Checkers (

American English American English, sometimes called United States English or U.S. English, is the set of varieties of the English language native to the United States. English is the most widely spoken language in the United States and in most circumstances ...

), also known as draughts (;

British English British English (BrE, en-GB, or BE) is, according to Oxford Dictionaries, "English as used in Great Britain, as distinct from that used elsewhere". More narrowly, it can refer specifically to the English language in England, or, more broadly ...

), is a group of

strategy Strategy (from Greek στρατηγία ''stratēgia'', "art of troop leader; office of general, command, generalship") is a general plan to achieve one or more long-term or overall goals under conditions of uncertainty. In the sense of the " ar ...

board game Board games are tabletop games that typically use . These pieces are moved or placed on a pre-marked board (playing surface) and often include elements of table, card, role-playing, and miniatures games as well. Many board games feature a com ...

s for two players which involve diagonal moves of uniform game pieces and mandatory captures by jumping over opponent pieces. Checkers is developed from

alquerque Alquerque (also known as Qirkat from ar, القرقات) is a strategy board game that is thought to have originated in the Middle East. It is considered to be the parent of draughts (US: checkers) and Fanorona. History The game first appears ...

. The term "checkers" derives from the

checkered Check (also checker, Brit: chequer) is a pattern of modified stripes consisting of crossed horizontal and vertical lines which form squares. The pattern typically contains two colours where a single checker (that is a single square within the chec ...

board which the game is played on, whereas "draughts" derives from the verb "to draw" or "to move". The most popular forms of checkers in Anglophone countries are American checkers (also called

English draughts English draughts (British English) or checkers (American English), also called straight checkers or simply draughts, is a form of the strategy board game checkers (or draughts). It is played on an 8×8 checkerboard with 12 pieces per side. The ...

), which is played on an 8×8

checkerboard A checkerboard (American English) or chequerboard (British English; see spelling differences) is a board of checkered pattern on which checkers (also known as English draughts) is played. Most commonly, it consists of 64 squares (8×8) of alte ...

;

Russian draughts Russian draughts (also known as Shashki or Russian shashki) is a variant of draughts (checkers) played in Russia and some parts of the former USSR, as well as parts of Eastern Europe and Israel. Rules As in all draughts variants, Russian draugh ...

, Turkish draughts both on an 8x8 board, and

International draughts International draughts (also called international checkers or Polish draughts) is a strategy board game for two players, one of the variants of draughts. The gameboard comprises 10×10 squares in alternating dark and light colours, of which on ...

, played on a 10×10 board – the latter is widely played in many countries worldwide. There are many other variants played on 8×8 boards.

Canadian checkers Canadian checkers (or Canadian draughts) is a variant of the strategy board game draughts. It is one of the largest draughts games, played on a 12×12 checkered board with 30 game pieces per player. History The game was invented by the French se ...

and Singaporean/Malaysian checkers (also locally known as ''dum'') are played on a 12×12 board. American checkers was weakly solved in 2007 by a team of Canadian computer scientists led by

Jonathan Schaeffer Jonathan Herbert Schaeffer (born 1957) is a Canadian researcher and professor at the University of Alberta and the former Canada Research Chair in Artificial Intelligence. He led the team that wrote Chinook, the world's strongest American ch ...

. From the standard starting position, perfect play by each side would result in a draw.

General rules

Checkers is played by two opponents on opposite sides of the game board. One player has dark pieces (usually black); the other has light pieces (usually white or red). Players alternate turns. A player cannot move an opponent's pieces. A move consists of moving a piece diagonally to an adjacent unoccupied square. If the adjacent square contains an opponent's piece, and the square immediately beyond it is vacant, the piece may be captured (and removed from the game) by jumping over it. Only the dark squares of the checkerboard are used. A piece can only move diagonally into an unoccupied square. When capturing an opponent's piece is possible, capturing is mandatory in most official rules. If the player does not capture, the other player can remove the opponent's piece as a penalty (or muffin), and where there are two or more such positions the player forfeits pieces that cannot be moved (although some rule variations make capturing optional). In almost all variants, the player without pieces remaining, or who cannot move due to being blocked, loses the game.

Pieces

Man

An uncrowned piece (''man'') moves one step diagonally forwards and captures an adjacent opponent's piece by jumping over it and landing on the next square. Multiple enemy pieces can be captured in a single turn provided this is done by successive jumps made by a single piece; the jumps do not need to be in the same line and may "zigzag" (change diagonal direction). In American checkers, men can jump only forwards; in

international draughts International draughts (also called international checkers or Polish draughts) is a strategy board game for two players, one of the variants of draughts. The gameboard comprises 10×10 squares in alternating dark and light colours, of which on ...

and

, men can jump both forwards and backwards.

King

When a man reaches the farthest row forward, known as the ''kings row'' or ''crown head'', it becomes a ''king''. It is marked by placing an additional piece on top of, or ''crowning'', the first man. The king has additional powers, including the ability to move backwards and, in variants where men cannot already do so, capture backwards. Like a man, a king can make successive jumps in a single turn, provided that each jump captures an enemy piece. In international draughts, kings (also called ''flying kings'') move any distance along unblocked diagonals. They may capture an opposing man any distance away by jumping to any of the unoccupied squares immediately beyond it. Because jumped pieces remain on the board until the turn is complete, it is possible to reach a position in a multi-jump move where the flying king is blocked from capturing further by a piece already jumped. Flying kings are not used in American checkers; a king's only advantage over a man is the additional ability to move and capture backwards.

Naming

In most non-English languages (except those that acquired the game from English speakers), checkers is called ''dame'', ''dames'', ''damas'', or a similar term that refers to ladies. The pieces are usually called ''men'', ''stones'', "peón" (pawn) or a similar term; men promoted to kings are called ''dames'' or ladies. In these languages, the

queen Queen or QUEEN may refer to: Monarchy * Queen regnant, a female monarch of a Kingdom ** List of queens regnant * Queen consort, the wife of a reigning king * Queen dowager, the widow of a king * Queen mother, a queen dowager who is the mother ...

in chess or in card games is usually called by the same term as the kings in checkers. A case in point includes the Greek terminology, in which checkers is called "ντάμα" (dama), which is also one term for the queen in chess.

History

Ancient games

Similar games have been played for millennia. A board resembling a checkers board was found in Ur dating from 3000 BC. In the

British Museum The British Museum is a public museum dedicated to human history, art and culture located in the Bloomsbury area of London. Its permanent collection of eight million works is among the largest and most comprehensive in existence. It documen ...

are specimens of ancient Egyptian checkerboards, found with their pieces in burial chambers, and the game was played by the pharaoh

Hatshepsut Hatshepsut (; also Hatchepsut; Egyptian: '' ḥꜣt- špswt'' "Foremost of Noble Ladies"; or Hatasu c. 1507–1458 BC) was the fifth pharaoh of the Eighteenth Dynasty of Egypt. She was the second historically confirmed female pharaoh, af ...

. Plato mentioned a game, πεττεία or ''petteia'', as being of Egyptian origin, and Homer also mentions it. The method of capture was placing two pieces on either side of the opponent's piece. It was said to have been played during the Trojan War. The

Romans Roman or Romans most often refers to: * Rome, the capital city of Italy * Ancient Rome, Roman civilization from 8th century BC to 5th century AD * Roman people, the people of ancient Rome *''Epistle to the Romans'', shortened to ''Romans'', a let ...

played a derivation of petteia called '' latrunculi'', or the game of the Little Soldiers. The pieces, and sporadically the game itself, were called ''calculi'' (''pebbles'').

Alquerque

An Arabic game called ''Quirkat'' or ''al-qirq'', with similar play to modern checkers, was played on a 5×5 board. It is mentioned in the tenth-century work

Kitab al-Aghani ''Kitab al-Aghani'' ( ar, كتاب الأغاني, kitāb al-‘aghānī, The Book of Songs), is an encyclopedic collection of poems and songs that runs to over 20 volumes in modern editions, attributed to the 10th-century Arabic writer Abu al-F ...

. Al qirq was also the name for the game that is now called nine men's morris. Al qirq was brought to Spain by the Moors, where it became known as ''

Alquerque Alquerque (also known as Qirkat from ar, القرقات) is a strategy board game that is thought to have originated in the Middle East. It is considered to be the parent of draughts (US: checkers) and Fanorona. History The game first appears ...

'', the Spanish derivation of the Arabic name. The rules are given in the 13th-century book ''

Libro de los juegos The ''Libro de los juegos'' (Spanish: "Book of games"), or ''Libro de axedrez, dados e tablas'' ("Book of chess, dice and tables", in Old Spanish), was a Spanish translation of Arabic texts on chess, dice and tables (backgammon forebears) games ...

''. In about 1100, probably in the south of France, the game of Alquerque was adapted using

backgammon Backgammon is a two-player board game played with counters and dice on tables boards. It is the most widespread Western member of the large family of tables games, whose ancestors date back nearly 5,000 years to the regions of Mesopotamia and P ...

pieces on a

chessboard A chessboard is a used to play chess. It consists of 64 squares, 8 rows by 8 columns, on which the chess pieces are placed. It is square in shape and uses two colours of squares, one light and one dark, in a chequered pattern. During play, the b ...

. Each piece was called a "fers", the same name as the

chess queen The queen (♕, ♛) is the most powerful piece in the game of chess. It can move any number of squares vertically, horizontally or , combining the powers of the rook and bishop. Each player starts the game with one queen, placed in the middle o ...

, as the move of the two pieces was the same at the time.

Crowning

The rule of crowning was used by the 13th century, as it is mentioned in the Philippe Mouskés's ''Chronique'' in 1243 when the game was known as ''Fierges'', the name used for the

(derived from the Persian ''ferz'', meaning royal counsellor or vizier). The pieces became known as "dames" when that name was also adopted for the chess queen. The rule forcing players to take whenever possible was introduced in France in around 1535, at which point the game became known as ''Jeu forcé'', identical to modern American checkers. The game without forced capture became known as ''Le jeu plaisant de dames'', the precursor of international checkers. The 18th-century English author

Samuel Johnson Samuel Johnson (18 September 1709 – 13 December 1784), often called Dr Johnson, was an English writer who made lasting contributions as a poet, playwright, essayist, moralist, critic, biographer, editor and lexicographer. The ''Oxford D ...

wrote a foreword to a 1756 book about checkers by William Payne, the earliest book in English about the game.

Invented variants

* Blue and Gray: On a 9×9 board, each side has 17 guard pieces that move and jump in any direction, to escort a captain piece which races to the centre of the board to win. *

Cheskers Cheskers is a variant of checkers and chess invented by Solomon Golomb in 1948. Rules Pieces * Pawns move as pieces in checkers: they move, without taking, one square diagonally forward, but take by jumping two squares diagonally forward over ...

: A variant invented by

Solomon Golomb Solomon (; , ),, ; ar, سُلَيْمَان, ', , ; el, Σολομών, ; la, Salomon also called Jedidiah ( Hebrew: , Modern: , Tiberian: ''Yăḏīḏăyāh'', "beloved of Yah"), was a monarch of ancient Israel and the son and succe ...

. Each player begins with a

bishop A bishop is an ordained clergy member who is entrusted with a position of authority and oversight in a religious institution. In Christianity, bishops are normally responsible for the governance of dioceses. The role or office of bishop is ca ...

and a

camel A camel (from: la, camelus and grc-gre, κάμηλος (''kamēlos'') from Hebrew or Phoenician: גָמָל ''gāmāl''.) is an even-toed ungulate in the genus ''Camelus'' that bears distinctive fatty deposits known as "humps" on its back. C ...

(which jumps with coordinates (3,1) rather than (2,1) so as to stay on the black squares), and men reaching the back rank promote to a bishop, camel, or king. *

Damath Damath is a two-player educational board game combining the board game "DieMath" and math. It is used as a teaching tool for both elementary and high school mathematics. Every piece has a corresponding number and each even (white) square on board ...

: A variant utilising math principles and numbered chips popular in the Philippines. *

Dameo Dameo is an abstract strategy board game for two players invented by Christian Freeling in 2000. It is a variant of the game draughts (or checkers) and is played on an 8×8 checkered gameboard. Game rules Dameo is played on an 8×8 checkerboard ...

: A variant played on an 8×8 board that utilizes all 64 squares and has diagonal and orthogonal movement. A special "sliding" move is used for moving a line of checkers similar to the movement rule in Epaminondas. By

Christian Freeling Christian Freeling (born 1 February 1947, in Enschede, Netherlands) is a Dutch game designer and inventor of abstract strategy games, notably Dameo, Grand Chess, Havannah, and Hexdame. Freeling's designs cover a range of game types. Several ...

(2000). *

Hexdame Hexdame (or HexDame) is a strategy board game for two players invented by Christian Freeling in 1979. The game is a literal adaptation of the game international draughts (checkers or ''Dame''In most non-English languages, draughts is called ''dame ...

: A literal adaptation of

to a hexagonal gameboard. By Christian Freeling (1979). *

Lasca Lasca (also called Laska or Laskers) is a draughts (or checkers) variant, invented by the second World Chess Champion Emanuel Lasker (1868–1941). Lasca is derived from English draughts English draughts (British English) or checkers (Ameri ...

: A checkers variant on a 7×7 board, with 25 fields used. Jumped pieces are placed under the jumper, so that towers are built. Only the top piece of a jumped tower is captured. This variant was invented by World Chess Champion Emanuel Lasker. *

Philosophy shogi checkers Philosophy shogi checkers (哲学飛将碁Board and pieces are displayed at Inoue Enryo Memoriam Museum at Hakusan campus of Toyo University (December 21, 2011).) is a board game similar to English draughts, invented by Inoue Enryō, Japanese phil ...

: A variant on a 9×9 board, game ending with capturing opponent's king. Invented by

Inoue Enryō was a Japanese philosopher, Shin Buddhist priest and reformer, educator, and royalist. A key figure in the reception of Western philosophy, the emergence of modern Buddhism, and the permeation of the imperial ideology during the second half of ...

and described in Japanese book in 1890. * Suicide checkers (also called ''Anti-Checkers'', ''Giveaway Checkers'' or ''Losing Draughts''): A variant where the objective of each player is to lose all of their pieces. * Tiers: A complex variant which allows players to upgrade their pieces beyond kings. * Vigman's draughts: Each player has 24 pieces (two full sets) – one on the light squares, a second set on dark squares. Each player plays two games simultaneously: one on light squares, the other on dark squares. The total result is the sum of results for both games.

Computer checkers

Lefty_the_Robot_-_First_Checker_Playing_Robot_1983

American checkers (English draughts) has been the arena for several notable advances in

game artificial intelligence In video games, artificial intelligence (AI) is used to generate responsive, adaptive or intelligent behaviors primarily in non-player characters (NPCs) similar to human-like intelligence. Artificial intelligence has been an integral part of vid ...

. In 1951

Christopher Strachey Christopher S. Strachey (; 16 November 1916 – 18 May 1975) was a British computer scientist. He was one of the founders of denotational semantics, and a pioneer in programming language design and computer time-sharing.F. J. Corbató, et al., T ...

wrote the first video game program on checkers. The checkers program tried to run for the first time on 30 July 1951 at NPL, but was unsuccessful due to program errors. In the summer of 1952 he successfully ran the program on

Ferranti Mark 1 The Ferranti Mark 1, also known as the Manchester Electronic Computer in its sales literature, and thus sometimes called the Manchester Ferranti, was produced by British electrical engineering firm Ferranti Ltd. It was the world's first commer ...

computer and played the first computer checkers and first video game ever. In the 1950s,

Arthur Samuel Arthur Lee Samuel (December 5, 1901 – July 29, 1990) was an American pioneer in the field of computer gaming and artificial intelligence. He popularized the term "machine learning" in 1959. The Samuel Checkers-playing Program was among the wo ...

created one of the first board game-playing programs of any kind. More recently, in 2007 scientists at the University of Alberta developed their " Chinook" program to the point where it is unbeatable. A

brute force Brute Force or brute force may refer to: Techniques * Brute force method or proof by exhaustion, a method of mathematical proof * Brute-force attack, a cryptanalytic attack * Brute-force search, a computer problem-solving technique People * Brut ...

approach that took hundreds of computers working nearly two decades was used to solve the game, showing that a game of checkers will always end in a

draw Draw, drawing, draws, or drawn may refer to: Common uses * Draw (terrain), a terrain feature formed by two parallel ridges or spurs with low ground in between them * Drawing (manufacturing), a process where metal, glass, or plastic or anything ...

if neither player makes a mistake. The solution is for the checkers variation called go-as-you-please (GAYP) checkers and not for the variation called three-move restriction checkers. As of December 2007, this makes American checkers the most complex game ever solved. In Nov 1983, the Science Museum Oklahoma (then called the Omniplex) unveiled a new exhibit: Lefty the Checker Playing Robot. Programmed by Scott M Savage, Lefty used an Armdroid robotic arm by

Colne Robotics Colne () is a market town and civil parish in the Borough of Pendle in Lancashire, England. Located northeast of Nelson, north-east of Burnley, east of Preston and west of Leeds. The town should not be confused with the unrelated Colne Va ...

and was powered by a

6502 processor The MOS Technology 6502 (typically pronounced "sixty-five-oh-two" or "six-five-oh-two") William Mensch and the moderator both pronounce the 6502 microprocessor as ''"sixty-five-oh-two"''. is an 8-bit microprocessor that was designed by a small te ...

with a combination of Basic and Assembly code to interactively play a round of checkers with visitors to the museum. Originally, the program was deliberately simple so that the average museum visitor could potentially win, but over time was improved. The improvements however proved to be more frustrating for the visitors, so the original code was reimplemented.

Computational complexity

Generalized Checkers is played on an N × N board. It is

PSPACE-hard In computational complexity theory, PSPACE is the set of all decision problems that can be solved by a Turing machine using a polynomial amount of space. Formal definition If we denote by SPACE(''t''(''n'')), the set of all problems that c ...

to determine whether a specified player has a winning strategy. And if a polynomial bound is placed on the number of moves that are allowed in between jumps (which is a reasonable generalisation of the drawing rule in standard Checkers), then the problem is in PSPACE, thus it is PSPACE-complete. However, without this bound, Checkers is EXPTIME-complete. However, other problems have only

polynomial complexity In computer science, the time complexity is the computational complexity that describes the amount of computer time it takes to run an algorithm. Time complexity is commonly estimated by counting the number of elementary operations performed by ...

: * Can one player remove all the other player's pieces in one move (by several jumps)? * Can one player king a piece in one move?

National and regional variants

File:International draughts.jpg, 10x10 board, starting position in

File:Draughts.svg, 8x8 board, starting position in

, Brazilian,

Czech draughts Czech draughts is a board game played in the territory formerly occupied by Czechoslovakia (the present day Czech Republic and Slovakia). It is governed by the Czech Draughts Federation. Game rules The draughtsboard has eight ranks and eight f ...

Pool checkers American Pool Checkers, also called "American Pool", is a variant of draughts, mainly played in the mid-Atlantic and southeastern United States and in Puerto Rico. Basic rules As in the related game English draughts English draughts (Brit ...

, and

File:Canadian Checkers gameboard and init config.PNG, 12x12 board, starting position in

Canadian draughts Canadian checkers (or Canadian draughts) is a variant of the strategy board game draughts. It is one of the largest draughts games, played on a 12×12 checkered board with 30 game pieces per player. History The game was invented by the French se ...

File:TurkishDraughts (trad).png, 8x8 board, starting position in Turkish draughts and

Armenian draughts Armenian draughts, or Tama, is a variant of draughts (or checkers) played in Armenia. The rules are similar to Dama. Armenian draughts, however, allows for diagonal movement. Rules On an 8×8 board, 16 men are lined up on each side in two ro ...

File:Damiera.JPG, 8x8 board, starting position in

Italian Italian(s) may refer to: * Anything of, from, or related to the people of Italy over the centuries ** Italians, an ethnic group or simply a citizen of the Italian Republic or Italian Kingdom ** Italian language, a Romance language *** Regional It ...

and Portuguese draughts File:Column draughts game.gif, 8x8 board, starting position and example play in

Bashni Bashni (Russian: ба́шни, ''towers''), also known as column draughts, multi-level checkers, and rarer Chinese checkers, is a variation of draughts, known in Russia since the 19th century. The game is played according to the basic rules of ...

Russian Column draughts

Column draughts (Russian towers), also known as

, is a kind of draughts, known in Russia since the beginning of the nineteenth century, in which the game is played according to the usual rules of Russian draughts, but with the difference that the captured man is not removed from the playing field: rather, it is placed under the capturing piece (man or tower). The resulting towers move around the board as a whole, "obeying" the upper piece. When taking a tower, only the uppermost piece is removed from it: and the resulting tower belongs to one player or the other according to the color of its new uppermost piece. Bashni has inspired the games

and Emergo.

Flying kings; men can capture backwards

Flying kings; men cannot capture backwards

No flying kings; men cannot capture backwards

Championships

* World Checkers/Draughts Championship in American checkers since 1840 * Draughts World Championship in international draughts since 1885 *

Women's World Draughts Championship The Women's Draughts World Championship is the world championship in international draughts organized by the World Draughts Federation (FMJD). The championship occurs every two years. In the even year following the tournament must take place the Wor ...

in international draughts since 1873 * Draughts-64 World Championships since 1985

Federations

World Draughts Federation The Fédération Mondiale du Jeu de Dames (FMJD, World Draughts Federation) is the international body uniting national draughts federations. It was founded in 1947 by four Federations: France, the Netherlands, Belgium and Switzerland. Members C ...

(FMJD) was founded in 1947 by four Federations: France, the Netherlands, Belgium and Switzerland. * International Draughts Federation (IDF) was established in 2012 in Bulgaria.

Games sometimes confused with checkers variants

Halma Halma (from the Greek word ἅλμα meaning "jump") is a strategy board game invented in 1883 or 1884 by George Howard Monks, an American thoracic surgeon at Harvard Medical School. His inspiration was the English game ''Hoppity'' which was de ...

: A game in which pieces move in any direction and jump over any other piece, friend or enemy (but with no captures), and players try to move them all into an opposite corner. * Chinese checkers: Based on Halma, but uses a star-shaped board divided into equilateral triangles. * Kōnane: "Hawaiian checkers".

Notes

References

Citations

Sources

External links

Draughts associations and federations
American Checker Federation (ACF)American Pool Checkers Association (APCA)Danish Draughts FederationEnglish Draughts Association (EDA)European Draughts Confederation

Northwest Draughts Federation (NWDF)Polish Draughts Federation (PDF)Surinam Draughts Federation (SDB)World Checkers & Draughts Federation

World Draughts Federation (FMJD)The International Draughts Committee of the Disabled (IDCD)
History, articles, variants, rules
A Guide to Checkers Families and Rules by Sultan RatroutCheckers MavenCheckersUSA
checkers books, electronic editions
Alemanni Checkers PagesOn the evolution of Draughts variants
{{Authority control Abstract strategy games Traditional board games Individual sports