks up, and stalemate is the only real danger.

Mating a lone king with king and rook. Slower than the queen mate, and it needs both pieces working together.