Friends

The nature and objectives of the game of chess

The game of chess is played between two opponents who move their pieces on a square board.

The player with the light-coloured pieces (White) makes the first move, then the players move alternately, with the player with the dark-coloured pieces (Black) making the next move.

The objective of each player is to place the opponent’s king ‘under attack’ in such a way that the opponent has no legal move. The player who achieves this goal is said to have ‘checkmated’ the opponent’s king and to have won the game. The following are not allowed:

• leaving one’s own king under attack
• exposing one’s own king to attack
• ’capturing’ the opponent’s king

If the position is such that neither player can possibly checkmate the opponent’s king, the game is drawn.

The initial position of the pieces on the chessboard

The chessboard is composed of an 8 x 8 grid of 64 equal squares alternately light (the ‘white’ squares) and dark (the ‘black’ squares).

At the beginning of the game White has 16 light-coloured pieces (the ‘white’ pieces); Black has 16 dark-coloured pieces (the ‘black’ pieces). These pieces are as follows:

Piece	King	Queen	Rook	Bishop	Knight	Pawn
Number	1	1	2	2	2	8
Symbols

The initial position of the pieces on the chessboard is as follows:

A B C D E F G H 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1 A B C D E F G H

File

Vertical column of squares.

Rank

Horizontal row of squares.

Diagonal

A straight line of squares of the same colour, running from one edge of the board to an adjacent edge.

The moves of the pieces

It is not permitted to move a piece to a square occupied by a piece of the same colour.

If a piece moves to a square occupied by an opponent’s piece the latter is captured and removed from the chessboard as part of the same move.

A piece is said to attack an opponent’s piece if the piece could make a capture on that square.

A piece is considered to attack a square even if this piece is constrained from moving to that square because it would then leave or place the king of its own colour under attack.

Bishop

The bishop may move to any square along a diagonal on which it stands.

A B C D E F G H 8 O 8 7 O O 7 6 O O 6 5 O O 5 4 4 3 O O 3 2 O O 2 1 O O 1 A B C D E F G H

Rook

The rook may move to any square along the file or the rank on which it stands.

A B C D E F G H 8 O 8 7 O 7 6 O 6 5 O 5 4 O 4 3 O O O O O O O 3 2 O 2 1 O 1 A B C D E F G H

Queen

The queen may move to any square along the file, the rank or a diagonal on which it stands.

A B C D E F G H 8 O O 8 7 O O O 7 6 O O O 6 5 O O O 5 4 O O O O O O O 4 3 O O O 3 2 O O O 2 1 O O O 1 A B C D E F G H

When making these moves, the bishop, rook or queen may not move over any intervening pieces.

Knight

The knight may move to one of the squares nearest to that on which it stands but not on the same rank, file or diagonal.

A B C D E F G H 8 8 7 O 7 6 O O 6 5 O O 5 4 O O 4 3 3 2 O O 2 1 O O 1 A B C D E F G H

Pawn

The pawn may move:

• forward to the square immediately in front of it on the same file, provided that this square is unoccupied, or
• on its first move only the pawn may also advance two squares along the same file, provided that both squares are unoccupied, or
• the pawn may move to a square occupied by an opponent’s piece diagonally in front of it on an adjacent file, capturing that piece.

A B C D E F G H 8 8 7 7 6 6 5 5 4 O X O X 4 3 X O X 3 2 2 1 1 A B C D E F G H

En passant

A pawn occupying a square on the same rank as and on an adjacent file to an opponent’s pawn which has just advanced two squares in one move from its original square may capture this opponent’s pawn as though the latter had been moved only one square. This capture is only legal on the move following this advance and is called an ‘en passant’ capture.

A B C D E F G H 8 8 7 7 6 X 6 5 O 5 4 4 3 3 2 2 1 1 A B C D E F G H

Promotion

When a player, having the move, plays a pawn to the rank furthest from its starting position, they must exchange that pawn as part of the same move for a new queen, rook, bishop or knight of the same colour on the intended square of arrival. This is called the square of ‘promotion’.

• The player's choice is not restricted to pieces that have been captured previously.
• This exchange of a pawn for another piece is called promotion, and the effect of the new piece is immediate.

King

There are two different ways of moving the king:

• by moving to an adjoining square, or
• (once in the game) by ‘castling’.

A B C D E F G H 8 O O 8 7 O O O 7 6 6 5 5 4 O O O 4 3 O O 3 2 O O O 2 1 1 A B C D E F G H

Castling

This is a move of the king and either rook of the same colour along the player’s first rank, counting as a single move of the king and executed as follows: the king is transferred from its original square two squares towards the rook on its original square, then that rook is transferred to the square the king has just crossed.

Before black queenside castling	After black queenside castling
A B C D E F G H 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1 A B C D E F G H	A B C D E F G H 8 8 7 7 6 6 5 5 4 4 3 3 2 2 1 1 A B C D E F G H
Before white kingside castling	After white kingside castling

The right to castle has been lost:

• if the king has already moved, or
• with a rook that has already moved.

Castling is prevented temporarily:

• if the square on which the king stands, or the square which it must cross, or the square which it is to occupy, is attacked by one or more of the opponent's pieces, or
• if there is any piece between the king and the rook with which castling is to be effected.

Check

The king is said to be 'in check' if it is attacked by one or more of the opponent's pieces, even if such pieces are constrained from moving to the square occupied by the king (because they would then leave or place their own king in check).

No piece can be moved that will either expose the king of the same colour to check or leave that king in check.

The completion of the game

The game is won by the player:

• who has checkmated their opponent’s king.
• whose opponent declares they resign.

The game is drawn when:

• the player to move has no legal move and their king is not in check. The game is said to end in ‘stalemate’.
• a position has arisen in which neither player can checkmate the opponent’s king with any series of legal moves. The game is said to end in a ‘dead position’.
• there is agreement between the two players during the game, provided both players have made at least one move.

Variant: Chess960

Before a Chess960 game a starting position is randomly set up, subject to certain rules. After this, the game is played in the same way as regular chess. In particular, pieces and pawns have their normal moves, and each player's objective is to checkmate the opponent's king.

Starting position

The starting position for Chess960 must meet certain rules. White pawns are placed on the second rank as in regular chess. All remaining white pieces are placed randomly on the first rank, but with the following restrictions:

• the king is placed somewhere between the two rooks, and
• the bishops are placed on opposite-coloured squares, and
• the black pieces are placed opposite the white pieces.

There are 960 unique possible starting positions.

Chess960 castling rules

Chess960 allows each player to castle once per game, a move by potentially both the king and rook in a single move. However, a few interpretations of regular chess rules are needed for castling, because the regular rules presume initial locations of the rook and king that are often not applicable in Chess960.

In Chess960, depending on the pre-castling position of the castling king and rook, the castling manoeuvre is performed by one of these four methods:

1. double-move castling: by making a move with the king and a move with the rook, or
2. transposition castling: by transposing the position of the king and the rook, or
3. king-move-only castling: by making only a move with the king, or
4. rook-move-only castling: by making only a move with the rook.

Clarification

c-side castling

After c-side castling (notated as 0-0-0 and known as queenside castling in orthodox chess), the king is on the c-square (c1 for white and c8 for black) and the rook is on the d-square (d1 for white and d8 for black).

g-side castling

After g-side castling (notated as 0-0 and known as kingside castling in orthodox chess), the king is on the g-square (g1 for white and g8 for black) and the rook is on the f-square (f1 for white and f8 for black).

In some starting positions:

• the king or rook (but not both) does not move during castling.
• castling can take place as early as the first move.

All the squares between the king's initial and final squares (including the final square) and all the squares between the rook's initial and final squares (including the final square) must be vacant except for the king and castling rook.

In some starting positions, some squares can stay filled during castling that would have to be vacant in regular chess. For example, after c-side castling (0-0-0), it is possible to have a, b, and/or e still filled, and after g-side castling (0-0), it is possible to have e and/or h filled.

Glossary of terms in the Laws of Chess

adjourn

Instead of playing the game in one session it is temporarily halted and then continued at a later time.

algebraic notation

Recording the moves using a-h and 1-8 on the 8x8 board.

analyse

Where one or more players make moves on a board to try to determine what is the best continuation.

arbiter

The person(s) responsible for ensuring that the rules of a competition are followed.

attack

A piece is said to attack an opponent’s piece if the player’s piece can make a capture on that square.

black

There are 16 dark-coloured pieces and 32 squares called black. Or

When capitalised, this also refers to the player of the black pieces.

blitz

A game where each player’s thinking time is 10 minutes or less.

board

Short for chessboard.

Bronstein mode

See delay mode.

capture

Where a piece is moved from its square to a square occupied by an opponent’s piece, the latter is removed from the board.

castling

A move of the king towards a rook. See castling above.

In notation 0-0 kingside castling, 0-0-0 queenside castling.

check

Where a king is attacked by one or more of the opponent’s pieces. In notation +.

checkmate

Where the king is attacked and cannot parry the threat. In notation ++ or #.

chessboard

The 8x8 grid. See The initial position of the pieces on the chessboard above.

chess clock

A clock with two time displays connected to each other.

chess set

The 32 pieces on the chessboard.

Chess960

A variant of chess where the back-row pieces are set up in one of the 960 distinguishable possible positions.

clock

One of the two time displays.

cumulative (Fischer) mode

Where a player receives an extra amount of time (often 30 seconds) prior to each move.

dead position

Where neither player can mate the opponent’s king with any series of legal moves.

default time

The specified time a player may be late without being forfeited.

delay (Bronstein) mode

Both players receive an allotted ‘main thinking time’. Each player also receives a ‘fixed extra time’ with every move. The countdown of the main thinking time only commences after the fixed extra time has expired. Provided the player presses their clock before the expiration of the fixed extra time, the main thinking time does not change, irrespective of the proportion of the fixed extra time used.

diagonal

A straight line of squares of the same colour, running from one edge of the board to an adjacent edge.

draw

Where the game is concluded with neither side winning.

draw offer

Where a player may offer a draw to the opponent. This is indicated on the scoresheet with the symbol (=).

en passant

see en passant above.

exchange

Where a pawn is promoted. Or

Where a player captures a piece of the same value as their own and this piece is recaptured. Or

Where one player has lost a rook and the other has lost a bishop or knight.

explanation

A player is entitled to have a Law explained.

fair play

Whether justice has been done has sometimes to be considered when an arbiter finds that the Laws are inadequate.

file

A vertical column of eight squares on the chessboard.

Fischer mode

See cumulative mode.

flag

The device that displays when a time period has expired.

flag-fall

Where the allotted time of a player has expired.

forfeit

To lose the right to make a claim or move. Or 2. To lose a game because of an infringement of the Laws.

illegal

A position or move that is impossible because of the Laws of Chess.

increment

An amount of time (from 2 to 60 seconds) added from the start before each move for the player. This can be in either delay or cumulative mode.

kingside

The vertical half of the board on which the king stands at the start of the game.

made

A move is said to have been ‘made’ when the piece has been moved to its new square, the hand has quit the piece, and the captured piece, if any, has been removed from the board.

mate

Abbreviation of checkmate.

minor piece

Bishop or knight.

move

40 moves in 90 minutes, refers to 40 moves by each player. Or

having the move refers to the player’s right to play next. Or

White’s best move refers to the single move by White.

move-counter

A device on a chessclock which may be used to record the number of times the clock has been pressed by each player.

normal means

Playing in a positive manner to try to win; or, having a position such that there is a realistic chance of winning the game other than just flag-fall.

over-the-board

The Laws cover only this type of chess, not internet, nor correspondence, and so on.

piece

One of the 32 figurines on the board. Or

A queen, rook, bishop or knight.

press the clock

The act of pushing the button or lever on a chess clock which stops the player’s clock and starts that of their opponent.

promotion

Where a pawn reaches the eighth rank and is replaced by a new queen, rook, bishop or knight of the same colour.

queen

As in queen a pawn, meaning to promote a pawn to a queen.

queenside

The vertical half of the board on which the queen stands at the start of the game.

quickplay finish

The last part of a game where a player must complete an unlimited number of moves in a finite time.

rank

A horizontal row of eight squares on the chessboard.

rapid chess

A game where each player’s thinking time is more than 10 minutes, but less than 60.

repetition

A player may claim a draw if the same position occurs three times.

A game is drawn if the same position occurs five times.

resigns

Where a player gives up, rather than play on until mated.

result

Usually the result is 1-0, 0-1 or ½-½. In exceptional circumstances both players may lose (Article 11.8), or one score ½ and the other 0. For unplayed games the scores are indicated by +/- (White wins by forfeit), -/+ (Black wins by forfeit), -/- (Both players lose by forfeit).

sealed move

Where a game is adjourned the player seals their next move in an envelope.

scoresheet

A paper sheet with spaces for writing the moves. This can also be electronic.

screen

An electronic display of the position on the board.

spectators

People other than arbiters or players viewing the games. This includes players after their games have been concluded.

standard chess

A game where each player’s thinking time is at least 60 minutes.

stalemate

Where the player has no legal move and their king is not in check.

square of promotion

The square a pawn lands on when it reached the eighth rank.

time control

The regulation about the time the player is allotted. For example, 40 moves in 90 minutes, all the moves in 30 minutes, plus 30 seconds cumulatively from move 1. Or

A player is said ‘to have reached the time control’, if, for example they have completed the 40 moves in less than 90 minutes.

time period

A part of the game where the players must complete a number of moves or all the moves in a certain time.

vertical

The 8th rank is often thought as the highest area on a chessboard. Thus each file is referred to as ‘vertical’.

white

There are 16 light-coloured pieces and 32 squares called white. Or

When capitalised, this also refers to the player of the white pieces.

50-move rule

A player may claim a draw if the last 50 moves have been completed by each player without the movement of any pawn and without any capture.

75-move rule

The game is drawn if the last 75 moves have been completed by each player without the movement of any pawn and without any capture.