⟦7c50e81fc⟧

TextFile

.TH CCHESS 6 12/26/84
.UC 4
.SH NAME
cchess \- Correspondence Chess Game
.SH SYNOPSIS
.B cchess
[
.B \-a
]
[
[
.B \-t
]
[
.B \-b
]
.B player1
[
.B player2
]
]
[
.B \-s
]
[
.B \-g
[
.B player
]
]
.SH DESCRIPTION
.I  Cchess
is a correspondence chess game moderator.
It allows players on a Unix system to challenge each other to chess games,
with notification of moves sent by mail.
It does not allow for play across uucp-type networks.
.PP
To challenge another user, or to continue a game already begun,
.I cchess
should be run with a single argument:  the userid of the other player.
To experiment, you may challenge yourself to a game of chess.
Note that in this case, no notification of moves is sent by mail.
If run with two userid as arguments,
.I cchess
will allow you to view a game between the two players named, if the game
is not a private one.
.PP
The command line options are:
.TP
.B \-s
Print a scoreboard showing the outcome of all games completed on the system.
.TP
.B \-g
Print a list of all games currently in progress on the system.  If a user
id is given after the -g option, only games involving that player are
printed.
.TP
.B \-a
If no player names are given with the -a flag, cchess finds all games in
which it is your turn to move, and runs the program on each one.  If one
player name is given, it gives you a chance to view all non-private
games involving the named player.
.TP
.B \-b
Display chessboards in a larger format with highlighted pieces.
A terminal with 24 lines and 80 columns is just adequate for standard chess.
If you are playing the Courier variant game, you need 90 columns.
If your screen is plainly too small, this option will be ignored.
.TP
.B \-t
Print a transcript of a game between the user and one named player, or
between two other users, if two names are given.  Transcripts
of private games cannot be printed, unless the user is one of the players.
This may be used with the -a flag.
.PP
When you make a challenge, you will be asked to choose from several options.
You can choose which color you want, whether you want the game to be private,
and whether you want to play a variant game.
A large number of variant games are supported, and it is possible to combine
the various standard variants to create entirely new games.
The standard variants will be described below.
.PP
You may also choose if you want computer kibitzing.
This option is intended as a compensation for the poor board graphics.
It causes the computer to warn you
if it looks like you might be throwing a piece away.
However, the algorithm is deliberately stupid -- 
it will overlook anything that is even vaguely subtle.
It doesn't know about checks or look ahead more than one move,
much less appreciate the potential of a sacrifice.
I recommend its use, since the only kind of mistakes it catches are those
of such incredible stupidity that they tend to spoil the game for both
players.
.PP
The person you have challenged will receive a message in the mail telling
him he has been challenged, and describing how to respond to the challenge.
He does this by running
.I cchess
with your login name as an argument.  He will be given the choice of
accepting your challenge, counter-challenging you (with different options),
or rejecting your challenge.  If he accepts and is white, he will be asked
for his opening move.  In any case, you will be notified of the result by
mail.
.PP
When moving you will be shown a (rather crude) representation of the
board, and will be asked if you wish to move, forfeit, propose a draw,
or watch a playback of the last few positions.  Moves are entered in a
modified algebraic notation (e.g. "E2-E4" for a king pawn opening).  To
castle, move the king two spaces to his left or right.  En passaunt 
and pawn promotion are fully supported.  You
will be given one chance to take back your move before it is saved.
Also, you can attach a short comment to each move.
This will be displayed for the other player along with your move.
.PP
Some of the legal commands are given in the prompt,
but there are a several others that may be issued.
"H" can be entered to ask for help,
"Q" can be entered to quit,
or "^L" can be entered to redraw the screen.
Unfortunately, these don't work everywhere.
Also "V" prints the current
.I cchess
version number, "O" prints the
current game options.
Finally, the "C" command may be used to propose that the game be cancelled
(that is ended without recording a win for either player).
The other player will have to agree to this before it takes affect.
.PP
.I Cchess
will detect checks, checkmates and stalemates in which a player cannot move.
If a position is repeated for the third time, or if fifty moves elapse
without a pawn move or a capture, players have the option of declaring the
game a draw unilaterally.
Perpetual check is not detected.
When a game is over, both players will be given a chance to see a playback
and save a transcript of the game.
.PP
.I Cchess
looks in the file
.I /etc/termcap
to determine terminal characteristics,
but does not really need a smart terminal.  It is designed to be
runnable on virtually any terminal including hard copy terminals
(extremely small displays could be a problem), while still taking
maximum advantage of the capabilities which are available.
If the TERM variable is not set, it assumes you have a 40 column dumb terminal.
.PP
If the "ccreap" program has been installed, it will send mail to remind
people to move in games if they haven't moved for a while.
It will eventually delete games that appear to have been abandoned.
.PP
The variant games supported by
.I cchess
are listed below:
.SH KRIEGSPIEL
.PP
Kriegspiel was invented by W. H. Temple sometime around 1900.
In the Kriegspiel variant game, you will not be shown the other player's
pieces, nor will you be told his moves.
You will only be told if the moves you try are legal.
Once you propose a legal move, you cannot take the move back.
You will be told when you take a piece, and your opponent
will be told how many illegal moves you tried before finding a legal move.
Note that in Kriegspiel once you propose a move,
you will not be allowed to exit the program until you make a legal one.
The current implementation of Kriegspiel gets some of the rules wrong.
One of these days I'll correct this.
.SH SHATRANJ
.PP
The Shatranj variant game is one of the oldest known versions of chess.
It originated in Persia around the 6th century AD, and
is almost identical to chaturanga, an older Hindi game.
It is the version of chess first introduced in Europe around the 10th century
where it prevailed until the 15th century.
It plays slower than modern chess, and has more of the tone of a wargame.
.PP
The board is the same as the modern board, but is not checkered.
The pieces are given their Persian names,
but only two are actually different from the modern pieces.
Replacing the queen, there is a much weaker piece called the minister
(firz).
The minister can move one square along any of the four diagonals.
Instead of bishops, there are elephants (fil) which move exactly
two squares along any diagonal, and can jump over any piece on the
intervening square.
In addition, the rules which allow
pawns (baidaq) to move two squares on their first move,
and the king (shah) to castle with a rook (ruhk) were not yet introduced.
A stalemate is counted a win for the player who can not move.
If a player loses all his forces except his king (shah),
he loses the game, even if his opponent lacks mating material.
Cchess adopts the common practice of allowing players to move ten
pieces on their first turn, with the restriction that no piece may
cross the centerline of the board.  The position reached by these opening
moves is called the Ta'biyat.
.SH COURIER
.PP
Courier is a 13th century European development of shatranj.
It is played on a oversized chess board having 12 columns and 8 rows.
Each player has 12 pawns and 12 miscellaneous major pieces.
To minimize confusion,
the names of many of the pieces have been altered in this implementation.
The pawn, rook, knight, and king move like their counterparts in both
shatranj and modern chess.  The elephant and minister move exactly
as in shatranj.  There are also two bishops, which are
the "couriers" after whom the game is named.
Furthermore, there is a duke (or sneak) which can move one
square forward, backward, left or right, and there is a jester (or man)
who moves exactly like a king, but, unlike the king, has no special value.
Neither castling, nor double moves for pawns are allowed, these being
recent innovations.
Stalemates and the loss of forces are treated as in shatranj.
Each player is allowed to move 12 pieces on his first turn.
.PP
Actually, several references describe various other peculiar rules
which cchess does not support.
For example,
instead of allowing multiple moves on the first turn,
the minister, the minister pawn and both rook pawns were sometimes
allowed to leap two space forward on the first move.
Pawn promotion may have required the pawn to move back to it's starting
rank two squares at a time before being promoted.
.SH RIFLE CHESS
.PP
This modern variant was devised by W. J. Seabrook in 1921.
When a capture is made, the captured piece is removed,
but the capturing piece remains on its original square, having,
in affect, shot the enemy from afar.
Otherwise, play is as usual.
.SH KAMIKAZI CHESS
.PP
This variant game was devised by Pierre Monreal in 1965.
When a capture is made, both pieces capturing and captured piece are removed.
The king is not allowed to make captures, even to escape mate.
Possibly, the king should be allowed to capture with impunity;
my source didn't specify this.
.SH KARMA CHESS
.PP
This variant game arose entirely from the author's fevered imagination.
It is played exactly as regular chess, except that when a piece captures
another, it is transformed to a piece of the same rank as the captured piece.
For example, if a black pawn should succeed in capturing a white queen,
it is immediately reincarnated as a black queen.
On the other hand, if a queen should stoop so low as to slay a pawn,
she will immediately be demoted to a pawn.
This holds for all pieces except, of course, the King, who, as the
Embodiment of the Law, may take any piece without loss of rank.
The dynamics of attack and defense are very different in Karma
Chess.  In fact, the computer kibitzer is badly confused by Karma
Chess, and is therefore not available.
.SH CONVERSION CHESS
.PP
This variant was invented and originally implemented in cchess by
Kenneth Larimer.  It is played like regular chess, but when a piece
captures it remains in it's original square, and the attacked piece
is converted to the attacker's color.  However, if the converted piece
is attacked again by the other player in the next turn it is destroyed
as in rifle chess.  It may thus be considered a combination of rifle
and karma chess.  It seems to play quite well.
.SH HALFBOARD CHESS
.PP
Halfboard chess is played on a 4 by 8 board, with each player having only
a king, a bishop, a knight, a rook, and four pawns.  It normally leads to
a shorter game than standard chess.
.SH DOUBLE CHESS
.PP
In double chess (or Marselles) each player makes two moves in each turn.
Players may not impose check until the last move of the turn, nor must a
player's king be moved out of check until his last move.  Checkmate and
stalemate detection don't work in double chess.  If you're checkmated,
forfiet.
.SH STEAMROLLER
.PP
In the Steamroller variant, Black's pieces are as in normal chess, but White
has only a king and his four center pawns.  As compensation, white may move
twice in each turn.  White may not apply check until his second move.  It
is legal for white to be in check at the end of his first move.
. I Cchess
will not annouce checkmate or stalemate against the white player.  It is
up to the white player to forfiet if he is checkmated or stalemated.
I understand white has the advantage in this variant.
.SH PROGRESSIVE CHESS
.PP
In Progressive chess, the White moves once on his first move, then Black
moves twice, then White moves three times, then Black moves four times,
and so on, with each player making one more move than the last player did.
As in double chess and steamroller, check may not be applied till the
last move of a players turn.  I've never found a really satisfactory way to
set up the mating rules.  Allowing the king to move through check makes it
impossible to checkmate him before very many moves.  Not allowing him to
move through check makes it too easy to mate him (I think there might be
a sure win for one player in this version).  Currently the default rule is
that the king is just a normal piece, and you must capture all enemy pieces
to win.  Games seem to be quite short.
.SH MAHARAJAH
.PP
In Maharajah (a.k.a. Maharajah and the Savoys),
white has only one piece: a maharajah.  The maharajah can
move along ranks, files and diagonals like a queen plus it can jump like
a knight.  Black has the normal complement of chess pieces.  It seems that
this game can normally be won by the black player, if he is sufficiently
careful.
.SH LOSING CHESS
.PP
In losing chess, the winner is the player who first gets stalemated or
loses all his pieces. 
If a player can make a capture, he is required to do so.
There are no checks or checkmates.
The king is treated just like any other piece.
.SH MIXED GAMES
.PP
The above games are actually just standard combinations of a wide variety
of low-level game options.  It is possible to brew up games of your own by
combining these options in new ways, and by editting the initial set up
of the board.  The board editor has a 'H' help command that should be clear
enough.
Most of the low-level options are easily understood if you are familiar with
the variant games above.  Cchess makes some attempt to suppress combinations
that will confuse it badly, but it's not really thorough about it.  A few
notes are in order.
.PP
Each player can have a "mateable piece" defined.  This is normally the king,
but in the Maharajah variant, the white mateable piece is the Maharajah.
A player is considered to be in check if his mateable piece is being attacked.
In some variants, there are no mateable pieces (e.g. Hexapawn and Losing
Games).  The board editor insists that each player who has a mateable piece
defined have exactly one on the board.  Another option allows the capture
rules to be selected.  These may be different for normal pieces and mateable
pieces.  If multiple moves are allowed, you must specify whether the
mateable pieces may move through check (they may never be left in check
after the players last move).  If they are allowed to move through check,
the automatic checkmate detection code will not operate.  Regardless of
what your mateable piece is, only kings & rooks can castle.  Even if you
allow castling, it will only work if there is rook on the edge of the
board in the same row as a king.  If you have multiple kings, only one
is allowed to castle in the course of a game.  Jesters differ from kings
only in that they can't castle.  There are three options for pawn promotion.
The option that normally allows promotion to either a Queen, a Rook, a Knight
or a Bishop, also allows promotion to a King.
It is, however, never legal to promote to a mateable piece.
The option that disallows promotion is automatically used if the pawn is
a mateable piece.
.SH BUGS
.PP
The board is hard to see at first
because of the limited graphics capability.
It may help to set up a real board to figure out your moves on.
.I Cchess
won't work over intersystem mail, because all transcripts
are kept in a local game file.
The rules for variant games are disputable.
Pawn promotion is not announced for kriegspiel players.
The scoreboard should be sorted in some intelligent order.
Beyond this, the wide variety of options which can be combined in Mixed
Games undoubtedly lead to more bugs than the author cares to think about.
.PP
Also note that while
.I cchess
will work with just about any terminal, it is
more picky than many other programs about the strict correctness of the
termcap.  For example, if neither the "bs" nor the "bc" field is defined
in the termcap,
.I cchess
will refuse to backspace.
.PP
It is also hard to tell if your opponent is using a chess program to generate
his moves.  This is one of the advantages of playing variant games.
.SH AUTHOR
Jan Wolter (janc@crim.eecs.umich.edu)
.SH FILES
.DT
/etc/termcap	Terminal data base.
.br
/usr/games/lib/chessboards	Directory for games in progress.
.br
/usr/games/lib/chessboards/gamelist	Record of past games.
DataMuseum.dk

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