question: How can changes in rules of chess in the 10th-15th century be accepted by people, when it has no governing body to consider the new rule as official?
comment: Because people can accept things without some organization or "governing body" telling them to accept it. They use their reasoning capabilities to evaluate it themselves and make an individual choice. Usually, if enough people independently agree on a rule change, and it reaches a tipping point, people who don't accept the change will be forced into a position where they either accept it begrudgingly or find themselves with no one else to play with. In many, many, cases, there usually isn't a consensus and you end up with two different games or at least a game with lots of different variations.
passages: In 2008, FIDE added the variant Chess960 to the appendix of the "Laws of Chess". Chess960 uses a random initial set-up of main pieces, with the conditions that the king is placed somewhere between the two rooks, and bishops on opposite-color squares. The castling rules are extended to cover all these positions.
  
  In the 21st century, rules about such things as mobile phones and unauthorised use of chess engines were introduced.
  
  Section::::Variations.
   A Barrister, Temple.—Calls our attention to the ridiculous alteration of the Laws of Chess, by G. Walker, in his "New Treatise on Chess", and asks, "Is it possible such absurdities are sanctioned by the London Chess Club?" The only sanction give to Walker's puerilities by the Committee is to laugh at them. His books on Chess are no authority except among the lowest class of players.
   In 1924, 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 various languages differed slightly. Although FIDE rules were used for international competition under their control, some countries continued to use their own rules internally . In 1952 FIDE created the Permanent Commission for the Rules of Chess (also known as the Rules Commission) and published a new edition of the rules. The third official edition of the laws was published in 1966. The first three editions of the rules were published in French, with that as the official version. In 1974 FIDE published the English version of the rules (which was based on an authorized 1955 translation). With that edition, English became the official language of the rules. Another edition was published in 1979. Throughout this time, ambiguities in the laws were handled by frequent interpretations that the Rules Commission published as supplements and amendments. In 1982 the Rules Commission rewrote the laws to incorporate the interpretations and amendments . In 1984 FIDE abandoned the idea of a universal set of laws, although FIDE rules are the standard for high-level play . With the 1984 edition, FIDE implemented a four-year moratorium between changes to the rules. Other editions were issued in 1988 and 1992 , .
   Between 1475 and 1500 the queen and the bishop also acquired their current moves, which made them much stronger pieces . When all of these changes were accepted the game was in essentially its modern form .
   In formal competition, each player is obliged to record each move as it is played in a chess notation in order to settle disputes about illegal positions, overstepping time control, and making claims of draws by the fifty-move rule or repetition of position. Algebraic chess notation is the accepted standard for recording games today. There are other systems such as ICCF numeric notation for international correspondence chess and the obsolete descriptive chess notation. The current rule is that a move must be made on the board before it is written on paper or recorded with an electronic device.
   This updating procedure is at the core of the ratings used by FIDE, USCF, Yahoo! Games, the Internet Chess Club (ICC) and the Free Internet Chess Server (FICS). However, each organization has taken a different route to deal with the uncertainty inherent in the ratings, particularly the ratings of newcomers, and to deal with the problem of ratings inflation/deflation. New players are assigned provisional ratings, which are adjusted more drastically than established ratings.
  
  The principles used in these rating systems can be used for rating other competitions—for instance, international football matches.
   The rules of chess (also known as the laws of chess) are rules governing the play of the game of chess. While the exact origins of chess are unclear, modern rules first took form during the Middle Ages. The rules continued to be slightly modified until the early 19th century, when they reached essentially their current form. The rules also varied somewhat from place to place. Today, the standard rules are set by FIDE ("Fédération Internationale des Échecs"), the international governing body for chess. Slight modifications are made by some national organizations for their own purposes. There are variations of the rules for fast chess, correspondence chess, online chess, and Chess960.
   Demand for rules that are responsive to increasingly rapid changes has led to the suggestion that there can be, in appropriate circumstances, such a concept as "instant custom". Even within traditional doctrine, the ICJ has recognized that passage of a short period of time is not necessarily a bar to the formation of a new rule. Because of this, the question is sometimes raised as to whether the word "custom" is suitable to a process that could occur with great rapidity.
  
  Section::::International custom.:Practice by international organizations.
   There have been no recent changes to the moves of the pieces, but the wording of some rules were changed. Publicity (e.g. by chess problem setters) showed that the old wording of two rules allowed unintended types of moves:
  
  BULLET::::- The promotion rule was found to say that a pawn is to be promoted to "a piece" of unspecified colour, thus including an enemy piece (thus on occasion blocking the enemy king in, or preventing stalemate by giving the opponent something to move).
   As chess clubs arose and tournaments became common, there was a need to formalize the rules. In 1749 Philidor (1726–1795) wrote a set of rules that were widely used, as well as rules by later writers such as the 1828 rules by Jacob Sarratt (1772–1819) and rules by George Walker (1803–1879). In the 19th century, many major clubs published their own rules, including The Hague in 1803, London in 1807, Paris in 1836, and St. Petersburg in 1854. In 1851 Howard Staunton (1810–1874) called for a "Constituent Assembly for Remodeling the Laws of Chess" and proposals by Tassilo von Heydebrand und der Lasa (1818–1889) 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 (1845–1933) or "Handbuch des Schachspiels" by Paul Rudolf von Bilguer (1815–1840), first published in 1843.
   The rules of national FIDE affiliates (such as the United States Chess Federation, or USCF) are based on the FIDE rules, with slight variations . Kenneth Harkness published popular rulebooks in the United States starting in 1956, and the USCF continues to publish rulebooks for use in tournaments it sanctions.
   From 2001 to 2014, the Commission for the Revision of the Rules of Professional Conduct of the State Bar of California worked on a comprehensive revision of the California rules that was intended to, among other things, convert them into a heavily modified, localized version of the Model Rules. That is, the result would look like the Model Rules, but with appropriate modifications to preserve the substance of existing California rules that better reflect local laws and customs.
   Rules for competitions draw closely on original medieval texts outlining sport (i.e. non-lethal) tournament combat, such as King René's Tournament Book from 1460. Where original information is not available, or would present too great a risk to those fighting, new rules can be devised by an international team of referees, or "marshals", to be voted upon by fighters. As a young sport, rules are regularly updated in response to observations during competitions and subsequently rules of fighting may vary somewhat year-by-year.
  
  Section::::Armour.
   In 2001, the Commission for the Revision of the Rules of Professional Conduct of the State Bar of California began a comprehensive revision of the California rules that would, among other things, convert them into a localized version of the ABA Model Rules. However, the Commission's progress had been extremely slow, simply because there are so many substantive and structural differences between the California rules and the ABA models. In October 2010, the State Bar of California formally adopted the Commission's report, recommending adoption of 67 proposed changes to harmonise the California Rules of Professional Conduct with the ABA Model Rules of Professional Responsibility.
   BULLET::::- 13 December 2008 – The third Grand Prix tournament begins in Elista, Russia, with a number of changes to the playing list (see FIDE Grand Prix 2008–2010).
  
  BULLET::::- 15 December 2008 – Ilyumzhinov announces that both events will take place (the two-player Challenger Match and the eight-player Candidates Tournament), with a final decision on the structure in March 2009.
  
  BULLET::::- 16 December 2008 – The Association of Chess Professionals objects to the change, saying, ""The system of the World Championship cannot be changed once the cycle has started.""
   Section::::Capablanca's attempts to produce agreed rules.
   The first USCF rating list was published in December 1950. On that list, experts were players rated from 2100 to 2300 and masters were players rated from 2300 to 2500. However, within a few years, it was discovered that the ratings were rapidly deflating. As a result, the classifications were dropped by 100 points so that since then experts were rated between 2000 and 2200. In 1960, the USCF adopted the new Elo rating system replacing the original Harkness System. There have been continuous adjustments to that system ever since, with the primary purpose of stabilizing the rating system against the forces of inflation and deflation, so that a chess expert today will be approximately the same strength as a chess expert was 20 or 40 years ago.
   The first known publication of chess rules was in a book by Luis Ramírez de Lucena about 1497, shortly after the movement of the queen, bishop, and pawn were changed to their modern form . Ruy López de Segura gave rules of chess in his 1561 book Libro de la invencion liberal y arte del juego del axedrez . In the 16th and 17th centuries, there were local differences concerning rules such as castling, pawn promotion, stalemate, and "en passant". Some of these differences persisted until the 19th century ; for example differences in castling rules persisted in Italy until the late 19th century.
   However, the Commission's progress was very slow, simply because there are so many substantive and structural differences between the California rules and the Model Rules. The Commission finally finished nearly all the revisions in 2010 and the State Bar Board of Governors (later renamed the Board of Trustees) ratified them in July and September of that year. However, the proposed revisions could not go into effect unless and until they were also approved by the Supreme Court of California. As of 2014, 11 of 67 proposed rules had been finalized and submitted to the Court for its approval.
   By 1800 a claim under the rule could be made only in certain specified types of endgame, which varied from one set of rules to another. The move-count started when the request to implement the rule was made (instead of going back to the last capture or pawn move) and a capture or a pawn move did not reset the count. The rules used at the 1883 London tournament reset the count if there was a capture or pawn move, but still started the count when the claim to apply the rule was made instead of going back to the last capture or pawn move .
   Between 1888 and 1948 various difficulties that arose in match negotiations led players to try to define agreed rules for matches, including the frequency of matches, how much or how little say the champion had in the conditions for a title match and what the stakes and division of the purse should be. However, these attempts were unsuccessful in practise, as the same issues continued to delay or prevent challenges.
   In 1999, FIDE was recognised by the International Olympic Committee (IOC). Two years later, it introduced the IOC's anti-drugs rules to chess, as part of its campaign for chess to become part of the Olympic Games.
  
  Section::::Commercial agreement with Agon.
   The rules concerning stalemate were finalized in the early 19th century. Also in the 19th century, the convention that White moves first was established (formerly either White or Black could move first). Finally the rules around castling were standardized – variations in the castling rules had persisted in Italy until the late 19th century. The resulting standard game is sometimes referred to as "Western chess" or "international chess", particularly in Asia where other games of the chess family such as xiangqi are prevalent. Since the 19th century, the only rule changes have been technical in nature, for example establishing the correct procedure for claiming a draw by repetition.
   Section::::Controversy.:WCCC disqualification and banning.:Rejection of the ICGA decision by the CSVN.
  
  The Computer Chess Association of the Netherlands (CSVN) under Cock de Gorter chose "not to abide by their sanctions against Rybka", because the CSVN board "has the most serious doubts as to the rightfulness of ICGA's decision".
   The DSB uses a special decision procedure known as 'reverse consensus' or 'consensus against' that makes it almost certain that the Panel recommendations in a dispute will be accepted. The process requires that the recommendations of the Panel (as amended by the Appellate Body) should be adopted "unless" there is a consensus of the members against adoption. This has never happened, and because the nation 'winning' under the Panel's ruling would have to join this reverse consensus, it is difficult to conceive of how it ever could.
  