Endgame    The final phase of the game when there are few pieces left on the board. The endgame generally starts after queens have been exchanged or when the immediate goal is to promote a pawn.

En passant    French "in passing." It occurs when a pawn moves two squares from its starting position, and passes an enemy pawn that has advanced to its fifth rank. The advanced pawn on the fifth rank may choose to capture the pawn as if the pawn had only moved forward one square. This capture must be made immediately after the two square advance, or else the right to capture "en passant" is lost. In some chess notations an en passant capture is labelled "e.p."

En prise    French "in take" A piece or pawn that is unprotected and exposed to capture.

Equality    Where neither player has a discernible advantage over the opponent.

Exchange    A trade of pieces. Trading a minor piece for the opponent’s rook is called "winning the exchange". Trading a rook for the opponent’s minor piece is called "losing the exchange". See "Point count".

Exchange sacrifice    Where a player willfully trades a rook for a minor piece in return for compensation of some kind. See "Compensation".

Expansion    Increasing the amount of space directly under your control. To expand, push pawns forward in an attempt to increase the boundaries of your territory.

Fianchetto    Italian "on the flank". The development of a bishop to b2 or g2 (b7 or g7 for Black).

FIDE    Federation Internationale des Echecs, the world governing body for chess. Founded in 1924, it organizes world championship competitions, draws up rules of the game, and awards the international titles to top players.

Fifty move rule    A game can be drawn when fifty moves have been made by each player without a capture or pawn advancement.

File    A row of eight squares from one end of the chessboard to the other. In Algebraic Notation these are labelled a to h, starting from the queenside of the board.

Fixed centre    Where the centre of the board is occupied by multiple pawns and some of them are fixed in place by opposing pawns. In some cases, pawn movement is possible but the advancing pawns will be subject to capture.

Fixed pawn structure    Pawn set-ups where there is little or no possible mobility. Since there will be little pawn play, strategies are easier to determine.

Flank    The files that do not belong to the centre, that is the a, b and c files on the queenside, and the f, g and h files on the kingside. Certain openings that focus on flank development are called "flank openings." Typical first moves for these openings are 1.c4; 1.b3; 1.Nf3; etc.

Flank attack    Attacking on either the kingside or queenside. Such attacks are much more successful when the centre is closed.

Fluid pawn structure    Structures where future pawn movement is likely. Strategy may be difficult to determine, as a change in the pawn structure necessitates a change in strategy.

Focal point    A weak square near the enemy king. This is targeted by the attacker, and the defender may find it difficult to protect. More than one focal point makes an attack stronger.

Fool’s mate    Checkmate in the manner of 1. f3 e3 2. g4 Qh4*

Force    Your army. All pawns and pieces are units of force.

Forced    A move or series of moves that must be played to avoid loss of the game or catastrophic loss of material.

Forcing move    A move which leads the opponent into a forced move or moves.

Forepost    An advanced square which cannot be attacked by a hostile piece of inferior rank. Foreposts are ideal squares for attacking knights as they have a short range. An absolute forepost is where the position is unassailable. A contingent forepost can only be attacked at the cost of creating a weakness elsewhere.

Fork    A form of double attack where one piece threatens two enemy pieces at the same time. In a triple fork, three enemy pieces are threatened.

Fortress    A defensive blockade to keep out the enemy forces, especially the king.

Forward Pawn    A pawn that is at the very front of a pawn chain. It is the only pawn contained in the chain that does not protect another pawn.

Frontal assault    A direct attack on an enemy pawn that is located on the same half-open file as your heavy pieces.

Gambit    Italian "a trip up". Where the first player voluntarily sacrifices a pawn or piece in the opening for positional or developmental advantage. A counter-gambit is where the second player makes a similar sacrifice for similar aims.

General principles    Basic rules that serve as guidelines for less advanced players. Basic rules don't apply to all situations, and more experienced players learn when to apply them in each specific position.

Ghosts    Threats created in the mind of inexperienced players due to lack of confidence or fear of their opponent.

Good bishop    1. A bishop not hindered by friendly pawns on the same colour squares.
2. A bishop with adequate scope.

Grab    Capture a piece, perhaps making a positional concession in the process.

Grandmaster    The highest title (apart from World Champion) that a chess player can achieve. It is bestowed by FIDE upon players who have achieved certain performance norms. Abbreviation GM. Other titles (in order of importance) are International Master and FIDE Master.

Grandmaster draw    A quick, uninteresting draw.

Half-open file    A file with pawns of only one colour on it. This file is closed to the pawn owner, and open to the other player.

Hanging    A pawn or piece subject to immediate capture. Also "En prise".

Heavy pieces    Rooks and queens, also known as "major pieces" or "heavy artillery."

Hold    To hang on, to allow a successful defense.

Hole    A square that is undefendable by pawns. Such a square serves as an excellent home for enemy pieces, especially the knight.

Illegal move    A move made contrary to the rules of chess.

Imbalance    A noticeable difference between the white and black armies. This may include material advantage, superior pawn structure, space, development, the initiative, or a superior minor piece.

Impossible move    A move which has obvious unfavourable results, and so is to be avoided.

Inactive piece    A piece not directly involved in the flow of the game.

Initiative    The player that is on the attack, or otherwise applying pressure to the opponent on the defensive, is said to "have the initiative."

Innovation    A novel move or idea in an established line of play.

Insufficient material    When neither player has enough pieces to mate their opponent. A draw is declared.

Interference move    A move which obstructs the line of attack of an enemy piece.

International master    The next highest title below Grandmaster. Abbreviation IM.

Interpose    Placement of a piece between an attacking enemy queen, rook or bishop, and the piece being attacked.

Intuition    A ability of an experienced player to decide on a move or plan by feel, rather than by extensive analysis.

Isolated pawn    A pawn with no friendly pawns on the adjacent files. It cannot be protected by pawns, and the square directly in front of it can be a safe haven for enemy pieces as they cannot be threatened by pawns.
J’Adoube    French "I adjust". Expression used prior to a piece being adjusted on its square.

Kingside    The half of the board from which the king starts. The e, f, g and h files.

Knight on the rim    A knight on the edge of the board. Unless it is performing a specific duty, its future is said to be "dim," as it attacks very few squares, none in the centre. It may even become trapped on the edge.

Liquidation    1. A series of exchanges that are done to slow or halt the enemy's attack.
2. To trade off in order to enter a drawn or won endgame.

Locked centre    Similar to a fixed centre except that no pawn movement is possible.

Luft    German "air." Moving a pawn so the king has an escape square to prevent back-rank mates.

Main line    The principal variation used or analysed.

Major piece    A rook or queen.

Manoeuvre    A series of quiet moves designed to redeploy your pieces more favourably.

Master    A player whose Elo rating is 2200 or higher. If the player's rating drops below 2200 the title is revoked.

Mate    See "Checkmate".

Material    Your pieces and pawns (excluding the king). See "Force".

Mating attack    An attack against the enemy king that leads to possible checkmate, or where mate can be averted by the enemy sacrificing material. Either way, a winning advantage is obtained by the attacker.

Mating net    A mating attack that leads to mate with correct play, no matter what the enemy does. A forced mating attack.

Middlegame    The phase of the game between the opening and endgame. The middlegame generally commences after development has been completed by both sides.

Minor piece    A bishop or knight.

Minority attack    An attack on a pawn majority by a pawn minority. This usually occurs on the queenside. The idea is to force a pawn trade that creates a pawn weakness in the enemy pawn structure.

Mobility    How much freedom of movement the pieces have. A piece's value is increased when it has more mobility, as it has more attacking power. See "Scope".

Notation    A system of symbols and coordinates for recording the moves of a game. See "Algebraic notation".

Occupation    1. Placement of a rook or queen on a rank or file, or a bishop or queen on a diagonal, to exert control over it.
2. Placement of a piece safely on a square to exert pressure from it.

Open    1. A type of position (see "Open Game") or file (see "Open File").
2. A type of tournament in which any class of player can participate.

Open file    A file where no pawns are present. Rooks are at their strongest when placed on open files.

Open game    A position where there are few centre pawns, and many open attacking lines. A lead in development is crucial to exploiting an open position.

Opening    The beginning phase of a game, usually the first 10-15 moves. It is characterized by rapid development of forces, control and/or occupation of the centre, and getting the king to safety. The real purpose of the opening is to create an imbalance in the enemy's camp, and development of pieces to exploit this imbalance.

Openings    A specific sequence of moves which have been catalogued over time. Specific openings are often played because players have analysed them thoroughly and believe they are the best way to achieve the initiative. There are over 1000 openings and many, many more variations. Most are named after the player, region or type of moves that are played, such as the Alekhine Defense, King's Gambit and Sicilian Defense.

Opening book    See "Book".

Opening library    See "Book".

Opening repertoire    A set of openings that a player prepares in advance to get to a preferred middlegame position.

Opposite colour bishops    Where each side has only one bishop that travels on squares of a different colour from that of the enemy. This can be effective during an attacking middlegame, as the defending bishop cannot control the squares the attacking bishop travels on. In an endgame, opposite colour bishops generally signal a draw, as the defender can put his king and pawns on the opposite colour of the attacker's bishop.

Opposition    An endgame term meaning the king not forced to move. Where the two kings stand on the same file or diagonal with an odd number of squares between them, the player that doesn't have to move is said to "have the opposition." This is important in king and pawn endings as the player who can secure the opposition can effectively guard certain spaces or drive the opposing king back.

Orientation    The way the board is positioned. The correct way has each player with a white square in their right hand corner.

Outflanking    A manoeuvre in the endgame with kings where one makes forward progress up the board while: 1) not allowing the opponent to gain the opposition, or 2) temporarily giving up the opposition in order to achieve a certain goal.

Outpost    A safe square near or in enemy territory that is protected by friendly pawns or pieces, and subject to effective occupation by one of your pieces.

Outside passed pawn    A passed pawn on the flank which is far from all the other pawns on the board.

Overextended    The position after a failed offensive or advance, in which a player's position is left with various weaknesses and no compensation for them.

Overprotection    Defending a strong point more times than appears necessary. The idea is that the overprotected pawn or square may be causing considerable problems for the opponent, who would be unwise to try to break the strong point, because he would release the latent power of the protecting pieces. See also "Prophylaxis".

Overworked piece    A piece which is required to do too much, defending too many pieces or squares at once. These pieces are open to attack, because moving them leads to a number of weaknesses being exposed.

Passed pawn    A pawn that has advanced past any enemy pawn that could hinder or capture it. Passed pawns are what are needed to promote.

Passive    An inactive move or plan that doesn't fight for the initiative. A passive position has no hope of counterplay or active possibilities. A passive player favours defense rather than attack.

Pawn centre    Pawns based in the centre of the board, primarily on d4, e4, d5 or e5.

Pawn chain    Two or more similarly-coloured pawns linked on a diagonal. The weakest point of such a chain is its base, as that pawn cannot be defended by another pawn.

Pawn contact    Opposing pawns are "in contact" when they are able to capture each other. Capturing resolves the tension in the position; maintaining contact maintains the tension.

Pawn duo    Two pawns of the same colour that are side by side and touching each other.

Pawn island    A group of pawns of the same colour separated from the next pawn by at least one open file. More islands indicates a weaker pawn structure.

Pawn storm    Advancing one or more pawns towards the enemy king with the intent of ripping up his pawn cover. Often used when both players have castled to opposite sides.

Pawn structure    The position of all the pawns.

Petite combination    A combination involving only a few moves and often only one tactical theme.

Perpetual check    Unremitting attack on a king, without checkmate. Under some rules this may result in a draw.