Chess Glossary: Every Term Explained
Chess has its own language, and it can feel impenetrable when you're starting out. This glossary explains every common term in plain English, grouped alphabetically, so you can look up anything you hear at the board or read online.
A
| Term | Meaning |
|---|
| Algebraic notation | The standard system for recording chess moves, using letters a–h for files and numbers 1–8 for ranks (e.g. Nf3, e4). Every square on the board has a unique name. |
B
| Term | Meaning |
|---|
| Back rank | The row closest to each player (rank 1 for White, rank 8 for Black). A "back-rank mate" happens when a rook or queen delivers checkmate along this row because the king has no escape square. |
| Bishop pair | Owning both of your bishops while your opponent has traded one or both of theirs away. Generally a small advantage, since two bishops together cover every square on the board. |
| Blitz | A fast time control, typically 3–5 minutes per player for the whole game, leaving little time for deep calculation. |
| Blunder | A serious mistake that loses material or the game outright — usually marked with "??" in annotated games. |
| Book move | A move that follows established opening theory, i.e. it's been analysed and played many times before and is recorded in opening references ("the book"). |
C
| Term | Meaning |
|---|
| Candidate move | A move worth seriously considering during calculation, before you decide which one to actually play. |
| Castling | A special move where the king moves two squares toward a rook and the rook jumps to the square beside the king, done to get the king to safety and connect the rooks. See How to Play Chess for the full rules. |
| Centre (center) | The four central squares (d4, d5, e4, e5), and often the surrounding region. Controlling the centre gives pieces more mobility and is a core opening principle. |
| Check | A position where the king is under direct attack and must be addressed immediately — by moving, blocking, or capturing the attacker. |
| Checkmate | A check that cannot be escaped by any legal move. The game ends immediately and the side delivering mate wins. |
| Classical (time control) | A long time control, often 90 minutes or more per player, used in serious over-the-board tournaments and allowing deep calculation. |
D
| Term | Meaning |
|---|
| Development | Bringing your pieces (especially knights and bishops) off their starting squares and into active, useful positions early in the game. |
| Discovered attack | An attack revealed when one piece moves out of the way of another piece behind it. See Chess Tactics for worked examples. |
| Draw | A game that ends without a winner — by agreement, stalemate, threefold repetition, insufficient material, or the 50-move rule. |
E
| Term | Meaning |
|---|
| En passant | A special pawn capture: if an enemy pawn moves two squares forward and lands beside your pawn, you may capture it as if it had only moved one square — but only on the very next move. |
| Endgame | The final phase of the game, after most pieces have been traded off, where kings become active and pawn promotion is often decisive. |
| Exchange | Trading pieces of roughly equal value. "Winning the exchange" specifically means winning a rook for a minor piece (bishop or knight). |
F
| Term | Meaning |
|---|
| Fianchetto | Developing a bishop to the long diagonal by moving it to b2/g2 (White) or b7/g7 (Black), after fianchettoing the adjacent knight-file pawn. |
| FIDE | The Fédération Internationale des Échecs, chess's world governing body, which sanctions official ratings and world championship events. |
| Fork | A single piece attacking two or more enemy targets at once, so the opponent can only save one. Full explanation on the Chess Tactics page. |
G
| Term | Meaning |
|---|
| Gambit | An opening in which a player deliberately sacrifices a pawn (or occasionally more) for faster development or attacking chances. See Chess Openings. |
| Grandmaster (GM) | The highest title FIDE awards, earned through strong tournament performances ("norms") plus a rating typically above 2500. |
I
| Term | Meaning |
|---|
| Insufficient material | A draw that occurs when neither side has enough material left to force checkmate, such as king and bishop versus lone king. |
| Isolated pawn | A pawn with no friendly pawns on the adjacent files, meaning it can never be defended by another pawn — a long-term structural weakness. |
J
| Term | Meaning |
|---|
| J'adoube | French for "I adjust" — said before touching a piece just to straighten it on its square, without intending to move it, which avoids triggering the touch-move rule. |
K
| Term | Meaning |
|---|
| King safety | How exposed or protected a king is to attack. A major factor in evaluating a position, independent of material. |
| Kingside | The half of the board containing the e, f, g and h files — the side the king starts on. |
L
| Term | Meaning |
|---|
| Luft | German for "air" — a small escape square made for the king (usually by pushing a pawn one square) so it can't be trapped on the back rank. |
M
| Term | Meaning |
|---|
| Major piece | A queen or rook — pieces powerful enough to deliver checkmate without help from another piece. |
| Mate | Short for checkmate. |
| Middlegame | The phase after the opening and before the endgame, where most tactical and strategic battles play out. |
| Minor piece | A bishop or knight — weaker than rooks and queens, but essential for both attack and defence. |
O
| Term | Meaning |
|---|
| Opening | The first phase of the game, typically the first 10–15 moves, focused on development, king safety and central control. See Chess Openings. |
| Opposition | An endgame concept where two kings face each other with one square between them; whoever is not to move has "the opposition" and usually the advantage. |
| Outpost | A square (often for a knight) that's protected by a pawn and can't be challenged by an enemy pawn, making it a strong permanent base for a piece. |
P
| Term | Meaning |
|---|
| Passed pawn | A pawn with no enemy pawns able to stop it from promoting — none on its own file or the two adjacent files ahead of it. |
| Perpetual check | A sequence of checks that repeats indefinitely, giving neither side a way to avoid a draw — often used to save an otherwise losing position. |
| Pin | A piece that can't (or shouldn't) move because a more valuable piece stands behind it on the same line. Detailed on the Chess Tactics page. |
| Promotion | When a pawn reaches the far rank, it must be exchanged for a queen, rook, bishop, or knight of the same colour. |
| Prophylaxis | A strategic move made to prevent an opponent's plan before it happens, rather than to create your own threat. |
Q
| Term | Meaning |
|---|
| Queenside | The half of the board containing the a, b, c and d files — the side the queen starts on. |
R
| Term | Meaning |
|---|
| Rapid | A time control between blitz and classical, commonly 10–25 minutes per player. |
| Resign | To voluntarily concede the game as lost, rather than play on to checkmate. |
S
| Term | Meaning |
|---|
| Sacrifice | Deliberately giving up material — a pawn, piece, or more — in exchange for a stronger attack, better position, or forced sequence leading to an advantage. |
| Sicilian | The Sicilian Defence (1.e4 c5), the most popular and sharpest response to 1.e4 at every level. See Chess Openings. |
| Skewer | The reverse of a pin: a valuable piece is attacked first, and when it moves, a less valuable piece behind it is captured. See Chess Tactics. |
| Stalemate | A draw that occurs when the player to move has no legal move and is not in check — a common way to save a lost position. |
T
| Term | Meaning |
|---|
| Tempo | A single "turn" of time. Gaining a tempo means making progress while also forcing your opponent to react, effectively getting a free move. |
| Theory | The accumulated body of analysed opening lines and known best moves, built up over decades of play and engine analysis. |
| Threefold repetition | A draw claimable when the exact same position occurs three times, with the same player to move each time. |
| Touch-move | The rule that if you touch a piece with intent to move it, you must move it (if a legal move exists); touching an enemy piece means you must capture it if possible. |
U
| Term | Meaning |
|---|
| Underpromotion | Promoting a pawn to a rook, bishop, or knight instead of a queen — rare, but occasionally the only move that avoids stalemate or wins by force. |
Z
| Term | Meaning |
|---|
| Zugzwang | A situation where a player would prefer to pass, because any legal move they make worsens their position — but passing isn't allowed in chess, so they must move anyway. |
| Zwischenzug | German for "in-between move" — an unexpected intermediate move inserted into an expected sequence, usually a check or strong threat, before completing the original exchange. |
Frequently asked questions
What does "J'adoube" mean?
It's French for "I adjust", said before touching a piece just to straighten it on its square without intending to move it — this avoids triggering the touch-move rule.
What's the difference between a major and minor piece?
Major pieces (queen and rook) are powerful enough to deliver checkmate on their own; minor pieces (bishop and knight) generally need support from other pieces to do so.
What is zugzwang?
A situation where any legal move a player makes worsens their position, but since passing isn't allowed in chess, they're forced to make it anyway. It's especially common in king and pawn endgames.
What's the difference between a pin and a skewer?
In a pin, the less valuable piece is attacked first and can't move without exposing a more valuable piece behind it. In a skewer, the more valuable piece is attacked first and must move, exposing the less valuable piece behind it to capture.