The Essential Chess Glossary – Terms, Jargon, and Definitions

A quick reference for all the terms, jargon, and concepts you'll encounter in the world of chess. Click a letter or scroll down to find a term.

A

Absolute Pin: A powerful tactical situation where a piece shields the King from an attack. The pinned piece is legally forbidden from moving because doing so would expose the King to check. Unlike a relative pin, an absolute pin causes total paralysis of the defending piece. (See also: Pin)
Adjudication: The process of a chess arbiter determining the result of an unfinished game based on the position and a player's analysis.
Adjournment: The temporary suspension of a game to be continued later. Rare in modern play due to computer analysis.
Alekhine's Gun: A powerful triple battery where a Queen lines up behind two Rooks on the same file, creating massive pressure.
See Alekhine’s famous “AAA Battery” vs Nimzowitsch »
Algebraic Notation: The standard method for recording chess moves (e.g., e4, Nf3) used in all modern competitions.
Anastasia's Mate: A checkmate pattern executed by a Knight and Rook (or Queen) along the edge of the board. The Knight (usually on e7 or e2) traps the enemy King against the side by controlling two escape squares (g8/g6), while a Rook delivers the final mate on the open h-file. It famously involves a Queen sacrifice to open that file.
Annotation: Commentary, notes, and analysis added to a recording of a game, often using symbols like '!' and '?'.
Arbiter: The referee of a chess tournament responsible for enforcing rules, settling disputes, and ensuring fair play.
Armageddon: A tie-break game where White has more time (e.g., 5 mins) but must win; Black has less time (e.g., 4 mins) but wins if the game is drawn.
Arabian Mate: A classic checkmate pattern delivered by a Rook and Knight working in unison to trap the King in a corner. The Rook delivers the mate (usually on h7, h2, a7, or a2) while the Knight protects the Rook and cuts off the King's diagonal escape square. It is one of the oldest known checkmate patterns.
Artificial Castling: Manually moving the King and Rook over several turns to achieve a castled position when normal castling is illegal.
Attack: An aggressive action attempting to capture a piece, checkmate the King, or create weaknesses in the opponent's camp.
Attraction: A specific tactical motif where you force or lure an opponent's piece—most often the King—onto a vulnerable square to deliver checkmate or a decisive attack. It often involves a sacrifice to "attract" the King out of safety. (See also: Decoy)

B

Back Rank: The first rank (for White) or eighth rank (for Black). A weak back rank can lead to a "Corridor Mate" if the King has no escape square (Luft).
Back-Rank Mate: A checkmate delivered by a Rook or Queen on the 8th rank because the King is trapped by its own pawns. Also known as the "Corridor Mate."
Backward Pawn: A pawn that has fallen behind its neighbors and cannot be supported by other pawns. It is a static structural weakness.
Bad Bishop: A bishop restricted by its own pawns (on the same color squares), reducing its mobility.
Battery: A tactical formation where two or more pieces (e.g., Queen & Bishop, two Rooks) line up on the same rank, file, or diagonal to multiply their attacking power.
Bishop: A minor piece that moves diagonally. Each player starts with two: a light-squared bishop and a dark-squared bishop.
Bishop Pair: Possessing both bishops in an open position is often a statistical advantage over a Knight and Bishop or two Knights.
Black: The designation for the player who moves second in the game. The black pieces are dark-colored.
Blindfold Chess: Playing chess without looking at the board, relying entirely on memory and visualization skills.
Blind Swine Mate: A checkmate pattern where two rooks invade the 7th rank (or 2nd rank for Black), trapping the enemy king with coordinated rook checks. Also informally known as “pigs on the seventh.”
Blitz: Fast chess! Typically 3 to 5 minutes per player. It requires intuition and rapid pattern recognition.
Blockade: Placing a piece (ideally a Knight) directly in front of an enemy passed pawn to physically stop it from advancing.
Blunder: A severe mistake that loses material or the game immediately. Annotated as '??'.
Brilliancy: A game containing a beautiful, original, and correct strategic concept or sacrifice.

C

Candidate Master (CM): A FIDE title ranking below FIDE Master, usually requiring a 2200 rating.
Candidate Move: A shortlist of moves you consciously evaluate before making a decision. The first step of structured calculation.
Castling: The only move where two pieces move at once (King and Rook) to get the King to safety and activate the Rook.
Center: The critical squares e4, d4, e5, and d5. Controlling the center is the primary goal of the opening.
Centralization: Bringing pieces towards the center where they control the most squares and can easily move to either flank.
Check: The king is under immediate attack and must be protected or moved out of check on the next move.
Checkmate: The end of the game: the King is in check and has no legal move to escape.
Clearance Sacrifice: A tactical motif where a piece moves (often sacrificing itself) to vacate a key square or open a line for a stronger piece to attack.
Closed Game: A position with locked pawn chains where lines are blocked. Requires maneuvering and favors Knights over Bishops.
Combination: A forced sequence of moves, often involving a sacrifice, to achieve a specific goal (e.g., Checkmate). See Morphy's Opera Game.
Compensation: Strategic advantages (like time, space, or attack) gained in return for sacrificing material (like a pawn).
Connected Pawns: Pawns on adjacent files that can protect each other. A significant strength in endgames.
Correspondence Chess: Games played over days or weeks per move, historically via mail but now via server. Allows for deep research.

D

Dark Square Complex: A situation where a player is weak on dark squares (due to pawn moves or missing a bishop), allowing the opponent to dominate them.
Decoy: A tactical motif where a move forces or lures an opponent’s piece onto a specific square, making it vulnerable to a follow-up such as mate, material loss, or a decisive gain of tempo. Also known as a decoy sacrifice.
Deflection: A tactical idea where a key defending piece is forced away from an important square or duty. Once deflected, the opponent’s position collapses, often leading to mate or heavy material loss.
See the famous 28…Bg1!! deflection (Lone Pine 1979) »
Desperado: A piece destined to be lost that sacrifices itself for the maximum possible damage before it leaves the board.
Development: Moving pieces from the back rank to active squares. "Develop your pieces!" is the golden rule of the opening.
Discovered Attack: The revealed piece delivers an attack.
Discovered Check: A powerful variant of the discovered attack where the revealed piece delivers a check to the opponent's King.
Double Attack: A simultaneous attack on two targets. While often synonymous with a Fork, a double attack can also combine different types of threats, such as threatening checkmate and capturing a piece at the same time.
Double Check: A check delivered by two pieces at the same time — usually when a move creates a Discovered Check and the moving piece also gives check. In a true double check, the defender’s only response is to move the king (you can’t block or capture your way out of both checks).
Doubled Pawns: Two pawns of the same color on the same vertical file. Usually a structural weakness, but can control key squares.
Draw: A tied game. Can happen via Agreement, Stalemate, Repetition, 50-Move Rule, or Insufficient Material.

E

Elo Rating: The mathematical system used to calculate the relative skill level of chess players. Named after Arpad Elo.
Endgame: The final phase of the game where few pieces remain. King activity and Pawn promotion become the main goals.
En Passant: A special pawn capture rule: "In passing." If a pawn moves two squares and passes an enemy pawn, it can be captured as if it moved only one square.
En Prise: French for "in a position to be taken." A piece left hanging or unprotected.
Exchange: Trading pieces. "Winning the Exchange" specifically refers to winning a Rook for a Minor Piece (Knight/Bishop).
Exchange Sacrifice: Voluntarily sacrificing a Rook for a Minor Piece (Knight/Bishop) to gain a strategic or positional advantage.
Exchange Variation: An opening variation where an early exchange of pawns or pieces occurs to clarify the position.
Expert: A title used to denote a player with a rating below master level (usually 2000-2199 USCF/FIDE).

F

Fianchetto: Developing a Bishop to b2 or g2 (after moving the b/g pawn) to control the long diagonal.
FIDE: The International Chess Federation (Fédération Internationale des Échecs). The governing body of global chess.
FIDE Master (FM): A chess title ranking below International Master but above Candidate Master, usually requiring a 2300 rating.
Fifty-Move Rule: A draw can be claimed if 50 moves pass without a pawn move or a capture.
File: A vertical column on the chessboard (labeled a-h).
Flag: To run out of time on the clock. "I flagged him" means I won on time. Refers to the physical flag on old analog clocks.
Fool's Mate: The fastest possible checkmate (2 moves), occurring if White plays 1. f3 and 2. g4 against Black's ...e5 and ...Qh4#.
Forcing Move: A move that severely limits the opponent's available responses, often dictating the flow of the game. The hierarchy of forcing moves, in order of power, is: Checks, Captures, and Threats. Calculating these first is the key to tactical precision.
Forced Move: A move that a player must make because all other moves lead to immediate loss or are illegal (e.g., getting out of check).
Fork: A tactic where one piece attacks two or more enemy pieces simultaneously. Knights are famous for forking.
Fortress: A defensive setup in the endgame that the opponent cannot break through, salvaging a draw despite being down material.

G

Gambit: An opening where material (usually a pawn) is sacrificed for rapid development or attack (e.g., King's Gambit, Evans Gambit).
Good Bishop: A bishop that is not blocked by its own pawns and is free to control active diagonals.
Grandmaster (GM): The highest title in chess, awarded by FIDE for achieving a 2500 rating and three "norms."
Greek Gift: The classic sacrifice Bxh7+, exposing the enemy King to a mating attack. Requires a Knight jump to g5 and Queen to h5.

H

Hanging: Slang for leaving a piece unprotected and en prise (ready to be captured for free).
Hedgehog: A solid pawn structure (pawns on e6, d6, b6, a6) that is hard to break and stores up potential energy.
Hole: A square that can no longer be controlled by pawns. A hole is a permanent structural weakness and often becomes the basis for an outpost.
Hypermodernism: A school of chess theory that prefers controlling the center from a distance with pieces (e.g., Fianchetto) rather than occupying it immediately with pawns.

I

Imbalance: Any difference between the White and Black position (e.g., Bishop vs Knight, Space vs Structure). Imbalances dictate the plan.
Increment: Time added to the clock after every move (e.g., "3 minutes + 2 seconds increment").
Initiative: The momentum of the game. The player with the initiative is making threats that force the opponent to react.
Insufficient Material: A draw declared when neither side has enough pieces to force a mate (e.g., King vs King, or King+Knight vs King).
Interference: A tactical theme where a piece is sacrificed or moved to block the line of defense between two enemy pieces.
Intermezzo: See Zwischenzug.
International Master (IM): A strong FIDE title below Grandmaster, requiring a 2400 rating and norms.
Isolated Pawn (IQP): A pawn that has no friendly pawns on the adjacent files. It can be a dynamic strength in the middlegame but a static weakness in the endgame.

J

J'adoube: French for "I adjust." You must say this before touching a piece if you only intend to center it, to avoid the "Touch-Move" rule.

K

Key Square: A square in a pawn endgame that guarantees a win if the King occupies it (often related to Opposition).
Kibitzer: A spectator who offers (often unwanted) advice. In online chess, "Kibitzing" refers to chat analysis by spectators.
King: The most important piece. The game is lost if the King is checkmated.
King Hunt: A tactical sequence where the opponent's King is forced out of its defensive shell and subjected to a series of checks, often leading it across the board into a checkmate net.
King Safety: The concept of keeping the King secure, usually by castling early and keeping pawn shields intact.
Kingside: The half of the board where the King starts (files e, f, g, h).
Knight: The piece that moves in an "L" shape and can jump over other pieces. Excellent in closed positions and for forking.

L

Liquidation: Trading off pieces to clarify the position, often to transition into a won Pawn Endgame.
Long Diagonal: The two longest diagonals on the board: a1-h8 and h1-a8.
Loose Piece: A piece that is undefended (hanging) or insufficiently defended. Loose pieces are the most common targets for tactical combinations like forks and double attacks. The famous maxim states: "Loose pieces drop off" (LPDO).
Lucena Position: The "Building a Bridge" technique. Essential knowledge for winning Rook & Pawn endgames.
Luft: German for "Air." Moving a pawn in front of the castled King to create an escape square and prevent back-rank mate.

M

Major Piece: Rooks and Queens. Also called "Heavy Pieces."
Maróczy Bind: A pawn structure (pawns on c4 and e4) that clamps down on Black's d5 break, cramping Black's position.
Mate: Short for Checkmate.
Mating Net: A position where pieces cooperate to cut off all escape squares for the King, making checkmate inevitable.
Material: The total value of pieces on the board. (Pawn=1, Knight/Bishop=3, Rook=5, Queen=9).
Middlegame: The combat phase after the opening. Plans are formed, tactics occur, and pieces are maneuvered.
Miniature: A decisive game lasting fewer than 20-25 moves.
Minor Piece: Bishops and Knights (value approx 3 points).
Minority Attack: Advancing fewer pawns against a pawn majority (e.g., 2 vs 3) to create a weakness (often in the Carlsbad structure).
Mysterious Rook Move: A move by Nimzowitsch where a Rook moves to a closed file to discourage the opponent from opening it later.

N

Norm: A high-performance result in a tournament that counts toward the IM or GM title.
Notation: The system of writing down moves (e.g., 1. e4 e5). See How to Keep Score.
Novelty: A new move played in a known opening position (Theory) that hasn't been seen in master play before.

O

Open File: A file with no pawns. Rooks belong on open files!
Opening: The first phase of the game (approx moves 1-10). See our Repertoire Guide.
Opposite-Colored Bishops: A situation where each player has one bishop on different colors (e.g., Light vs Dark). It favors the attacker in middlegames but favors a draw in endgames.
Opposition: A crucial endgame concept where Kings face each other. The player who *doesn't* have to move "has the opposition" and can force the enemy King back.
Outpost: A strong square (often in enemy territory) where a piece—especially a knight—can sit securely because it cannot be driven away by pawns.
Outside Passed Pawn: A passed pawn on the wing (a or h file) that distracts the enemy King, often allowing the main army to clean up the center.
Overloading: A tactical theme where a single defending piece has too many responsibilities. By creating an extra threat, you force the defender to fail at one of its jobs — often losing material or getting checkmated.
See Keres’ textbook overload mate (Kemeri 1937) »
Overprotection: A strategic concept (popularized by Nimzowitsch) of defending a strong point more times than strictly necessary to free up pieces for other duties.

P

Passed Pawn: A pawn with no enemy pawns ahead of it or on adjacent files. It is a candidate to promote to a Queen.
Patzer: German slang for a weak or bungling chess player ("fish").
Pawn: The foot soldier of chess. "Pawns are the soul of chess" (Philidor).
Pawn Chain: A diagonal line of pawns protecting each other. The base of the chain is the weak point.
Pawn Island: A group of connected pawns separated from others. Having fewer pawn islands is generally better for the endgame.
Pawn Storm: Advancing multiple pawns on one wing to attack the enemy King (e.g., in the Sicilian Defense or King's Indian).
Perpetual Check: Forcing a draw by checking the enemy King endlessly, when there is no checkmate but the King cannot escape the checks.
Philidor Position: The "Gold Standard" defensive technique in Rook endings to secure a draw against a pawn.
Piece: Technically refers to non-pawns (Knights, Bishops, Rooks, Queens, King). Informally, any man on the board.
Pin: A tactical motif where a piece cannot (or should not) move because doing so would expose a more valuable piece behind it. An absolute pin involves the king and cannot be broken; a relative pin involv
Poisoned Pawn: A pawn (often on b2/b7) that is free to take but taking it leads to dangerous complications or traps.
Positional Play: Improving your position gradually through structure, space, and piece activity, rather than immediate tactics.
Premove: An online chess feature where you input your move during your opponent's turn. It takes 0.1 seconds off your clock.
Promotion: When a pawn reaches the 8th rank, it transforms into a Queen, Rook, Bishop, or Knight.
Prophylaxis: The art of preventing your opponent's plans before they happen. "Thinking about what they want to do."

Q

Queen: The most powerful piece. It combines the movement of Rook and Bishop.
Queening: Promoting a pawn to a Queen.
Queenside: The half of the board where the Queen starts (files a, b, c, d).
Quiet Move: A move that is not a check or capture, but creates an inescapable threat (often stronger than a check).

R

Rank: A horizontal row on the chessboard (labeled 1-8).
Rapid Chess: A time control longer than Blitz but shorter than Classical (e.g., 15 to 30 minutes). The "sweet spot" for improvement.
Rating: A numerical value indicating skill. Beginners often start around 400-800; Masters are 2200+.
Relative Pin: A tactical situation where a piece shields a valuable piece (such as a Queen or Rook) other than the King. Unlike an Absolute Pin, the pinned piece is legally allowed to move, but doing so usually results in the loss of the more valuable piece behind it.
Removing the Defender: What is saids on the tin! - An important tactical idea for winning chess.
Refutation: Demonstrating that a move, opening, or combination is incorrect.
Resignation: Conceding defeat before being checkmated. Considered polite if the position is hopelessly lost.
Romantic Chess: The style of chess from the 19th century (Anderssen, Morphy) characterized by wild gambits, sacrifices, and attacking play.
Rook: A major piece that moves in straight lines. Rooks are powerful in the endgame and on open files.
Rook Lift: Moving a Rook forward (e.g., to the 3rd rank) to transfer it to an attack on the other side of the board.

S

Sacrifice: Voluntarily giving up material (Pawn, Exchange, or Piece) to gain a tactical or strategic win.
Scholar’s Mate: A beginner checkmate pattern where the queen and bishop quickly target the f7 (or f2) square, leading to mate in four moves if the defender fails to respond correctly.
Second: An assistant to a top player (like in the World Championship) who helps with opening preparation.
Semi-Open File: A file where you have no pawns, but your opponent does. It is a target for Rooks to attack the enemy pawn.
Sharp: A position full of tactical possibilities where a single mistake can lose the game instantly. The opposite of "Quiet."
Simul: Simultaneous Exhibition. An event where one strong player (often a master) plays multiple games against different opponents at the same time.
Skewer: A "Reverse Pin." Attacking a valuable piece which must move, exposing a less valuable piece behind it to capture.
Smothered Mate: A spectacular mate by a Knight where the King is surrounded ("smothered") by its own pieces and cannot move.
Sofia Rules: Tournament rules forbidding draw offers before a certain move number (usually move 30) to encourage fighting chess.
Space: The amount of territory (squares) controlled by a player. A space advantage allows for greater mobility.
Spite Check: A useless check given by a losing player just to prolong the game for one more move.
Stalemate: A draw where the player to move has no legal moves, but their king is not in check.
Stem Game: The original game that introduced a specific opening variation.
Strategy: Long-term planning (pawn structure, bad bishops) as opposed to short-term tactics.
Swiss System: The most common tournament format where winners play winners, and losers play losers, without eliminating anyone.
Swindle: A trick or trap used by a player in a losing position to turn the tables or achieve a draw.
Symmetry: When Black copies White's moves. Usually dangerous for Black as White moves first and strikes first.

T

Tabiya: A standard position in an opening that is reached frequently, from which the real game and deviation from theory begins.
Tactics: Short-term sequences of moves (forks, pins, skewers) that result in immediate material gain or mate.
Tempo: Time in terms of moves. "Gaining a tempo" means developing a piece while forcing the opponent to waste a move defending.
Theoretical Draw: An endgame known to be a draw with perfect play (e.g., King+Bishop vs King), regardless of how much time is left.
Threefold Repetition: A draw occurs if the exact same position (same player to move, same legal moves) appears on the board three times.
Time Control: The rules regarding time (e.g., 90 minutes for 40 moves). See our guide on Blitz vs Rapid vs Bullet.
Time Trouble: Having very little time left on the clock (e.g., under 1 minute), which often leads to blunders.
Touch-Move Rule: If you touch a piece in an OTB tournament, you MUST move it (if legal). If you touch an enemy piece, you must capture it.
Transposition: Reaching a standard opening position via a different move order (e.g., reaching a French Defense from a Queen's Pawn opening).
Trap: A move that encourages the opponent to make a natural-looking response that actually loses material or leads to mate.
Trapping: A tactic where a piece (often a Queen or Bishop) is surrounded by enemy pieces or the board edge and has no legal escape squares.
Triangulation: A King maneuver in the endgame used to lose a tempo and pass the move to the opponent while maintaining the same position (forcing Zugzwang).

U

Undermining: Tactically: Capturing or driving away a defending piece ("Removing the Guard"). Strategically: Attacking the base of a pawn chain to weaken the entire structure.
Underpromotion: The promotion of a pawn to a piece other than a Queen (usually a Knight or Rook). This is typically done to deliver a specific check or to avoid stalemate.

This glossary covers the most important terms. For in-depth guides on openings, strategies, and famous games, please explore the rest of our Chess Strategy sections.

The Essential Chess Glossary – Terms, Jargon, and Definitions

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