Outline of chess

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https://en.wikipedia.org/wiki/Outline_of_chess

Starting position of a game of chess

 

The following outline is provided as an overview of and topical guide to chess: 

Chess is a two-player board game played on a chessboard (a square-checkered board with 64 squares arranged in an eight-by-eight grid). In a chess game, each player begins with sixteen pieces: one king, one queen, two rooks, two knights, two bishops, and eight pawns. The object of the game is to checkmate the opponent's king, whereby the king is under immediate attack (in "check") and there is no way to remove or defend it from attack, or force the opposing player to forfeit.

Nature of chess

Chess can be described as all of the following:

• Form of entertainment – form of activity that holds the attention and interest of an audience, or gives pleasure and delight.
  • Form of recreation – activity of leisure, leisure being discretionary time.
    • Form of play – voluntary, intrinsically motivated activity normally associated with recreational pleasure and enjoyment.
      • Game – structured playing, usually undertaken for enjoyment and sometimes used as an educational tool. Games are distinct from work, which is usually carried out for remuneration, and from art, which is more often an expression of aesthetic or ideological elements. However, the distinction is not clear-cut, and many games are also considered to be work (such as professional players of spectator sports/games) or art (such as jigsaw puzzles or games involving an artistic layout such as Mahjong, solitaire, or some video games).
        • Board game – game in which counters or pieces are placed, removed, or moved on a premarked surface or "board" according to a set of rules. Games may be based on pure strategy, chance or a mixture of the two and usually have a goal which a player aims to achieve.
        • Strategy game – game (e.g. computer, video or board game) in which the players' uncoerced, and often autonomous decision-making skills have a high significance in determining the outcome. Almost all strategy games require internal decision tree style thinking, and typically very high situation awareness.
        • Two-player game – game played by just two players, usually against each other.
      • Sport – form of play, but sport is also a category of entertainment in its own right (see immediately below for description)
  • Sport – organized, competitive, entertaining, and skillful activity requiring commitment, strategy, and fair play, in which a winner can be defined by objective means. It is governed by a set of rules or customs. Chess is recognized as a sport by the International Olympic Committee.
    • Mind sport – game where the outcome is determined mainly by mental skill, rather than by pure chance.
      

Chess equipment

Essential equipment

• Chessboard – board with 64 squares (eight rows and eight columns) arranged in two alternating colors (light and dark). The colors are called "black" and "white", although the actual colors vary: usually they are dark green and buff for boards used in competition, and often natural shades of light and dark woods for home boards. Chess boards can be built into chess tables, or dispensed with (along with pieces) if playing mental chess, computer chess, Internet chess and sometimes correspondence chess.
  • Rank – horizontal row of squares on the chessboard.
  • File – vertical (i.e. in the direction from one player to the other) column of squares on the chessboard.

A Staunton chess set

• Chess set – all the pieces required to play a game of chess. Chess sets come in various materials and styles, and some are considered collectors' items and works of art. The most popular style for competitive play is the Staunton chess set, named after Howard Staunton. The relative values given are approximate and depend on the game situation.
  • Chess pieces – two armies of 16 chess pieces, one army white, the other black. Each player controls one of the armies for the entire game. The pieces in each army include:
    • 1 king – most important piece, and one of the weakest (until the endgame). The object of the game is checkmate, by placing the enemy king in check in a way that it cannot escape capture in the next move. On the top of the piece is a cross.
    • 1 queen – most powerful piece in the game, with a relative value of 9 points. The top of the piece is crown-like. Official tournament chess sets have 2 queens of each color, to deal with pawns being promoted 
    • 2 rooks – look like castle towers and have a relative value of 5 points each.
    • 2 bishops – stylized after mitres (bishops' hats), and have a relative value of 3 points each.
    • 2 knights – usually look like horse heads and have a relative value of 3 points each.
    • 8 pawns – smallest pieces in the game, each topped by a ball. Pawns have a relative value of 1 point each.
      

Specialized equipment

Digital game clock

• Game clock – dual timer used to monitor each player's thinking time. Only the timer of the player who is to move is active. Used for speed chess, and to regulate time in tournament games.
• Score sheet and writing implement – Tournament games require scores to be kept, and many players like to record other games for later analysis.
  

Rules of chess

Rules of chess – rules governing the play of the game of chess.

• White and Black in chess – one set of pieces is designated "white" and the other is designated "black". White moves first. Some older sets had white and red.
• Cheating in chess – methods that have been used to gain an unfair advantage by breaking the rules.
  

Initial set up

• Initial set up – initial placement of the pieces on the chessboard before any moves are made.
  

Moves

• Capture – move of a piece to a square occupied by an opposing piece, which is removed from the board and from play.
• Check – situation in which the king would be subject to capture (but the king is never actually captured).
• Checkmate – a winning move which makes capture of the opposing king inevitable.
  

How each piece moves

• Moving a pawn – pawns move straight forward one space at a time, but capture diagonally (within a one-square range). On its first move, a pawn may move two squares forward instead (with no capturing allowed in a two-square move). Also, pawns are subject to the en passant and promotion movement rules (see below).
  • En passant – on the very next move after a player moves a pawn two squares forward from its starting position, an opposing pawn that is guarding the skipped square may capture the pawn (taking it "as it passes"), by moving to the passed square as if the pawn had stopped there.
  • Pawn promotion – when a pawn reaches its eighth rank it is exchanged for the player's choice of a queen, rook, bishop or knight (usually a queen, since it is the most powerful piece).
• Moving a knight – knights move two squares horizontally and one square vertically, or two squares vertically and one square horizontally, jumping directly to the destination while ignoring intervening spaces.
• Moving a bishop – bishops move any distance in a straight line in either direction along squares connected diagonally. One bishop in each army moves diagonally on white squares only, and the other bishop is restricted to moving along black squares.
• Moving a rook – rook may move any distance along a rank or a file (forward, backward, left, or right), and can also be used for castling (see below).
  • Castling – special move available to each player once in the game (with restrictions) where the king is moved two squares to the left or right and the rook on that side is moved to the other side of the king.
• Moving the queen – queen can move like a rook or like a bishop (horizontally, vertically, or diagonally), but no castling.
• Moving the king – king may move one square in any direction, but may not move into check. It may also make a special move called "castling" (see above).
  

End of the game

• Resigning – a player may end the game by resigning, which cedes victory to the opponent.
• Checkmate – object of the game – a king is in check and has no move to get out of check, losing the game.
• Draw – neither side wins or loses. In competition this usually counts as a half-win for each player.
  • Draw by agreement – players may agree that the game is a draw.
  • Stalemate – if the player whose turn it is to move has no legal move and is not in check, the game is a draw by stalemate.
  • Fifty-move rule – if within the last fifty moves by both sides, no pawn has moved and there have been no captures, a player may claim a draw.
  • Threefold repetition – if the same position has occurred three times with the same player to move, a player may claim a draw.
    • Perpetual check – situation in which one king cannot escape an endless series of checks but cannot be checkmated. This was formerly a rule of chess to result in a draw, and still used informally, but superseded by the threefold repetition rule and fifty-move rule, which make it implicit.
      

Competition rules and other features

• Adjournment – play stops, and the game is resumed later. This has become rare since the advent of computer analysis of chess games.
• Chess notation – system of recording chess moves.
  • Algebraic chess notation – most common method of recording moves.
  • Descriptive chess notation – superseded method of recording moves, it was widely used, especially in English- and Spanish-speaking countries, and is still sometimes seen.
• Draw by agreement – the two players agree to call the game a draw, as neither is likely to win.
• Time control – each player must complete either a specified number of moves or all of his moves before a certain time elapses on his game clock.
• Touch-move rule – if a player touches his own piece, he must move it if it has a legal move. If he touches an opponent's piece, he must capture it if he can legally.
  

Minor variants

• Blindfold chess – one or both players play without seeing the board and pieces.
• Chess handicap – one of the players gives a handicap to the other player, usually starting the game without a certain piece.
• Fast chess – chess played with a time control limiting each player to a specified time of 60 minutes or less (can be as low as 1 minute).
  

Gameplay

• Blunder – very bad move.
• Candidate move – move that upon initial observation of the position, warrants further analysis. Spotting these moves is the key to higher-level play.
• Compensation – having positional advantages in spite of material disadvantages.
• Chess handicap – way to enable a weaker player to have a chance of winning against a stronger one. There are a variety of such handicaps, such as material odds (the stronger player surrenders a certain piece or pieces), extra moves (the weaker player has an agreed number of extra moves at the beginning of the game), extra time on the chess clock, and special conditions (such as requiring the odds-giver to deliver checkmate with a specified piece or pawn). Various permutations of these, such as "pawn and two moves", are also possible.
• Chess piece relative value – relative value of chess pieces, based on their relative power.
• Premove – used in fast online games, it refers to a player making his next move while his opponent is thinking about his move. After the opponent's move, the premove will be made, if legal, taking only 0.1 seconds on the game clock.
• Priyome – typical maneuver or technique in chess.
• Ply – half-turn, that is, one player's portion of a turn.
• Tempo – a "unit" similar to time, equal to one chess move, e.g. to lose a tempo is to waste a move or give the opponent the opportunity of an extra move. Sometimes a player may want to lose a tempo.
  

General situations

• En prise – when an unguarded piece is in position to be captured.
• Initiative – situational advantage in which a player can make threats that cannot be ignored, forcing the opponent to use his turns to respond to threats rather than make his own.
• Transposition – sequence of moves resulting in a position which may also be reached by another common sequence of moves. Transpositions are particularly common in openings, where a given position may be reached by different sequences of moves. Players sometimes use transpositions deliberately in order to avoid variations they dislike, lure opponents into unfamiliar or uncomfortable territory or simply to worry opponents.
• Time trouble – having little thinking time left in a timed game, thereby increasing the likelihood of making weak or losing moves or overlooking strong or winning moves.
• Zugzwang – situation in which a player would prefer to pass and make no move, because he has no move that does not worsen his position.
  

Pawn structure

Pawn structure – describes features of the positions of the pawns. Pawn structure may be used for tactical or strategic effect, or both.

• Backward pawn – pawn that is not supported by other pawns and cannot advance.
• Connected pawns – pawns of the same color on adjacent files so that they can protect each other.
• Doubled pawns – two pawns of the same color on the same file, so that one blocks the other.
• Half-open file – file that has pawns of one color only.
• Isolated pawn – pawn with no pawns of the same color on adjacent files.
• Maróczy Bind – formation with white pawns on c4 and e4, after the exchange of White's d-pawn for Black's c-pawn.
• Open file – file void of pawns.
• Passed pawn – pawn that can advance to its eighth rank without being blocked by an opposing pawn and without the possibility of being captured by a pawn on an adjacent file.
  

Chess tactics

Chess tactics – a chess tactic is a move or sequence of moves which may result in tangible gain or limits the opponent's options. Tactics are usually contrasted with strategy, in which advantages take longer to be realized, and the opponent is less constrained in responding.

• Anti-computer tactics – tactics used by humans in games against computers that the program cannot handle very well
• Capture – to remove an opposing piece from the board by taking it with one of your own. Except in the case of an en passant capture, the capturing man replaces the captured man on its square. Also, a move that captures. Captures can be executed offensively or defensively.
• Combination – series of moves, often with an exchange or sacrifice, to achieve some advantage.
• Exchange – capturing a piece in return for allowing another piece to be captured.
  • The exchange – exchange of a bishop or knight for a rook. The rook is generally the stronger piece unless a player obtains other advantages for allowing the exchange.
• Flight square – square that the king can retreat to, if attacked.
  

Fundamental tactics

Fundamental tactics include:

• Battery – two or more pieces that can move and attack along a shared path, situated on the same rank, file, or diagonal; e.g., the queen and a bishop, or the queen and a rook, or both rooks, or the queen and both rooks.
• Block (blocking an attack) – interposing a piece between another piece and its attacker. When the piece being attacked is the king, this is blocking a check.
• Deflection – tactic that forces an opposing piece to leave the square, rank or file it occupies, thus exposing the king or a valuable piece.
• Discovered attack – moving a piece uncovers an attack by another piece along a straight line
• Fork – attack on two or more pieces by one piece
• Interference – blocking the line along which an enemy piece is defended, leaving it vulnerable to capture.
• Overloading – giving a defensive piece an additional defensive assignment which it cannot complete without abandoning its original defensive assignment.
• Pin – piece is under attack and either cannot legally move because it would put its king in check or should not move because it will allow an attack on a more valuable piece.
• Skewer – if a piece under attack moves it will allow an attack on another piece
• Undermining – capturing a defensive piece, leaving one of the opponent's pieces undefended or underdefended. Also known as "removal of the guard".
• X-ray – (1) synonym for skewer. The term is also sometimes used to refer to a tactic where a piece either (2) indirectly attacks an enemy piece through another piece or pieces or (3) defends a friendly piece through an enemy piece.
  

Offensive tactics

• Battery – two or more pieces that can move and attack along a shared path, situated on the same rank, file, or diagonal; e.g., the queen and a bishop, or the queen and a rook, or both rooks, or the queen and both rooks.
  • Alekhine's gun – formation named after the former World Chess Champion, Alexander Alekhine, which consists of placing the two rooks stacked one behind another and the queen at the rear.
• Cross-check – tactic in which a check is played in response to a check, especially when the original check is blocked by a piece that itself either delivers check or reveals a discovered check from another piece.
• Decoy – ensnaring a piece, usually the king or queen, by forcing it to move to a poisoned square with a sacrifice on that square.
• Deflection – forces an opposing piece to leave the square, rank or file it occupies, thus exposing the king or a valuable piece.
• Discovered attack – attack revealed when one piece moves out of the way of another.
  • Discovered check – discovered attack that is also a check
• Domination – occurs when a piece has a relatively wide choice of destination squares, but nevertheless cannot avoid being captured.
• Double attack – attack on two pieces at once, such as in a fork, or via a discovered attack where the piece that was blocked attacks one piece while the piece moving out of the way threatens another.
  • Double check – check delivered by two pieces at the same time. In chess notation, it is sometimes symbolized by "++".
• Fork – when a piece attacks two or more enemy pieces at the same time
• Interference – interrupting the line between an attacked piece and its defender by sacrificially interposing a piece. Opportunities for interference are rare because the defended object must be more valuable than the sacrificed piece, and the interposition must itself represent a threat.
• King walk – several successive movements of the king, usually in the endgame to get it from a safe square (where it was hiding during the middlegame) to a more active position. Not to be confused with "king hunt", where a player forces his opponent's king out of safety and chases it across the board with a series of checks.
• Outpost – square where a piece can attack the opponent's position without being attacked by enemy pawns. Knights are good pieces to occupy outposts.
• Overloading – giving a defensive piece an additional defensive assignment which it cannot complete without abandoning its original defensive assignment.
• Pawn promotion – moving a pawn to the back row to be promoted to a knight, a bishop, a rook, or a queen. While this is a rule, it is also a type of move, with tactical significance. Pawn promotion, or the threat of it, often decides the result of a chess endgame.
  • Underpromotion – promotion to a knight, bishop, or rook is known as an "underpromotion". Although these pieces are less powerful than the queen, there are some situations where it is advantageous to underpromote. For example, since the knight moves in a way which the queen cannot, knight underpromotions can be very useful, and are the most common type of underpromotion. Promoting to a rook or bishop is advantageous in cases where promoting to a queen would result in an immediate stalemate.
• Pawn storm – several pawns are moved in rapid succession toward the opponent's defenses.
• Pin – piece is under attack and either cannot legally move because it would put its king in check or should not move because it will allow an attack on a more valuable piece.
  • Absolute pin – pin against the king is called absolute since the pinned piece cannot legally move (as moving it would expose the king to check).
  • Relative pin – where the piece shielded by the pinned piece is a piece other than the king, but typically more valuable than the pinned piece.
  • Partial pin – when a rook or queen is pinned along a file or rank, or a bishop or queen is pinned along a diagonal
  • Situational pin – when a pinned piece is shielding a square and moving out of the way will allow the enemy to move there, resulting in a detrimental situation for the player of the pinned piece, such as checkmate.
• Sacrifice – move which deliberately allows the loss of material, either because the player can win the material back or deliver checkmate if it is taken (sham sacrifice or pseudosacrifice), or because the player judges he will have positional compensation (true or positional sacrifice).
  • Greek gift sacrifice – typical sacrifice of a bishop by White playing Bxh7+ or Black playing Bxh2+.
  • Queen sacrifice – sacrifice of the queen, invariably tactical in nature.
  • Plachutta – a piece sacrifices itself on a square where it could be captured by two different pieces in order to deflect them both from crucial squares.
• Skewer – attack upon two pieces in a line and is similar to a pin. In fact, a skewer is sometimes described as a "reverse pin"; the difference is that in a skewer, the more valuable piece is in front of the piece of lesser or equal value.
  • Absolute skewer – when the King is skewered, forcing him to move out of check, exposing the piece behind him in the line of attack.
  • Relative skewer – the skewered piece can be moved, but doesn't have to be (because it is not the King in check).
• Swindle – ruse by which a player in a losing position tricks his opponent, and thereby achieves a win or draw instead of the expected loss. It may also refer more generally to obtaining a win or draw from a clearly losing position.
• The exchange – see § Chess tactics above
• Triangulation – technique of making three moves to wind up in the same position while the opponent has to make two moves to wind up in the same position. The reason is to lose a tempo and put the opponent in zugzwang.
• Undermining – capturing a defensive piece, leaving one of the opponent's pieces undefended or underdefended. Also known as "removal of the guard".
• Windmill – repeated series of discovered checks which the opponent cannot avoid, winning large amounts of material.
• X-ray attack – indirect attack of a piece through another piece.
• Zwischenzug ("Intermediate move") – To make an intermediate move before the expected move to gain an advantage.
  

Checkmate patterns

Checkmate pattern – a particular checkmate. Some checkmate patterns occur sufficiently frequently, or are otherwise of such interest to scholars, that they have acquired specific names in chess commentary. Here are some of the most notorious:

• Back-rank checkmate – checkmate accomplished by a rook or queen on the opponent's first rank, because the king is blocked in by its own pieces.
• Bishop and knight checkmate – fundamental checkmate with a minimum amount of material. It is notoriously difficult to achieve.
• Boden's Mate – checkmate pattern characterized by a king being mated by two bishops on criss-crossing diagonals, with possible flight squares blocked by friendly pieces.
• Fool's mate – shortest possible checkmate, on Black's second move. It is rare in practice.
• Scholar's mate – checkmate in as few as four moves by a player accomplished by a queen supported by a bishop (usually) in an attack on the f7 or f2 square. It is fairly common at the novice level.
• Smothered mate – checkmate accomplished by only a knight because the king's own pieces occupy squares to which it would be able to escape.
  

Defensive tactics

• Artificial castling (also known as "castling by hand") – taking several moves to get the king to the position it would be in if castling could have been done.
• Block (blocking an attack) – interposing a piece between another piece and its attacker. When the piece being attacked is the king, this is blocking a check.
• Blockade – to block a passed pawn with a piece.
• Desperado – piece that seems determined to give itself up, typically either (1) to sell itself as dearly as possible in a situation where both sides have hanging pieces or (2) to bring about stalemate if it is captured (or in some instances, to force a draw by threefold repetition if it is not captured).
• Luft – German for "air", meaning squares available for the king to escape an attack, typically through a fortress.
• X-ray defense – indirect defense of a piece through another piece.
  

Possible responses to an attack

• Capture the attacking piece
• Move the attacked piece
• Block – interpose another piece in between the two
• Guard the attacked piece and permit an exchange
• Pin the attacking piece so the capture becomes illegal or unprofitable
• Use a zwischenzug
• Create a counter-threat
  

Chess strategy

Chess strategy – aspect of chess playing concerned with evaluation of chess positions and setting of goals and long-term plans for future play. While evaluating a position strategically, a player must take into account such factors as the relative value of the pieces on the board, pawn structure, king safety, position of pieces, and control of key squares and groups of squares (e.g. diagonals, open files, individual squares).

• Corresponding squares – usually used as a tool in king and pawn endgames, a pair of corresponding squares are such that if one king is on one of them, the opposing king needs to be on the other.
• Fianchetto – moving the pawn in front of the knight and placing the bishop on that square.
• Permanent brain – thinking when it is the opponent's turn to move.
• Prophylaxis – move that prevents some tactical moves by the opponent.
• First-move advantage in chess – theory that White's having the first move gives him an advantage.
  

Schools of chess

School of chess – group of players that share common ideas about the strategy of the game. There have been several schools in the history of modern chess. Today there is less dependence on schools – players draw on many sources and play according to their personal style.

• Modenese Masters – school of chess thought based on teachings of 18th century Italian masters, it emphasized an attack on the opposing king.
• Hypermodernism – school of thought based on ideas of some early 20th century masters. Rather than occupying the center of the board with pawns in the opening, control the center by attacking it with knights and bishops from the side.
  

Game phases

1. Chess opening – first phase of the game, where pieces are developed before the main battle begins.
2. Chess middlegame – second phase of the game, usually where the main battle is. Many games end in the middlegame.
3. Chess endgame – third and final phase of the game, where there are only a few pieces left.
   

Chess openings

Chess opening – group of initial moves of a chess game. Recognized sequences of opening moves are referred to as openings as finished by White, or defenses as finished by Black, but opening is also used as the general term.

• Checkmates in the opening – examples of a player being checkmated during the first few moves of the game (i.e. in the opening).
  • Fool's mate – also known as the Two-Move Checkmate, it is the quickest possible checkmate in chess. A prime example consists of the moves: 1.f3 e5 2.g4 Qh4#
  • Scholar's mate – checkmate achieved by the moves: 1.e4 e5 2.Qh5 Nc6 3.Bc4 Nf6? 4.Qxf7#. The moves might be played in a different order or in slight variation, but the basic idea is the same: the queen and bishop combine in a simple mating attack on f7 (or f2 if Black is performing the mate).
  • Smothered mate – checkmate delivered by a knight in which the mated king is unable to move because he is surrounded (or smothered) by his own pieces.
  • Back rank checkmate – checkmate delivered by a rook or queen along a back rank (that is, the row on which the pieces (not pawns) stand at the start of the game) in which the mated king is unable to move up the board because the king is blocked by friendly pieces (usually pawns) on the second rank (Burgess 2009:16).
  • Boden's mate – checkmating pattern in chess characterized by bishops on two criss-crossing diagonals (for example, bishops on a6 and f4 delivering mate to a king on c8), with possible flight squares for the king being occupied by friendly pieces. Most often the checkmated king has castled queenside, and is mated on c8 or c1.
  • Epaulette mate – checkmate where two parallel retreat squares for a checked king are occupied by his own pieces, preventing his escape. The most common Epaulette mate involves the king on his back rank, trapped between two rooks.
  • Légal's mate – chess opening trap, characterized by a queen sacrifice followed by checkmate with minor pieces if Black accepts the sacrifice. The trap is named after the French player Sire de Légal (1702–1792).
• Chess Informant
• Chess opening theory table
• Encyclopaedia of Chess Openings
• Gambit – sacrifice of material (usually a pawn) to gain a positional advantage (usually faster development of pieces)
• List of chess openings
  • List of chess openings named after people
  • List of chess openings named after places