Chessboard

A chessboard is the type of used for the game of chess, on which the chess pawns and are placed. A chessboard is usually square in shape, with an alternating pattern of squares in two colours. Though usually played on a surface, a tangible board is not a requirement to play the game. Traditionally wooden boards are made of unstained light and dark brown woods. To reduce cost, many boards are made with veneers of more expensive woods glued to an inner piece of plywood or chipboard. A variety of colours combinations are used for plastic, vinyl, and silicone boards. Common dark-light combinations are black and white, as well as brown, green or blue with buff or cream. Materials vary widely; while wooden boards are generally used in high-level games; vinyl, plastic, and cardboard are common for less important tournaments and matches and for home use. 
Decorative glass and marble boards are rarely permitted for games conducted by national or international chess federations. When they are permitted, they must meet various criteria (see the text on FIDE regulations below)
In western chess the board has a square shape, with its side being divided into eight parts, resulting in a total of sixty-four squares. For variants, the total number of squares may range from nine to one hundred and twelve. Each individual square of the board can be identified using chess notation, which may be descriptive, algebraic, or numeric. For two-dimensional boards, each horizontal row of squares is called a ', each vertical column of squares is called a ', and each oblique line of squares of the same colour is called a "".
History and evolution.
Board games have been known since ancient history, with the oldest records being paintings in mastabas of the First and Third Dynasties of Egypt (3100–2700 BC). The first known version of chess appeared around the 6th century in India and was called chaturanga, played on a board of the game Ashtapada. This board was monochromatic and divided into eight columns by eight rows, with special marks called "castles" in the first, fourth, fifth, and eighth squares of the a-, d-, e-, and h-columns, which served a function in Ashtapada, but not in chaturanga.
After arriving in Ancient Persia, the board was adapted to the new variants of chess, in which more columns and rows were included. One of the variants of the time, Tamerlane chess, had eleven columns by ten rows and two extra squares to the right side of the second row of the player, called "citadels", which held a special function in the game.
In the 10th century, chess arrived in Europe and the board acquired its characteristic recognisable chequered pattern used at the time in draughts, which had a smaller 5×5 board. This change proved particularly useful for diagonal movements, now highlighted by the continuous sequence of same-coloured squares in the diagonals, facilitating the movement of the recently added bishop and queen.
The Libro de los juegos (1283) contains a description of the chessboard, mentioning eight rows and columns as the ideal number, with the 10×10 board being too tiresome and the 6×6 board being too quick for the practice of chess. Other innovations of the time were cylindrical boards for the practice of variants such as cylinder chess and the convention that the first square of the far right column should be light-coloured, endorsed by Pedro Damiano in the end of the 15th century. More recently, some varieties have employed three-dimensional boards, in which the third dimension is usually another two-dimensional board. The Raumschach variant utilises five boards of twenty-five squares each, totalising 125 squares. Another noteworthy variant, "Star Trek" Chess, utilises a board of sixty-four squares divided into seven levels.
In 2003, the ex-world champion Garry Kasparov faced the chess engine X3D Fritz in a series of four matches in a virtual environment, where the computer-generated board hovered in the air in front of Kasparov, who used special glasses. As such, this was the first man–machine game of chess performed in a completely simulated environment.
Manufacture.
Chessboards have been made from numerous materials over the years, such as ebony, ivory, marble, metal, glass, and plastic. They can also be found as decorative elements in plazas, gardens, and living rooms.
For international or continental championships, FIDE's regulations state that wooden boards should be used. For other FIDE tournaments, wood, plastic, or cardboard boards may be used, and the board should be rigid in all instances. The board may also be made of marble, as long as there is an appropriate contrast between the light and dark squares. The finishing should be neutral or frosted but never shiny. The squares should be from 5 to 6.5 cm in length and the proportion between the squares and the pieces should be so that the side of a square is twice the diameter of a pawn's base. If the table and the board are two separate pieces, the latter must be fixed as to avoid its movement during the match.
Board notation.
The standard contemporary way to record moves and refer to the squares of the chessboard is algebraic chess notation The files are identified by the letters "a" to "h", from left to right from the white player's point of view, and the ranks by the numbers "1" to "8", with 1 being closest to the white player. Each square on the board is identified by a unique coordinate pairing, from a1 to h8.
In the older descriptive chess notation, the files are labelled by the piece originally occupying its first rank (e.g. queen, , ), and ranks by the numbers "1" to "8" from each player's point of view, depending on the move being described. This method is no longer commonly used. FIDE stopped using descriptive notation in 1981.
Numeric notation assigns numbers to both files and ranks, with rank 1 being the one closest to the player with the white pieces. The file leftmost to the white player ("a" in algebraic notation and "QR" in descriptive notation) is file one and the rightmost to them ("h" in algebraic notation and "KR" in descriptive notation) is file eight.
Boards and variants of chess.
The usage of chessboards with various shapes goes back to the Persian origins of the game in the 10th century, when the book "Muraj adh-dhahab" (Board of the Gods) described six different variants of chess, including circular and cylindrical chess. Another exotic format is used in hexagonal chess, which utilises a hexagonal board with three different colours for its 91 squares.
Boards of different sizes have also been used since the 10th century, with one of the first records being Tamerlane chess, with eleven columns by ten rows. The game originated in Persia and its board contains a peculiar element in the form of the addition of a square to the right of the second row of each player, called a citadel, and which served the purpose of being a refuge for the king and in some cases reaching a draw. Due to the widespread creation of new variants, a wide variety of sizes can be found. In 1617, Pietro Carrera proposed a variant that received his name, Carrera's Chess, with a 10×8 board, later used in other variants such as Capablanca Chess and Gothic Chess. Other sizes, with ten rows and ten columns, are used in Omega Chess and Grand Chess. Los Alamos chess, on the other hand, uses a smaller board with 36 squares.
Shogi and janggi, the Japanese and Korean variants of chess respectively, also have different sizes. The former employs a board with nine columns by nine rows, while the latter uses one with eight columns by nine rows. In both janggi and xiangqi the pieces move through the edges of the squares and the board has other components. In these boards, the d1-, e1-, d2-, and e2-squares, for the whites, and the d7-, e7-, d8-, and e8-squares, for the blacks, are called a Palace or a Fortress and have the function of restricting the movement of the king to this area. Additionally, in xiangqi there is a space between the fourth and fifth rows, called a Celestial River, which restricts the movement of some pieces such as the elephant.
Many varieties of chess also use more than a single chessboard per match, for different reasons. Bughouse chess, for example, is played by four players disputing two simultaneous matches in separate boards. Alice Chess is a popular variant which, although can be played in a single chessboard, is usually played in two to facilitate the movement of pieces between the boards. Other variants such as Raumschach utilise extra boards to simulate the third dimension. While Raumschach uses five boards, extending the game's third dimension through five squares, other variants may use from one to seven extra boards. "Star Trek" Chess uses an ingenious board with movable parts divided into seven levels. In the initial position each player occupies two of the small movable boards with four squares used for attacking. The whites start in the lower level, using attack boards connected to this level and the first two rows of the board, while the blacks start at the top, using the attack boards and first two rows of the third level.
Other representations.
The game of chess has been represented in the arts since its origin in Asia. Chessboards usually had considerable artistic value, being made of noble materials such as ebony and ivory, and in large sizes. Many of these pieces were offered to churches as relics. The book Liber miraculorum sancte Fidis tells a story in which a nobleman, after miraculously escaping from prison, is forced to carry a chessboard until a sanctuary as gesture of gratitude. However, more frequently there are stories in which the chessboard is used as a weapon. The French tale of Ogier the Dane reports how the son of Charlemagne brutally kills one of Ogier's sons with a chessboard after losing a match, although there are no evidences confirming the veracity of the story.
In 1250 a sermon called "Quaedam moralitas de scaccario per Innocentium papum" (The Innocent Morality) showed the world as being represented by a chessboard, with the white and black squares representing the two conditions of life and death or praise and censure over which the pieces, representing humanity, would confront each other in the adversities of the game, symbolising life.
Due to its simple geometry, the chessboard grid is often used in mathematical puzzles or problems unrelated to chess. Examples include the wheat and chessboard problem, the mutilated chessboard problem, and the angel problem.