Chess glossary

Algebraic notation

The standard way of recording chess moves using letters (a-h) and numbers (1-8) for squares, plus piece letters (K, Q, R, B, N). See our full chess notation guide.

Annotation

Written commentary on a chess game, using symbols like !, ?, !!, and ?? to evaluate moves alongside explanatory text.

Attack

A move or sequence aiming to win material, deliver checkmate, or create lasting threats against the opponent's position.

Back rank

The first rank for White (rank 1) or eighth rank for Black (rank 8) — the row where the major pieces start.

Back-rank mate

Checkmate delivered by a rook or queen on the opponent's back rank when their king is trapped by its own pawns. See our back-rank mate guide.

Backward pawn

A pawn left behind its neighbors that cannot safely advance because the square ahead is controlled by enemy pawns. A long-term weakness.

Bad bishop

A bishop whose movement is blocked by its own pawns sitting on the same color as the bishop. Hard to activate.

Bishop

A minor piece that moves any number of squares diagonally. Worth approximately 3 points. Stays on its starting color forever.

Bishop pair

Having both bishops (one on light squares, one on dark squares) while the opponent does not. Generally considered worth about half a pawn extra.

Blitz

A fast time control, typically 3 to 5 minutes per player for the entire game.

Blockade

Placing a piece (often a knight) directly in front of an enemy pawn to stop it from advancing.

Blunder

A serious mistake that loses material, allows checkmate, or significantly worsens the position. Annotated with "??" in notation.

Book move

A move that follows established opening theory ("the book"). To be "out of book" means the players have entered unanalyzed territory.

Bullet

An extremely fast time control of 1 minute per player (or sometimes 2 minutes) for the whole game.

Calculation

The mental process of working out specific move sequences and their consequences several moves ahead.

Candidate move

A move you're considering during analysis. Strong players generate multiple candidates before calculating any of them.

Capture

Removing an opponent's piece from the board by moving your piece onto its square. Indicated by "x" in notation (e.g., Nxe5).

Castling

A special move where the king moves two squares toward a rook and the rook jumps over the king. The only move that involves two pieces. Notated O-O (kingside) or O-O-O (queenside).

Center

The four central squares: d4, d5, e4, e5. Controlling the center is one of the fundamental opening principles.

Check

A direct attack on the king. The player in check must respond on their next move. Notated "+".

Checkmate

A check that cannot be escaped — the king cannot move to safety, the check cannot be blocked, and the attacking piece cannot be captured. Ends the game. Notated "#".

Classical (time control)

A slow time control, typically 90+ minutes per player. The format used in world championship matches and major tournaments.

Closed file

A file with at least one pawn from each side on it. The opposite of an open file.

Closed position

A position with locked pawn chains and limited mobility for the pieces. Tends to favor knights over bishops.

Combination

A forcing sequence of moves, usually involving a sacrifice, that wins material or delivers checkmate by force.

Connected pawns

Two or more pawns on adjacent files that can defend each other. Stronger than isolated pawns.

Counterplay

Active play that creates threats of your own, distracting the opponent from their plan.

Dark squares

The 32 darker-colored squares on the chessboard, including a1, c1, e1, g1, b2, d2, f2, h2, and so on.

Decoy

A tactic that lures an enemy piece (often the king) to a specific square where it will be vulnerable to a follow-up attack.

Deflection

A tactic that forces a defending piece to abandon its post, leaving something else undefended.

Development

Moving pieces from their starting squares to active positions. One of the core opening principles.

Discovered attack

An attack revealed when one piece moves out of the way, uncovering an attack from a piece behind it.

Discovered check

A discovered attack where the unveiled attack delivers check to the enemy king. Especially powerful because the moving piece is free to do anything else.

Double attack

Two threats made simultaneously. The opponent can usually only address one.

Double check

A check delivered by two pieces at the same time (achieved through a discovered check). The king MUST move — blocking or capturing won't stop both checks.

Doubled pawns

Two pawns of the same color on the same file. Generally a structural weakness because they can't defend each other.

Doubled rooks

Two rooks of the same color stacked on the same file. Extremely powerful, especially on open files.

Draw

A game that ends without a winner. Can occur by stalemate, threefold repetition, fifty-move rule, insufficient material, or mutual agreement.

Elo rating

A numerical rating system for measuring chess ability, named after Arpad Elo. Used by FIDE and many online platforms. Ratings typically range from 400 (beginner) to 2800+ (world champion).

Endgame

The final phase of a chess game with few pieces remaining. Kings become active, pawns aim to promote, and small advantages decide everything.

En passant

French for "in passing." A special pawn capture where a pawn that moves two squares from its starting position can be captured by an enemy pawn as if it had moved only one square. Must be done on the next move or the right is lost.

En prise

French for "in take." A piece that is undefended and can be captured for free.

Exchange (the)

Winning a rook for a minor piece (knight or bishop) is "winning the exchange." Losing one is "losing the exchange." Worth about 1.5-2 points.

Exchange sacrifice

Deliberately giving up a rook for a minor piece in exchange for positional or tactical compensation.

Fianchetto

Italian for "little flank." Developing a bishop to b2, g2 (White) or b7, g7 (Black) — one square diagonally in from the rook. Common in many openings including the King's Indian and Catalan.

FIDE

Fédération Internationale des Échecs — the World Chess Federation, the governing body of international chess. Founded in 1924.

Fifty-move rule

A draw can be claimed if 50 consecutive moves by each side have occurred without any pawn move or capture.

File

A column on the chessboard, labeled a through h from White's left to right.

Flag (fall)

In timed games, when a player runs out of time, their "flag falls" and they lose (unless the opponent has insufficient material to checkmate, in which case it's a draw).

Fool's mate

The fastest possible checkmate in chess, in just 2 moves: 1.f3 e5 2.g4?? Qh4#. Requires White to play two terrible moves and is essentially never seen in real games. See our Fool's Mate page.

Fork

A tactic where one piece attacks two or more enemy pieces simultaneously. Most commonly delivered by knights.

Fortress

An endgame position that cannot be broken through, even with material disadvantage. The defender holds a draw by setting up an impenetrable formation.

Gambit

An opening that sacrifices material (usually a pawn) in exchange for development, initiative, or attack. The Queen's Gambit, King's Gambit, and Evans Gambit are well-known examples.

Good bishop

A bishop whose mobility is not restricted by its own pawns. Opposite of a bad bishop.

Grandmaster (GM)

The highest title FIDE awards (apart from World Champion). Earned through high-level tournament performance. About 2000 grandmasters exist worldwide.

Half-open file

A file with no friendly pawns but at least one enemy pawn. Valuable because the enemy pawn becomes a long-term target.

Hanging piece

A piece that is undefended and can be captured for free. Same as "en prise."

Hole

A square in your territory that can no longer be defended by a pawn, making it a potential outpost for the enemy.

Hypermodern

A school of chess thought (early 20th century) that advocates letting the opponent build a big center, then attacking it with pieces from the flanks. The King's Indian and Grünfeld Defense are hypermodern openings.

Initiative

Having the active, threatening position. The player with the initiative dictates the pace and creates problems for the opponent to solve.

Insufficient material

A position where neither side has enough material to deliver checkmate. Examples: king vs king, king and bishop vs king. Results in a draw.

International Master (IM)

The second-highest FIDE title after Grandmaster. Requires sustained strong tournament performance.

Interpose

To block a check by placing a piece between the checking piece and the king.

Isolated pawn

A pawn with no friendly pawns on adjacent files. Hard to defend, but the open files next to it can be useful for rooks.

J'adoube

French for "I adjust." Said before touching a piece to center it on its square, exempting the player from the touch-move rule. Must be said on your own turn.

King

The most important piece. Moves one square in any direction. The game ends when the king is checkmated. Notation letter: K.

Kingside

The half of the board containing the kings' starting squares (the e, f, g, h files).

Knight

A minor piece that moves in an L-shape (two squares one direction, then one perpendicular) and can jump over other pieces. Worth approximately 3 points. Notation letter: N.

Light squares

The 32 lighter-colored squares on the chessboard.

Long diagonal

One of the two longest diagonals on the board: a1-h8 or a8-h1. Fianchettoed bishops control these.

Lucena position

A famous winning rook-and-pawn endgame technique where the side with the extra pawn forces promotion using a "bridge" maneuver with the rook. See our rook endgames guide.

Luft

German for "air." A small escape square for the king, made by advancing one of the pawns in front of the castled king (usually h-pawn or g-pawn) to prevent back-rank mates.

Major piece

A queen or rook. Pieces with long-range straight-line movement.

Material

The pieces on the board. To be "up material" is to have more (or more valuable) pieces than the opponent.

Mate

Short for checkmate. The game-ending check that cannot be escaped.

Middlegame

The phase between the opening and endgame, characterized by tactical complications and strategic maneuvering. Most games are decided here.

Minor piece

A knight or bishop. Pieces worth approximately 3 points each.

Novelty

A new move in a known opening position, played for the first time in a high-level game. Notated as "N" in some game collections.

Open file

A file with no pawns on it. Highly valuable for rooks, which can sweep up and down without obstruction.

Open game

A position with few pawns blocking lines, allowing long-range pieces (especially bishops) to operate freely. Often arises from 1.e4 e5 openings.

Opening

The first phase of the game (roughly the first 10-15 moves), where players develop pieces and contest the center. See our openings library.

Opposition

A king-and-pawn endgame concept where kings face each other with one square between. The player NOT to move has the opposition and usually has an advantage.

Outpost

A square in or near enemy territory where a piece (usually a knight) is supported by a pawn and cannot be attacked by enemy pawns. Often game-winning when established.

Overloading

A tactic exploiting a defender that's responsible for too many duties. Attacking one of its responsibilities forces it to abandon another.

Passed pawn

A pawn with no enemy pawns ahead of it on its own file or on adjacent files. Has a clear path to promotion if no enemy pieces stop it.

Pawn

The least valuable piece (worth 1 point) but strategically vital. Moves forward one square, two on its first move, captures diagonally. Promotes when reaching the last rank.

Pawn chain

A diagonal connection of pawns where each defends the next. The base of the chain is typically the weakest point.

Pawn structure

The shape and pattern of pawns on the board. Permanent (pawns can't move backwards), so structure decides long-term strategic plans.

Perpetual check

A sequence of checks that can be repeated indefinitely, forcing a draw by threefold repetition. A common saving resource in lost positions.

Philidor position

The classic drawing technique for the defender in a rook and pawn vs rook endgame. The defending rook sits on the 3rd rank to prevent the attacking king's advance. See our rook endgames guide.

Pin

A tactic where a piece cannot move because moving it would expose a more valuable piece behind it. Absolute pins involve the king; relative pins involve other pieces.

Plan

A multi-move strategic idea, such as "attack on the queenside" or "trade the bad bishop." Distinct from move-by-move calculation.

Positional play

Long-term strategic play focused on piece placement, pawn structure, and small advantages. Opposite of tactical/combinational play.

Promotion

When a pawn reaches the opposite end of the board (rank 8 for White, rank 1 for Black), it must be replaced by a queen, rook, bishop, or knight.

Prophylaxis

Preventive moves that stop the opponent's plans before they can be executed. A hallmark of grandmaster-level play.

Queen

The most powerful piece. Combines the movement of rook and bishop — any number of squares in any straight line. Worth 9 points. Notation letter: Q.

Queenside

The half of the board containing the queens' starting squares (the a, b, c, d files).

Quiet move

A move that doesn't capture, check, or directly threaten anything — but still serves a deeper strategic purpose. Often the strongest moves in a position.

Rank

A row on the chessboard, numbered 1 through 8 from White's side.

Rapid

A time control between blitz and classical, typically 10 to 30 minutes per player.

Removing the defender

A tactic where you capture or chase away the piece defending an enemy target, leaving the target vulnerable to your next move.

Resign

To concede the game without playing it to checkmate. Common when a player sees the position is hopeless.

Rook

A major piece that moves any number of squares horizontally or vertically. Worth 5 points. Participates in castling. Notation letter: R.

Rook lift

Moving a rook up the file (often to the third rank) and then sliding it sideways to join an attack — repurposing a back-rank rook for active duty.

Sacrifice

Voluntarily giving up material in exchange for positional, tactical, or attacking compensation.

Scholar's Mate

A 4-move checkmate pattern using the queen and bishop to attack f7 (or f2). Famous beginner trap. See our Scholar's Mate page.

Semi-open file

Same as half-open file — a file with no friendly pawns but with enemy pawns.

Skewer

Like a pin in reverse — a more valuable piece is attacked in front, and when it moves, a less valuable piece behind is captured.

Smothered mate

Checkmate delivered by a knight when the enemy king is surrounded by its own pieces and has no escape squares. See our Smothered Mate page.

Stalemate

The player to move has no legal moves but is NOT in check. Results in a draw — a common save for the losing side. See our stalemate vs checkmate guide.

Strategy

Long-term planning in chess, as opposed to short-term tactical calculation. See our strategy guide.

Tactic

A short forcing sequence (usually 2-5 moves) that wins material or delivers mate. Examples include forks, pins, and skewers. See tactics page.

Tempo

A single unit of "time" in chess — one move. To "lose a tempo" is to waste a move. To "gain a tempo" is to force the opponent to use a move defensively.

Threefold repetition

A rule allowing either player to claim a draw if the exact same position occurs three times in a game with the same player to move.

Time control

The amount of time each player has to make their moves. Standard categories: bullet, blitz, rapid, classical.

Touch-move rule

A tournament rule requiring that if you touch a piece, you must move it (if a legal move exists). Touching an enemy piece means you must capture it if possible.

Transposition

Reaching the same position through a different move order. Common in openings where various sequences arrive at the same setup.

Trap

A clever move that looks tempting to the opponent but leads to a worse position or loss of material if accepted.

Triangulation

A king maneuver in endgames where the king moves in a triangle pattern to lose a tempo and force the opponent into zugzwang.

Undefended piece

A piece that is not protected by any friendly piece. Vulnerable to tactical attacks. "Loose pieces drop off" — Nunn's law.

Under-promotion

Promoting a pawn to anything other than a queen (rook, bishop, or knight). Rare but sometimes necessary to avoid stalemate or to deliver a fork via knight promotion.

Variation

A specific sequence of moves within a broader opening, line, or game analysis. Openings have multiple named variations.

Weak square

A square that cannot be defended by a friendly pawn. Often becomes an outpost for the opponent.

World Chess Champion

The official title of the world's best chess player, currently determined by a championship match cycle organized by FIDE.

X-ray attack

An attack that operates "through" an enemy piece — if the front piece moves, the attacker reaches a more valuable piece behind it. A type of skewer or pin.

Zugzwang

German for "compulsion to move." A position where any move worsens the player's position, but they must move anyway (since passing isn't legal in chess). Common in endgames.

Zwischenzug

German for "in-between move." Instead of making the expected move (usually a recapture), the player inserts a more important move first (such as a check or threat). Catches even strong players off guard.