The rules of chess have evolved quite a bit over the centuries. The basic move of the king, rook, and knight are unchanged. Pawns originally did not have the option of moving two squares on their first move and did not promote to another piece if they reached their eighth rank. The queen was originally the fers, which could move one square diagonally in any direction or leap two squares diagonally, forwards, or to the left or right on its first move. The bishop was originally an alfil, which could leap two squares along any diagonal. The first group of changes to the rules changed the movements of the bishop and queen to their modern versions.
A second group of laws emerged in the Middle Ages. The king and rook acquired the right to castle. (See Castling and Variations throughout history for different versions of the rule.) Pawns gained the option of moving two squares on their first move, and the en passant rule was a natural consequence of that new option. Pawns also gained the ability to be promoted to a higher piece if they reached their eighth rank.
Three other new rules were introduced, each of which have changed through the years:
The stalemate rule was added, and the outcome has changed several times. The threefold repetition rule was added, although at some times up to six repetitions have been required, and other conditions have been firmed up. The fifty move rule under which a draw can be claimed if there has been no pawn move and no capture in the last fifty moves. At various times, the number of moves required was different, such as twenty-four, sixty, seventy, or seventy-five. For several years in the 20th century, the standard fifty moves was extended to one hundred moves for a few specific endgames. A third group of new laws included the touch-move rule and the accompanying "j'adoube/adjust" rule. Other laws in this group are that White moves first; the orientation of the board; the procedure if an illegal move was made; the procedure if the king had been left in check for some moves; and issues regarding the behavior of players and spectators. The Staunton chess set was introduced in 1849 and it became the standard style of pieces. The size of pieces and squares of the board was standardized (Hooper & Whyld 1992).
The first known publication of chess rules was in a book by Luis Ramirez de Lucena about 1497, shortly after the movement of the queen, bishop, and pawn were changed to their modern form (Just & Burg 2003). In the 16th and 17th centuries there were big differences of opinion concerning rules such as castling, pawn promotion, stalemate, and en passant. Some of these differences existed until the 19th century (Harkness 1967:3).
As chess clubs arose and tournaments became common, there was a need to formalize the rules. The 18th century player François-André Danican Philidor wrote a set of rules that were widely used, as well as rules by later writers Jacob Sarratt and George Walker. In the 19th century, many major clubs published their own rules, e.g. The Hague in 1803, London in 1807, Paris in 1836, and St. Petersburg in 1854. In 1851 Howard Staunton called for a "Constituent Assembly for Remodeling the Laws of Chess" and proposals by Tassilo von Heydebrand und der Lasa were published in 1854. Staunton had published rules in Chess Player's Handbook in 1847 and his new proposals were published in 1860 in Chess Praxis; they were generally accepted in English-speaking countries. German-speaking countries usually used the writings of chess authority Johann Berger or Handbuch des Schachspiels by Paul Rudolf von Bilguer, first published in 1843.
In 1924 the Fédération Internationale des Échecs (FIDE) was formed, and in 1929 it took up the task of standardizing the rules. At first FIDE tried to establish a universal set of rules, but translations to different languages differed slightly. Although FIDE rules were used for international competition under their control, some countries continued to use their own rules internally. FIDE issued new editions of the rules every few years (1929, 1952, 1955, 1966, 1974, 1992, etc.), with amendments in some other years. In 1984 FIDE abandoned the idea of a universal set of laws, although FIDE rules are the standard for high-level play (Hooper & Whyld 1992). The rules of national FIDE affiliates (such as the United States Chess Federation, or USCF) are based on the FIDE rules, with slight variations (Just & Burg 2003). Kenneth Harkness published popular rulebooks in the United States starting in 1956, and the USCF continues to publish rulebooks for use in USCF
The tradition of organized competitive chess started in the sixteenth century and has developed extensively. Chess today is a recognized sport of the International Olympic Committee. The first official World Chess Champion, Wilhelm Steinitz, claimed his title in 1886; Viswanathan Anand is the current World Champion (2008). Theoreticians have developed extensive chess strategies and tactics since the game's inception. Aspects of art are found in chess composition. One of the goals of early computer scientists was to create a chess-playing machine, and today's chess is deeply influenced by the abilities of current chess programs and by the possibility to play online. In 1996, a match between Garry Kasparov, then World Champion, and a computer proved for the first time that machines are able to beat even the strongest human players.