Chess glossary

An adjournment pauses an unfinished game for resumption later: the player to move writes a sealed move, it goes into an envelope, and play resumes from that position another day.

Armageddon is a tiebreak game that cannot end level: White gets extra time, and Black advances if the game is drawn.

Castling is a single move where the king and a rook move at once: the king steps two squares toward a rook, and that rook hops to the king’s other side.

Check is when your king is under direct attack, and you must answer it immediately on your next move.

Checkmate is when a king is in check and has no legal way to escape — it ends the game immediately, and the side delivering it wins.

A dead position is one where no sequence of legal moves could ever produce checkmate for either side. The game is drawn the moment such a position arises.

A draw is a tied game in which neither player wins; each side scores half a point.

A draw offer is a proposal to end the game as a draw. The correct procedure: make your move, offer the draw, then press your clock. The offer stands until your opponent accepts, declines, or moves.

En passant is a special pawn capture: a pawn that has just advanced two squares can be taken by an enemy pawn beside it, as if it had moved only one.

The fifty-move rule lets a player claim a draw if 50 moves by each side have passed with no capture and no pawn move.

An increment is bonus time, usually a few seconds, added to your clock after every move you make.

Insufficient material is an automatic draw that occurs when neither side has enough pieces to possibly deliver checkmate.

J'adoube is French for 'I adjust': announce it before straightening a piece on its square, and the touch-move rule does not apply to that touch.

Promotion is when a pawn reaches the opponent's back rank and is immediately replaced by a queen, rook, bishop or knight of the same colour.

Resignation is conceding the game: a player who resigns loses immediately. It is usually announced verbally or by stopping the clocks; tipping over the king is the traditional gesture.

Stalemate is when the side to move has no legal move but its king is not in check — the game is an immediate draw.

Threefold repetition is a draw rule: if the exact same position occurs three times in a game, with the same player to move, a draw can be claimed.

A time control is the clock setting for a game: how much total thinking time each player has, plus any increment per move.

The touch-move rule says that if you deliberately touch one of your pieces you must move it, and if you touch an enemy piece you must capture it, whenever a legal move or capture exists.

Alekhine's Gun is an attacking formation in which both rooks are doubled on a file with the queen stacked behind them, creating a battery that overwhelms any single defender.

Anastasia’s Mate is a pattern where a knight and a rook combine to mate a king pinned against the edge of the board, usually the h-file.

Anderssen's mate is a checkmate on the eighth rank in which the mating rook or queen on the corner square is supported diagonally, classically by a pawn on g7.

The Arabian Mate is a classic pattern in which a knight and a rook combine to checkmate a king trapped in the corner of the board.

Attraction is a tactic, usually a sacrifice, that forces an enemy piece or king onto a specific square where a follow-up blow wins the game or decisive material.

A back-rank mate is checkmate delivered by a rook or queen along the king’s back rank, where the king is boxed in by its own unmoved pawns and can’t escape.

A battery is two pieces of the same colour stacked on one line — file, rank, or diagonal — so they support each other and bring doubled force to bear.

Blackburne's mate is a rare pattern in which both bishops and a knight combine: the light-squared bishop mates on h7, the knight guards it, and the dark-squared bishop rakes the long diagonal.

The blind swine mate is delivered by two rooks doubled on the seventh rank: they devour the pawns in front of the castled king and then mate it in the corner.

Boden’s Mate is a pattern where two bishops on crisscrossing diagonals deliver checkmate to a king hemmed in by its own pieces, usually after queenside castling.

A clearance sacrifice gives up material to vacate a square, file, or diagonal so that another of your pieces can occupy or sweep through it with decisive effect.

A combination is a forced sequence of moves — usually built around a sacrifice — that leads to a concrete gain such as checkmate or winning material.

The corner mate is a checkmate in which a knight delivers the final blow to a king stuck in the corner, with a rook sealing the adjacent file and the king's own pawn blocking its head.

Damiano’s Mate is a pattern where a queen, supported by a pawn, delivers checkmate on the edge file — typically the h-file — often after a rook sacrifice clears the way.

A decoy lures an enemy piece — frequently the king — onto a particular square, usually with a sacrifice, so it can then be forked, checked, or mated.

A deflection forces an enemy piece away from an important defensive job, usually with a check or threat it must answer, so the thing it was guarding falls.

A desperado is a piece that is already doomed and so captures as much material as it can — or sells itself for the best price — before it is inevitably lost.

A discovered attack is when you move one piece out of the way so that a different piece behind it suddenly attacks an enemy target.

A double attack is any single move that creates two threats at the same time, so the opponent can parry only one of them.

A double check is a special discovered check where the moving piece and the piece it unveils both give check at the same instant.

The Dovetail Mate, also called Cozio’s mate, is a queen checkmate where the king’s two diagonal escape squares are both blocked by its own pieces.

The Epaulette Mate is a pattern in which a king is checkmated while flanked on both sides by its own rooks, which block the only squares it could escape to.

Fool’s Mate is the fastest possible checkmate in chess, delivered by Black on the second move after White fatally weakens the squares around their own king.

A fork is a single move that attacks two (or more) enemy pieces at once, so the opponent can only save one.

Greco's mate is a checkmate delivered by a rook or queen on the open h-file, with a bishop covering g8 and the defender's own g-pawn shutting the king in.

The Greek Gift is a bishop sacrifice on h7 (or h2 for Black), giving up the bishop with check to drag the castled king out and launch a mating attack.

The Hook Mate is a pattern using a rook, a knight, and a pawn together, with one of the enemy’s own pawns blocking the king’s last escape square.

Interference is a tactic where you place a piece on the line between two enemy pieces, breaking the defence or communication that runs along it.

The kill box mate is a rook and queen checkmate in which the rook checks next to the king and the queen supports it from one empty square away on the diagonal, forming a 3 by 3 box.

A king hunt is a sustained series of checks and threats that drags the enemy king out of its shelter and drives it across the board, usually ending in mate or decisive material gain.

Lolli's mate is a checkmate against a fianchettoed king in which a pawn wedged on f6 supports a queen that mates on g7.

Mayet's mate is a checkmate in which a rook mates on the corner square h8, protected from capture by a distant bishop on the long diagonal.

Morphy's mate is a checkmate where a bishop strikes the cornered king along the long diagonal while a rook controls the adjacent file and the king's own pawn blocks its last square.

The opera mate is a back-rank checkmate in which a rook, protected by a bishop on the diagonal, mates an uncastled king that is boxed in by its own pieces.

Overloading is when a single enemy piece is responsible for two defensive duties at once, so taking one job away lets the other collapse.

A pawn storm is the advance of two or more pawns toward the enemy king, aiming to trade themselves off and rip open files for the pieces behind them.

Pillsbury's mate is a checkmate in which a rook mates down the open g-file while a bishop on the long diagonal covers the corner escape square.

A pin is when a piece can’t move (or shouldn’t) because a more valuable piece sits directly behind it along the line of attack.

Removing the defender means capturing or trading off the piece that guards a target, so that the target is left undefended and can be taken.

The Réti mate is a checkmate in which a bishop, protected by a rook or queen, mates a king whose escape squares are all occupied by its own pieces.

A rook lift moves a rook vertically to the third or fourth rank and then sideways in front of its own pawns, bringing it into the attack without opening any files.

A sacrifice is deliberately giving up material — a pawn, a piece, or more — in return for something worth even more, such as a mating attack, a winning position, or material won back later.

A skewer is a pin in reverse: a valuable piece is attacked in front and must move, exposing a piece behind it on the same line.

A smothered mate is a checkmate delivered by a knight against a king that is completely hemmed in by its own pieces and so has no square to flee to.

The suffocation mate is a checkmate in which a knight attacks the king while a bishop (or queen) takes away the remaining escape squares from a distance.

The Swallow’s Tail Mate, also called the guéridon mate, is a queen checkmate where the king’s two rear escape squares are blocked by its own pieces.

A trapped piece is one that has no safe square to move to and is about to be captured, because every escape leads to it being taken.

Undermining is attacking the pawn or piece that supports an enemy structure, so that once the support is removed the thing it was defending becomes weak or falls.

The Vukovic mate is a checkmate in which a protected rook mates the king on the edge of the board face to face, while a knight covers the remaining escape squares.

A windmill is a tactic where a piece swings back and forth giving discovered check each way, forcing the king to dodge while a rook gobbles material every cycle.

An x-ray is when a long-range piece exerts its influence through an enemy piece along a rank, file, or diagonal, attacking or defending what lies beyond it.

A zwischenzug, or in-between move, is a surprise move (often a check or a stronger threat) inserted before the reply your opponent is expecting.

A backward pawn is one that has fallen behind the pawns beside it and can’t safely advance, leaving it stuck — often on a half-open file where it becomes a target.

A bad bishop is one whose own pawns are fixed on the same colour squares it travels on, blocking its diagonals and leaving it passive.

The bishop pair is the advantage of having both of your bishops while the opponent has only one (or none), since together they cover squares of both colours.

A blockade is placing one of your pieces directly in front of a passed (or isolated) pawn so it can’t advance, while your piece sits safe behind it.

Calculation is the concrete work of analyzing specific move sequences in your head: I go here, they go there, and evaluating the resulting positions.

Candidate moves are the small set of plausible moves you shortlist in a position before calculating any single line deeply.

Centralization is placing your pieces toward the middle of the board, where they control the most squares and can switch quickly to either wing.

A closed position is one where interlocked pawn chains block the center, shifting play to the wings and favoring knights and long-term maneuvering.

Compensation is the non-material value, such as activity, structure, initiative, or king safety, that justifies being behind in material.

Connected passed pawns are two passed pawns on adjacent files; because they can defend each other as they advance, they are extremely hard to stop.

Rooks are connected when they stand on the same rank with no pieces between them, so each defends the other, usually on the first rank after development.

Development is the process of bringing your pieces off their starting squares to active posts in the opening, getting ready to castle and fight for the centre.