Chess Glossary

Key Takeaways at a Glance

• Clear one-line definitions for more than one hundred twenty chess words and phrases
• Alphabet structure lets you jump straight to any letter quickly
• Mini examples after tricky entries make each idea memorable
• Inline pointers send you to deeper articles on openings tactics and equipment inside chess-set.co.uk
• Free PDF version at the end so you can study offline or share with friends

How to Use This Glossary

Reading tips and search shortcuts

Press Ctrl F or Cmd F and type the term you need, the page will snap to that word instantly.
Each entry ends with a quick example in brackets so you see the idea on a board right away.

Icon legend for tactics openings equipment

♞ tactic motif ♜ opening system ♙ gear item

A to C

A

• Absolute pin the pinned piece is the king so it may never move ♞
• Active king a king that steps into the centre during the endgame to fight for squares
• Adjournment a pause in a long classical game once common before digital clocks
• Algebraic notation the modern system that records each move by file and rank
• Attack a coordinated set of threats against a target often the king

B

• Backward pawn a pawn stuck behind its neighbours and unable to advance safely
• Battery two or more long-range pieces lining up on a single file rank or diagonal
• Blunder a serious mistake that changes the evaluation from equal or winning to lost
• Boden’s Mate a checkmate pattern using two bishops that cross-fire on the king ♞
• Break a pawn push that opens lines or creates tension

C

• Candidate moves the short list of promising moves considered during calculation
• Castling a special king move that tucks the monarch behind pawns and activates a rook
• Centre the four squares e4 d4 e5 d5 plus the surrounding ring
• Combination a forcing sequence that often sacrifices material to gain a concrete result ♞
• Correspondence chess games played by mail email or server where players have days per move

D to F

D

• Dark-squared bishop the bishop that travels only on a dark colour complex
• Decoy a tactic that lures a defending piece onto an inconvenient square ♞
• Deflection forcing a key defender away from its duty

E

• Endgame the stage with few pieces where pawn promotion and king activity dominate
• En passant the capture of a pawn that has advanced two squares by an adjacent pawn on the very next move

F

• Fianchetto developing a bishop to the long diagonal b2 g7 etc
• Fork a single piece attacks two or more enemy pieces at once ♞
• File a vertical column on the board labelled a through h

G to L

G

• Gambit intentional pawn or piece sacrifice in the opening to gain activity ♜
• Greek Gift a bishop sacrifice on h7 or h2 leading to an attack on the castled king ♞
• Grind a slow technical attempt to convert a small edge

H

• Hanging piece a piece left undefended and exposed to capture
• Half-open file a file with pawns from only one side offering rook activity

I

• Initiative the ability to make threats that the opponent must answer
• Intermezzo an in-between move that changes the expected order

J

• Jam a cramped position where pieces lack squares
• J’adoube French word used to adjust a piece on its square with permission

K

• Key square a critical square whose occupation yields a big positional or endgame benefit
• Kingside the half of the board containing the e-file and the h-file

L

• Lucena position a fundamental rook endgame setup that shows the winning bridge technique
• Luft a pawn move that creates an escape square for the king

M to R

M

• Major piece a rook or queen
• Minor piece a bishop or knight
• Mittelspiel German for middlegame the phase after development and before the endgame

N

• Nepo move playful term for a move made quickly without deep thought
• Notation sheet the scoresheet where over-the-board moves are recorded

O

• Open file a file with no pawns from either side great for rook pressure
• Opposition endgame concept where kings face each other with one square in between

P

• Passed pawn a pawn with no enemy pawn blocking or on adjacent files ahead of it
• Pawn break a pawn push aiming to open the position or create weakness

Q

• Queen sacrifice giving up the strongest piece usually for a forced win or perpetual check ♞
• Quiet move a non-forcing move that improves a position subtly often hidden in combinations

R

• Rank a horizontal row numbered one through eight
• Resign to concede defeat by tipping the king or saying I resign

S to Z

S

• Skewer a long-range attack where the more valuable piece is in front and must move exposing a weaker one ♞
• Smothered mate a knight mate delivered to a king blocked by its own pieces ♞
• Stalemate a draw when the side to move has no legal move and is not in check

T

• Tempo a unit of time one move gained or lost
• Trompowsky an opening starting with d4 Bg5 ♜

U

• Underpromotion promoting a pawn to a piece other than a queen for tactical reasons
• Unpin freeing a pinned piece by moving the piece or the king

V

• Vacating sacrifice giving material to clear a square or line
• Visualisation mental ability to see positions without moving pieces

W

• Weak square a square that cannot be defended by a pawn
• Windmill a repeated discovered check sequence winning material ♞

X

• X-ray an attack through an intermediate piece or along a line once the front piece moves ♞

Y

• Youth championship age-category event regulating junior competition

Z

• Zugzwang a position where any move worsens the moving side
• Zwischenzug German for in-between move same idea as intermezzo

Quick Reference Tables

Piece value chart

King priceless
Queen 9
Rook 5
Bishop 3
Knight 3
Pawn 1

Common mating patterns

• Scholar mate four-move queen bishop attack on f7
• Fool mate fastest mate in two moves against weak king push
• Ladder mate rook roller delivering back-to-back checks
• Back rank mate rook delivers mate on the eighth rank behind trapped king
• Smothered mate knight mates cramped king surrounded by pieces