Monster Media 1993 #2/Image.iso/games2/telego41.zip/GORULES.TXT

Text File | 1992-01-31 | 16KB | 289 lines

There are several sets of rules for playing Go.  The ones below were adopted
for a three year trial period by the American Go Association (AGA) at the
1991 National Board meeting.

Note: Telego counts the score using the 'Territory' method described below.
      Since 'Area' counting is not used, the easiest way to use Telego is to
      modify the Official Rules (the outcome of the game will not be
      affected) in two areas:
             1) White is not required to make the last move.
             2) 'Pass stones' are not required.
      Any compensation (see below) is NOT computed by Telego.

*****************************************************************************

AGA Rules Committee                                       September 1, 1991

                           Official AGA Rules of Go

*   The following are the American Go Association Rules of Go for amateur
*  play.  Unless specifically stated otherwise, these rules are in effect
*  at all AGA sanctioned events.  Organizers and tournament directors are
*  free to specify other sets of rules for use in their events.  Each line
*  of the comments to the rules starts with an asterisk.

   Any paraphrase of these rules which is identical in content is acceptable
as a statement of the AGA Rules of Go so long as it makes reference to the
more complete Official rules given below.

*   By "identical in content" we mean that the result of applying these
*  paraphrased rules should give the same result as would the Official Rules
*  in every situation.}
*
*   These rules are supplemented by the Official AGA Tournament Regulations
*  governing time control, player conduct, role of monitors, etc.

   1) The Board and Stones: Go is a game of strategy between two sides
usually played on a 19x19 grid (the board).  The game may also be played on
smaller boards, 13x13 and 9x9 being the two most common variants.  The board
is initially empty unless a handicap is given (see Rule 4).  The two sides,
known as BLACK and WHITE, are each provided with an adequate supply of
playing tokens, known as STONES, of the appropriate color.

*   For recording purposes, the horizontal lines of the board are designated
*  1,2,3,...,19, starting from the bottom as seen by Black.  The vertical
*  lines are designated A,B,C,...T (skipping 'I'), starting from the left as
*  seen by Black.  Points on the board are identified by their coordinates,
*  e.g. A-1, C-3, T-19, etc.

   2) Play: The players alternate in moving, with Black playing first.  In
handicap games, White plays first after Black has placed his or her handicap
stones.  A MOVE consists in playing a stone of one's color on an empty
intersection (including edges and corners), or in PASSING.  Certain moves
are ILLEGAL (Rules 5 and 6), but a pass is always legal (Rule 7).  POINTS
are awarded for controlling space in a manner described below (Rule 12).  The
object of the game is to end with the greater total number of points.

  3) Compensation: In an even (non-handicap) game, Black gives White a
compensation of 5.5 points for the advantage of the first move.  This
compensation is added to White's score at the end of the game.  In handicap
games Black gives White 0.5 point compensation.  This avoids draws.

   4) Handicaps: The game may be played with a HANDICAP to compensate for
differences in player strengths.  The weaker player takes Black, and either
moves first, giving only 0.5 point compensation to White, as in Rule 3 (this
is known as a "one stone handicap"), or places 2 to 9 stones on the board
before the first White move.

*   The nine intersections corresponding to the horizontal lines 4, 10, and
*  16 and the vertical lines D, K, and Q are called STAR POINTS and are
*  ordered as follows:
*             1st star point   Q-16     5th star point  Q-10
*             2nd star point   D-4      6th star point  D-10
*             3rd star point   Q-4      7th star point  K-16
*             4th star point   D-16     8th star point  K-4
*                   9th star point   K-10 (center point)
*   The handicap stones are traditionally played as follows:
*       2 stones -- on the 1st and 2nd star points
*       3 stones -- on the 1st through 3rd star points
*       4 stones -- on the 1st through 4th star points
*       5 stones -- on the 1st through 4th star points and the center point
*       6 stones -- on the 1st through 6th star points
*       7 stones -- on the 1st through 6th star points and the center point
*       8 stones -- on the 1st through 8th star points
*       9 stones -- on the 1st through 9th star points
*   Unless otherwise specified, handicap stones shall be placed in this
*  fashion.  Handicaps greater than nine stones and handicaps on boards with
*  fewer than 19 lines are not standardized.

   If the players have agreed to use area counting to score the game (Rule
12), White receives an additional point of compensation for each Black
handicap stone after the first.

*   Black would otherwise gain an additional point of area for each handicap
*  stone.

   5) Capture: Stones of the same color are said to be CONNECTED if they
are adjacent along horizontal or vertical -- not diagonal -- lines on the
board.  A STRING of connected stones consists of those stones which can be
reached from a given stone by moving only to adjacent stones of the same
color.  A string of connected stones is SURROUNDED by stones of the
opposite color if it has no empty points horizontally or vertically -- NOT
DIAGONALLY -- adjacent to any of its member stones.  (Such adjacent empty
points are known as LIBERTIES of the string.)

   After a player moves, any stone or string of stones belonging to the
opponent which is completely surrounded by the player's own stones is
CAPTURED, and removed from the board.  Such stones become PRISONERS of the
capturing player.  It is ILLEGAL for a player to move so as to create a
string of his or her own stones which is completely surrounded (without
liberties) after any surrounded opposing stones are captured.

*   This means that it is possible to fill an empty space within an
*  opponent's group and capture even if the player's own stone or stones
*  would momentarily be surrounded by the group being captured. See Figure 2.
*  But SELF-CAPTURE IS ILLEGAL.

   6) Repeated Board Position (Ko): It is ILLEGAL to play in such a way as to
recreate a previous board position from the game, with the same player to
play.

*   The most typical example is a situation where the players can each
*  alternately capture and recapture a single stone.  This is known as "ko"
*  (See figure 3).  After the first capture the player moving next may NOT
*  capture immediately, as this would repeat the board position; instead,
*  that player must play somewhere else on the board (or pass).  The player
*  who first captured may then "fill" the ko (or otherwise resolve it), or
*  play elsewhere as well (often in response to the other player's previous
*  move.) If the board position has changed, and the ko has not yet been
*  resolved, the opponent is then free to capture, and it is the original
*  player who may not then immediately recapture.  This process is known as a
*  KO FIGHT, and the moves played away from the ko itself are known as KO
*  THREATS.
*
*   Rarely, multiple kos or other repetitive situations will arise; the
*  principle for handling them is always the same: the players must avoid
*  repeating the full-board position, so they are periodically, and
*  alternately, forced to play away from the repetitive situation before
*  responding.

   7) Passing: On his or her turn, a player may PASS by handing the opponent
a stone, referred to as a PASS STONE, rather than playing a stone on the
board.

*   Normally neither player would choose to pass if there were any worthwhile
*  moves to be made on the board (even if they did not have to give up a pass
*  stone).  Thus, the exchange of a pass stone with the opponent also serves
*  as a signal that the player passing believes that the game is over.  Of
*  course, the opponent is free to continue to play if he or she believes
*  that there are worthwhile moves left to make, and the player who passed is
*  free to respond.

   8) Illegal Moves:  An illegal move is one violating the rules.  If a
player makes an illegal move -- such as moving twice in a row (i.e., before
the opponent has made a response), attempting to play on an occupied
intersection, self-capture, or retaking a ko so as to repeat the full board
position, the player must take back his or her move (BOTH moves, if he or she
moved twice in succession), it shall be treated as a PASS, and a pass stone
exchanged.

   An illegal move must be noted as such by the opponent before he or she
makes his or her move.  When a player moves, he or she is tacitly accepting
the opponent's previous move as valid.  In particular, if it is discovered
that an earlier move by one of the players was illegal, the game must
nevertheless be continued AS IT STANDS unless both players agree to restore
the earlier board position and proceed from that point.

   9) Ending the Game: Two consecutive passes signal the end of the game.
After two passes, the players must attempt to agree on the status of all
groups of stones remaining on the board.  Any stones which the players agree
could not escape capture if the game continued, but which have not yet been
captured and removed, are termed DEAD STONES.  If the players agree on the
status of all such groups, they are removed from the board as prisoners of
the player who could capture, and the game is scored as in Rule 12.  If there
is a disagreement over the status of some group or groups, PLAY IS RESUMED as
specified in Rule 10.

   10) Disputes: If the players disagree about the status of a group of
stones left on the board after both have passed, PLAY IS RESUMED, with the
opponent of the last player to pass having the move.  The game is over when
the players agree on the status of all groups on the board, or, failing such
agreement, if both players pass TWICE in succession.  In this case ANY STONES
REMAINING ON THE BOARD ARE DEEMED ALIVE.  Any stone or group of stones
surrounded and captured during this process is added to the capturing
player's prisoners as usual.

*   It is recommended, particularly if the players do not share a common
*  language, that the following procedure be used to determine agreement on
*  the status of groups.  After two consecutive passes, the next player
*  touches each connected string of opposing stones on the board which he or
*  she believes to be dead.  If the opponent disagrees, he or she also
*  touches the same string. When a player is done indicating groups he or she
*  believes are dead, he or she PASSES, passing a stone to the opponent as
*  usual, and the opponent follows the same procedure.  AT ANY POINT, A
*  PLAYER MAY RESUME PLAY RATHER THAN CONTINUING TO INDICATE DEAD GROUPS OR
*  PASSING. If BOTH players pass and there is no disagreement indicated, the
*  game is over, and all groups which the players have indicated as dead are
*  removed from the board. If they both pass while a disagreement still
*  exists, ALL STONES REMAINING ON THE BOARD ARE ALIVE, and the board is
*  counted as it stands. (The burden is thus effectively on the player who
*  would be disadvantaged by such a result to resume play in the event of a
*  disagreement.)

   11) The Last Move: White must make the last move -- if necessary, an
additional pass, with a stone passed to the opponent as usual.  The total
number of stones played or passed by the two players during the entire game
must be equal.

   12) Counting: There are two methods for counting the score at the end of
the game.  One is based on TERRITORY, the other on AREA.  The players should
agree in advance of play which method they will use.  If there is no
agreement, territory counting shall be used.

*   Although players' scores may differ under the two methods, the
*  difference in their scores, and hence the game result, will be the same.

   Territory: Those empty points on the board which are entirely surrounded
by live stones of a single color are considered the TERRITORY of the player
of that color.

*   At the end of the game, the empty points remaining on the board fall
*  into REGIONS.  A region is the smallest set of empty points containing a
*  given empty point and any empty points adjacent to any empty point in the
*  set.  That is, a region consists of those empty points which can be
*  reached from a given empty point by moving only to adjacent empty points.
*  A region is entirely surrounded by stones of a single color if the only
*  stones adjacent to empty points in the region are of that color.  There
*  are situations (Japanese SEKI) in which a region of empty points is left
*  at the end of a game which is NOT entirely surrounded by stones of a
*  single color, and which neither player would fill because to do so would
*  bring dire consequences.  See Figure 4.  When counting by territory, it is
*  possible that there will be some neutral points left between live groups
*  belonging to the two players which have not been filled, although it is
*  customary to fill all such points before scoring the game.

   Area: All live stones of a player's color left on the board together with
as many points of territory surrounded by a player constitute that player's
AREA.

   Neutral Points: Any empty points left on the board at the end of the game
which are NOT completely surrounded by either player's stones are known as
NEUTRAL POINTS, and are not counted toward either player's territory or
area. (There will rarely be any such points.)

   Counting by Territory: When counting by territory, players add up their
total territory LESS any prisoners held by the opponent (including dead
stones removed at the end of the game).  The player with the greater total
(after adjusting for any compensation offered according to Rule 3) is the
winner.

*   It is customary for the players to fill in their opponent's territory
*  with their prisoners, and to then rearrange their territories to
*  facilitate counting.  These are merely mechanical conventions to simplify
*  counting.

   Counting by Area: When counting by area, the players add up their total
area.  PRISONERS ARE IGNORED.  The player with the greater total area
(after adjusting for any compensation offered according to Rules 3 and 4) is
the winner.

*   In fact, since the total of the two players' areas will sum to 361,
*  less any neutral points left on the board in seki, it is generally only
*  necessary for ONE of the two players to count their area; if it exceeds
*  180, (or 180 adjusted for half of any neutral points in seki), they are
*  the winner.  It is customary for the player doing the counting according
*  to this method to fill in his or her territory and then rearrange the
*  stones into convenient heaps.  Again, these are merely mechanical
*  conventions to simplify the counting process.


*  In the Figures:  O = White
*                   X = Black
*                   + = intersection
*                   - = edge intersection

  +++++++++            ++++++++       +++++++++
  ++OOOOO++            ++++++++       +++++++++
  ++OXXXO++            ++++++++       +++++++++
  ++OX*XO++            +++XO+++       ++OOOXX++
  ++OXXXO++            ++X+XO++       ++OXXOX++
  ++OOOOO++            +++XO+++       ++OX+OX++
  +++++++++            ++++++++       --OX-OX--

  Figure 2             Figure 3       Figure 4
  White * captures        Ko            Seki
  the Black stones