xboard - X user interface for GNU Chess, Crafty, the Internet Chess Server (ICS), and
electronic mail correspondence chess.
To run with GNU Chess: xboard [options]
To run with Crafty: xboard -fcp crafty -fd crafty's-directory [options]
To run with the ICS: xboard -ics -icshost hostname [options]
To play email chess: See cmail(6).
To run standalone: xboard -ncp [options]
To use in a pipeline: |pxboard
xboard is a graphical chessboard that can serve as a user interface to the GNU Chess and
Crafty chess engines, the Internet Chess Servers, electronic mail correspondence chess, or
your own collection of saved games.
As an interface to GNU Chess or Crafty, xboard lets you play a game against the machine,
set up arbitrary positions, force variations, or watch a game between two machines.
As an interface to Crafty, xboard also lets you interactively analyze your stored games or
set up and analyze arbitrary positions.
As an interface to the Internet Chess Server (ICS), xboard -ics lets you play against
other ICS users, observe games they are playing, or review games that have recently fin-
ished. Most of the "wild" chess variants on ICS are supported, including bughouse.
As an interface to electronic mail correspondence chess, xboard works with the cmail(6)
program. See its manual page for instructions.
You can also use xboard as a chessboard to play through games. It will read and write
game files and allow you to play through variations manually. You can use it to browse
games off the net or review games you have saved. These features are available at all
times; if you want to use them without starting a chess engine or connecting to the ICS,
you can do so with the command xboard -ncp.
To view games from a netnews reader like rn(1) or xrn(1), use the news reader's Save com-
mand and specify "|pxboard" as the save file name. This pipes the article to pxboard, a
simple shell script that saves the article to a temporary file and runs xboard in the
background. See the script itself for more information.
To move a piece, either drag it with the left mouse button, or click the left mouse button
once on the piece, then once more on the destination square. To drop a new piece on a
square (when applicable), press button 2 or 3 over the square and select from the popup
When xboard is iconized, its graphical icon is a white knight if it is White's turn to
move, a black knight if it is Black's turn. See Iconize below if you have problems get-
ting this feature to work.
MENU COMMANDS, BUTTONS, AND KEYS
All xboard commands are available on menus. The most frequently used commands also have
shortcut keys or on-screen buttons.
Reset Resets xboard and the chess engine to the beginning of a new chess game. The "r"
key is a keyboard equivalent. In Internet Chess Server mode, clears the current
state of xboard, then resynchronizes with ICS by sending a refresh command. If
you want to stop playing, observing, or examining a game on ICS, use an appropri-
ate command from the Action menu, not Reset.
Plays a game from a record file. The "g" key is a keyboard equivalent. A popup
dialog prompts you for the file name. If the file contains more than one game, a
second popup dialog displays a list of games (with information drawn from their
PGN tags, if any), and you can select the one you want. Alternatively, you can
load the Nth game in the file directly from the file name dialog, by typing the
number N after the file name, separated by a space.
The game file parser will accept PGN (portable game notation), or in fact almost
any file that contains moves in algebraic notation. Notation of the form "P@f7"
is accepted for piece-drops in bughouse games; this is a nonstandard extension to
PGN. If the file includes a PGN position (FEN tag), or an old-style xboard posi-
tion diagram bracketed by "[--" and "--]" before the first move, the game starts
from that position. Text enclosed in parentheses, square brackets, or curly
braces is assumed to be commentary and is displayed in a pop-up window. Any other
text in the file is ignored. PGN variations (enclosed in parentheses) are treated
as comments; xboard is not able to walk variation trees. The nonstandard PGN tag
[Variant "varname"] functions similarly to the -variant command-line option (see
below), allowing games in certain chess variants to be loaded. There is also a
heuristic to recognize chess variants from the Event tag, by looking for the
strings that the Internet Chess Servers put there when saving variant ("wild")
Load Next Game
Loads the next game from the last game record file you loaded. The shifted "N"
key is a keyboard equivalent.
Load Previous Game
Loads the previous game from the last game record file you loaded. The shifted
"P" key is a keyboard equivalent. Not available if the last game was loaded from
Reload Same Game
Reloads the last game you loaded. Not available if the last game was loaded from
Appends a record of the current game to a file. A popup dialog prompts you for
the file name. If the game did not begin with the standard starting position, the
game file includes the starting position used. Games are saved in the PGN (porta-
ble game notation) format, unless the oldSaveStyle option is True, in which case
they are saved in an older format that is specific to xboard. Both formats are
human-readable, and both can be read back by the Load Game command. Notation of
the form "P@f7" is generated for piece-drops in bughouse games; this is a nonstan-
dard extension to PGN.
Copies a record of the current game to an internal clipboard in PGN format and
sets the X selection to the game text. The game can be pasted to another applica-
tion (such as a text editor or another copy of xboard) using that application's
paste command. In many X applications, such as xterm and emacs, the middle mouse
button can be used for pasting; in xboard, you must use the Paste Game command.
Interprets the current X selection as a game record and loads it, as with Load
Sets up a position from a position file. A popup dialog prompts you for the file
name. If the file contains more than one saved position, and you want to load the
Nth one, type the number N after the file name, separated by a space. Position
files must be in FEN (Forsythe-Edwards notation), or in the format that the Save
Position command writes when oldSaveStyle is turned on.
Load Next Position
Loads the next position from the last position file you loaded.
Load Previous Position
Loads the previous position from the last position file you loaded. Not available
if the last position was loaded from a pipe.
Reload Same Position
Reloads the last position you loaded. Not available if the last position was
loaded from a pipe.
Appends a diagram of the current position to a file. A popup dialog prompts you
for the file name. Positions are saved in FEN (Forsythe-Edwards notation) format
unless the oldSaveStyle option is True, in which case they are saved in an older,
human-readable format that is specific to xboard. Both formats can be read back
by the Load Position command.
Copies the current position to an internal clipboard in FEN format and sets the X
selection to the position text. The position can be pasted to another application
(such as a text editor or another copy of xboard) using that application's paste
command. In many X applications, such as xterm and emacs, the middle mouse button
can be used for pasting; in xboard, you must use the Paste Position command.
Interprets the current X selection as a FEN position and loads it, as with Load
Reload CMail Message
See the manual page for cmail(6).
Exit Exits from xboard. The shifted "Q" key is a keyboard equivalent.
Tells the chess engine to play White.
Tells the chess engine to play Black.
Plays a game between two chess engines.
Puts XBoard in analysis mode on the current edited position or game. This mode
requires that you use a chess engine that supports analysis, such as Crafty; GNU
Chess will not work. See the manual section GETTING CRAFTY for more information
on getting and installing Crafty.
This mode lets you load a game from a file (PGN, etc.) and use a chess engine to
interactively analyze it. This mode requires that you use a chess engine that
supports analysis, such as Crafty; GNU Chess will not work. See the manual sec-
tion GETTING CRAFTY for more information on getting and installing Crafty.
This is the normal mode when xboard is connected to a chess server. If you have
moved into Edit Game or Edit Position mode, you can select this option to get out.
To use xboard in ICS mode, run it in the foreground with the -ics option, and use
the terminal you started it from to type commands and receive text responses from
the chess server. Useful ICS commands include who to see who is logged on, games
to see what games are being played, match to challenge another player to a game,
observe to observe an ongoing game, examine or oldmoves to review a recently com-
pleted game, and of course help.
Some special xboard features are activated when you are in examine or bsetup mode
on ICS. See the descriptions of the menu commands Forward, Backward, Pause, ICS
Client, and Stop Examining below. You can also issue the ICS position-editing
commands with the mouse. Move pieces by dragging with mouse button 1. To drop a
new piece on a square, press mouse button 2 or 3 over the square. This brings up
a menu of white pieces (button 2) or black pieces (button 3). Additional menu
choices let you empty the square or clear the board. Click on the White or Black
clock to set the side to play. You cannot set the side to play or drag pieces to
arbitrary squares while examining on ICC, but you can do so in bsetup mode on
If you are playing a bughouse game on the ICS, you can drop an offboard piece by
pressing mouse button 2 or 3 over an empty square to bring up a piece menu. It
makes no difference which button you use. A list of the offboard pieces each
player has available is shown in the window title after the player's name.
Allows you to make moves for both Black and White, and to change moves after back-
ing up with the Backward command. The clocks do not run.
In chess engine mode, the chess engine continues to check moves for legality but
does not participate in the game. You can bring the chess engine back into the
game by selecting Machine White, Machine Black, or Two Machines.
In ICS mode, the moves are not sent to the ICS: Edit Game takes xboard out of ICS
Client mode and lets you edit games locally. If you want to edit games on ICS in
a way that other ICS users can see, use the ICS examine command or start an ICS
match against yourself.
Lets you set up an arbitrary board position. Use mouse button 1 to drag pieces to
new squares, or to delete a piece by dragging it off the board or dragging an
empty square on top of it. To drop a new piece on a square, press mouse button 2
or 3 over the square. This brings up a menu of white pieces (button 2) or black
pieces (button 3). Additional menu choices let you empty the square or clear the
board. You can set the side to play next by clicking on the White or Black indi-
cator at the top of the screen. Selecting Edit Position causes xboard to discard
all remembered moves in the current game.
In ICS mode, changes made to the position by Edit Position are not sent to the
ICS: Edit Position takes xboard out of ICS Client mode and lets you edit posi-
tions locally. If you want to edit positions on ICS in a way that other ICS users
can see, use the ICS examine command, or start an ICS match against yourself.
(See also the ICS Client topic above.)
Training mode lets you interactively guess the moves of a game for one of the
players. You guess the next move of the game by playing the move on the board. If
the move played matches the next move of the game, the move is accepted and the
opponent's response is autoplayed. If the move played is incorrect, an error mes-
sage is displayed. You can select this mode only while loading a game (that is,
after selecting Load Game from the File menu). While xboard is in Training mode,
the navigation buttons are disabled.
Show Game List
Shows or hides the list of games generated by the last Load Game command.
Lets you edit the PGN (portable game notation) tags for the current game. After
editing, the tags must still conform to the PGN tag syntax:
<tag-section> ::= <tag-pair> <tag-section>
<tag-pair> ::= [ <tag-name> <tag-value> ]
<tag-name> ::= <identifier>
<tag-value> ::= <string>
See the PGN Standard for full details. Here is an example:
[Event "Portoroz Interzonal"]
[Site "Portoroz, Yugoslavia"]
[White "Robert J. Fischer"]
[Black "Bent Larsen"]
Any characters that do not match this syntax are silently ignored. Note that the
PGN standard requires all games to have at least the seven tags shown above. Any
that you omit will be filled in by xboard with "?" (unknown value), or "-" (inap-
Adds or modifies a comment on the current position. Comments are saved by Save
Game and are displayed by Load Game, Forward, and Backward.
ICS Input Box
If this mode is on in ICS mode, xboard creates an extra window that you can use
for typing in ICS commands. The input box is especially useful if you want to
type in something long or do some editing on your input, because output from ICS
doesn't get mixed in with your typing as it would in the main terminal window.
Pause Pauses updates to the board, and if you are playing against a local chess engine,
also pauses your clock. To continue, select Pause again, and the display will
automatically update to the latest position. The [P] button and keyboard "p" key
If you select Pause when you are playing against a local chess engine and it is
not your move, the engine's clock will continue to run and it will eventually make
a move, at which point both clocks will stop. Since board updates are paused,
however, you will not see the move until you exit from Pause mode (or select For-
ward). This behavior is meant to simulate adjournment with a sealed move.
If you select Pause while you are in examine mode on ICS, you can step backward
and forward in the current history of the examined game without affecting the
other observers and examiners. Select Pause again to reconnect yourself to the
current state of the game on ICS.
If you select Pause while you are loading a game, the game stops loading. You can
load more moves manually by selecting Forward, or resume automatic loading by
selecting Pause again.
Accept Accepts a pending ICS match offer. If there is more than one offer pending, you
will have to type in a more specific command instead of using this menu choice.
Decline Declines a pending ICS offer (match, draw, adjourn, etc.). If there is more than
one offer pending, you will have to type in a more specific command instead of
using this menu choice.
Calls your opponent's flag, claiming a win on time, or claiming a draw if you are
both out of time. You can also call your opponent's flag by clicking on his clock
or by pressing the keyboard "t" key.
Draw Offers a draw to your opponent, accepts a pending draw offer from your opponent,
or claims a draw by repetition or the 50-move rule, as appropriate. The "d" key
is a keyboard equivalent.
Adjourn Asks your opponent to agree to adjourning the current game, or agrees to a pending
adjournment offer from your opponent.
Abort Asks your opponent to agree to aborting the current game, or agrees to a pending
abort offer from your opponent. An aborted ICS game ends immediately without
affecting either player's rating.
Resign Resigns the game to your opponent. The shifted "R" key is a keyboard equivalent.
Ends your participation in observing a game, by issuing the ICS observe command
with no arguments.
Ends your participation in examining a game, by issuing the ICS unexamine command.
Steps backward through a series of remembered moves. The [<] button and the "b"
key are equivalents. In addition, pressing the Control key steps back one move,
and releasing it steps forward again.
In most modes, Backward only lets you look back at old positions; it does not
retract moves. This is the case if you are playing against a local chess engine,
playing or observing a game on the ICS, or loading a game. If you select Backward
in any of these situations, you will not be allowed to make a different move. Use
Retract Move or Edit Game if you want to change past moves.
If you are examining a game on ICS, the behavior of Backward depends on whether
xboard is in Pause mode. If Pause mode is off, Backward issues the ICS backward
command, which backs up everyone's view of the game and allows you to make a dif-
ferent move. If Pause mode is on, Backward only backs up your local view.
Forward Steps forward through a series of remembered moves (undoing the effect of Back-
ward) or forward through a game file. The [>] button and the f key are equiva-
If you are examining a game on ICS, the behavior of Forward depends on whether
xboard is in Pause mode. If Pause mode is off, Forward issues the ICS forward
command, which moves everyone's view of the game forward along the current line.
If Pause mode is on, Forward only moves your local view forward, and it will not
go past the position that the game was in when you paused.
Back to Start
Jumps backward to the first remembered position in the game. The [<<] button and
the shifted "B" key are equivalents.
In most modes, Back to Start only lets you look back at old positions; it does not
retract moves. This is the case if you are playing against a local chess engine,
playing or observing a game on the ICS, or loading a game. If you select Back to
Start in any of these situations, you will not be allowed to make different moves.
Use Retract Move or Edit Game if you want to change past moves; or use Reset to
start a new game.
If you are examining a game on ICS, the behavior of Back to Start depends on
whether xboard is in Pause mode. If Pause mode is off, Back to Start issues the
ICS backward 999999 command, which backs up everyone's view of the game to the
start and allows you to make different moves. If Pause mode is on, Back to Start
only backs up your local view.
Forward to End
Jumps forward to the last remembered position in the game. The [>>] button and
the shifted "F" key are equivalents.
If you are examining a game on ICS, the behavior of Forward to End depends on
whether xboard is in Pause mode. If Pause mode is off, Forward to End issues the
ICS forward 999999 command, which moves everyone's view of the game forward to the
end of the current line. If Pause mode is on, Forward to End only moves your
local view forward, and it will not go past the position that the game was in when
Revert If you are examining a game on ICS and Pause mode is off, issues the ICS command
Discards all remembered moves of the game beyond the current position. Puts
xboard into Edit Game mode if it was not there already.
Forces the chess engine to move immediately. May not work with all chess engines.
Retracts your last move. When playing a local chess engine, you can do this only
after the engine has replied to your move; if it is still thinking, use Move Now
first. In ICS mode, Retract Move issues the command takeback 1 or takeback 2
depending on whether it is your opponent's move or yours.
If this option is off, xboard brings up a dialog box whenever you move a pawn to
the last rank, asking what piece you want to promote it to. If the option is on,
your pawns are always promoted to queens. Your opponent can still underpromote.
If Animate Dragging is on, while you are dragging a piece with the mouse, an image
of the piece follows the mouse cursor. If Animate Dragging is off, there is no
visual feedback while you are dragging a piece, but if Animate Moving is on, the
move will be animated when it is complete.
If Animate Moving is on, all piece moves are animated. An image of the piece is
shown moving from the old square to the new square when the move is completed
(unless the move was already animated by Animate Dragging). If Animate Moving is
off, a moved piece instantly disappears from its old square and reappears on its
new square when the move is complete.
If this option is on, any remarks made on ICS while you are observing or playing a
game are recorded as a comment on the current move. This includes remarks made
with the ICS commands say, tell, whisper, and kibitz. Limitation: remarks that
you type yourself are not recognized; xboard scans only the output from ICS, not
the input you type to it.
If this option is on and one player runs out of time before the other, xboard will
automatically call his flag, claiming a win on time. In ICS mode, Auto Flag will
only call your opponent's flag, not yours, and the ICS may award you a draw
instead of a win if you have insufficient mating material. In local chess engine
mode, xboard may call either player's flag and will not take material into
Auto Flip View
If the Auto Flip View option is on when you start a game, the board will be auto-
matically oriented so that your pawns move from the bottom of the window towards
If this option is on and you add a player to your gnotify list on ICS, xboard will
automatically observe all of that player's games, unless you are doing something
else (such as observing or playing a game of your own) when one starts. The games
are displayed from the point of view of the player on your gnotify list; that is,
his pawns move from the bottom of the window towards the top. Exceptions: If
both players in a game are on your gnotify list, if your ICS highlight variable is
set to 0, or if the ICS you are using does not properly support observing from
Black's point of view, you will see the game from White's point of view.
Auto Raise Board
If this option is on, whenever a new game begins, the chessboard window is
deiconized (if necessary) and raised to the top of the stack of windows.
If this option is on, at the end of every game xboard prompts you for a file name
and appends a record of the game to the file you specify. Disabled if the saveG-
ameFile option is set, as in that case all games are saved to the specified file.
If this option is on, xboard displays the board as usual but does not display
pieces or move highlights. You can still move in the usual way (with the mouse or
by typing moves in ICS mode), even though the pieces are invisible.
If this option is on, whenever a move is completed, the moved piece flashes. The
number of times to flash is set by the flashCount command-line option; it defaults
to 3 if Flash Moves is first turned on from the menu.
Inverts your view of the chess board for the duration of the current game. Start-
ing a new game returns the board to normal. The "v" key is a keyboard equivalent.
If you are playing a game on the ICS, the board is always oriented at the start of
the game so that your pawns move from the bottom of the window towards the top.
Otherwise, the starting orientation is determined by the flipView command line
option; if it is False (the default), White's pawns move from bottom to top at the
start of each game; if it is True, Black's pawns move from bottom to top.
Get Move List
If this option is on, whenever xboard receives the first board of a new ICS game
(or a different ICS game from the one it is currently displaying), it retrieves
the list of past moves from the ICS. You can then review the moves with the For-
ward and Backward commands or save them with Save Game. You might want to turn
off this option if you are observing several blitz games at once, to keep from
wasting time and network bandwidth fetching the move lists over and over. When
you turn this option on from the menu, xboard immediately fetches the move list of
the current game (if any).
Highlight Last Move
If Highlight Last Move is on, after a move is made, the starting and ending
squares remain highlighted. In addition, after you use Backward or Back to Start,
the starting and ending squares of the last move to be unmade are highlighted.
If this option is on, xboard alerts you by playing a sound after each of your
opponent's moves (or after every move if you are observing a game on the Internet
Chess Server). The sound is not played after moves you make or moves read from a
saved game file. By default, the sound is the terminal bell, but on some systems
you can change it to a sound file using the soundMove option; see below.
If you turn on this option when using xboard with the Internet Chess Server, you
will probably want to give the set bell 0 command to the ICS, since otherwise the
ICS will ring the terminal bell after every move.
When this option is on, an alarm sound is played when your clock counts down to
the icsAlarmTime (by default, 5 seconds) in an ICS game. For games with time con-
trols that include an increment, the alarm will sound each time the clock counts
down to the icsAlarmTime. By default, the alarm sound is the terminal bell, but
on some systems you can change it to a sound file using the soundIcsAlarm option;
Old Save Style
If this option is off, xboard saves games in PGN (portable game notation) and
positions in FEN (Forsythe-Edwards notation). If the option is on, a save style
that is compatible with older versions of xboard is used instead. The old posi-
tion style is more human-readable than FEN; the old game style has no particular
If this option is off (or if you are using a chess engine that does not support
periodic updates), the analysis window will be updated only when the analysis
changes. If this option is on, the Analysis Window will be updated every two sec-
Ponder Next Move
If this option is off, the chess engine will think only when it is on move. If
the option is on, the engine will also think while waiting for you to make your
Popup Exit Message
If this option is on, when xboard wants to display a message just before exiting,
it brings up a modal dialog box and waits for you to click OK before exiting. If
the option is off, xboard prints the message to standard error (the terminal) and
Popup Move Errors
If this option is off, when you make an error in moving (such as attempting an
illegal move or moving the wrong color piece), the error message is displayed in
the message area. If the option is on, move errors are displayed in small popup
windows like other errors. You can dismiss an error popup either by clicking its
OK button or by clicking anywhere on the board, including downclicking to start a
Premove If this option is on while playing a game on ICS, you can register your next
planned move before it is your turn. Move the piece with the mouse in the ordi-
nary way, and the starting and ending squares will be highlighted with a special
color (red by default). When it is your turn, if your registered move is legal,
xboard will send it to ICS immediately; if not, it will be ignored and you can
make a different move. If you change your mind about your premove, either make a
different move, or double-click on any piece to cancel the move entirely.
If this option is on, xboard will automatically issue an ICS set shout 0 command
whenever you start an ICS game and a set shout 1 command whenever you finish one.
Thus you will not be distracted by shouts from other ICS users while playing.
If this option is on, xboard displays algebraic coordinates along the board's left
and bottom edges.
If this option is on, the chess engine's notion of the score and best line of play
from the current position is displayed as it is thinking. The score indicates how
many pawns ahead (or if negative, behind) the engine thinks it is. When GNU Chess
is thinking on your time, this thinking is not shown if GNU Chess was compiled
with the -DQUIETBACKGROUND option. In matches between two machines, the score is
prefixed by W or B to indicate whether the display is of White's thinking or
Black's, and thinking on the opponent's time is never shown.
If this option is on, xboard tests whether moves you try to make with the mouse
are legal, and refuses to let you make an illegal move. Moves loaded from a file
with Load Game are also checked. If the option is off, all moves are accepted,
but if a local chess engine or the ICS is active, they will still reject illegal
moves. Turning off this option is useful if you are playing a chess variant with
rules that xboard does not understand. (Bughouse, suicide, and wild variants
where the king may castle after starting on the d file are generally supported
with Test Legality on.)
Displays the xboard info file in a new window. For this feature to work, you must
have the GNU info program installed on your system, and the file xboard.info must
either be present in the current working directory, or have been installed by the
make install command when you built xboard.
Displays this man page in a new window. For this feature to work, the file
xboard.6 must have been installed by the make install command when you built
xboard, and the directory it was placed in must be on the search path for your
system's man(1) command.
Hint Displays a move hint from the local chess engine.
Book Displays a list of possible moves from the local chess engine's opening book. The
first column gives moves, the second column gives one possible response for each
move, and the third column shows the number of lines in the book that include the
move from the first column. If you select this option and nothing happens, the
chess engine is out of its book or does not support this command.
Shows the current xboard version number.
Other shortcut keys
Iconize Pressing the i or c key iconizes xboard. The graphical icon displays a white
knight if it is White's move, or a black knight if it is Black's move. If your X
window manager displays only text icons, not graphical ones, check its documenta-
tion; there is probably a way to enable graphical icons. If you are running the
Motif window manager mwm(1), add these lines to your .Xdefaults file and restart
Mwm*iconDecoration: activelabel label image
The first line above enables graphical icons in mwm; you don't need it if you
already have them. The next two lines force the white knights to come out white
and the black knights black. Unfortunately these resources can't be set from
inside xboard; you have to set them in your .Xdefaults.
You can add or remove xboard shortcut keys using the X resource form.translations. Here
is an example of what would go in your .Xdefaults file:
Shift<Key>?: AboutGameProc() \n \
<Key>y: AcceptProc() \n \
<Key>n: DeclineProc() \n \
Binding a key to NothingProc makes it do nothing, thus removing it as a shortcut key. The
xboard functions that can be bound to keys are:
AbortProc, AboutGameProc, AboutProc, AcceptProc,
AdjournProc, AlwaysQueenProc, AnalysisModeProc,
AnalyzeFileProc, AnimateDraggingProc, AnimateMovingProc,
AutobsProc, AutoflagProc, AutoflipProc, AutoraiseProc,
AutosaveProc, BackwardProc, BlindfoldProc, BookProc,
CallFlagProc, CopyGameProc, CopyPositionProc, DebugProc,
DeclineProc, DrawProc, EditCommentProc, EditGameProc,
EditPositionProc, EditTagsProc, EnterKeyProc,
FlashMovesProc, FlipViewProc, ForwardProc,
GetMoveListProc, HighlightLastMoveProc, HintProc,
Iconify, IcsAlarmProc, IcsAlarmProc, IcsClientProc,
IcsInputBoxProc, InfoProc, LoadGameProc,
LoadNextGameProc, LoadNextPositionProc, LoadPositionProc,
LoadPrevGameProc, LoadPrevPositionProc, LoadSelectedProc,
MachineBlackProc, MachineWhiteProc, MailMoveProc,
ManProc, MoveNowProc, MoveSoundProc, NothingProc,
OldSaveStyleProc, PasteGameProc, PastePositionProc,
PauseProc, PeriodicUpdatesProc, PonderNextMoveProc,
PopupExitMessageProc, PopupMoveErrorsProc, PremoveProc,
QuietPlayProc, QuitProc, ReloadCmailMsgProc,
ReloadGameProc, ReloadPositionProc, RematchProc,
ResetProc, ResignProc, RetractMoveProc, RevertProc,
SaveGameProc, SavePositionProc, ShowCoordsProc,
ShowGameListProc, ShowThinkingProc, StopExaminingProc,
StopObservingProc, TestLegalityProc, ToEndProc,
ToStartProc, TrainingProc, TruncateGameProc, and
This section documents the command-line options to xboard. You can set these options in
two ways: by typing them on the shell command line you use to start xboard, or by setting
them as X resources (typically in your .Xdefaults file). Many of the options cannot be
changed while xboard is running; others set the initial state of items that can be changed
with the Options menu.
Most of the options have both a long name and a short name. To turn a boolean option on
or off from the command line, either give its long name followed by the value True or
False (-longOptionName True), or give just the short name to turn the option on (-opt), or
the short name preceded by "x" to turn the option off (-xopt). For options that take
strings or numbers as values, you can use the long or short option names interchangeably.
Each option corresponds to an X resource with the same name, so if you like, you can set
options in your .Xdefaults file or in a file named XBoard in your home directory. For
options that have two names, the longer one is the name of the corresponding X resource;
the short name is not recognized. To turn a boolean option on or off as an X resource,
give its long name followed by the value True or False (XBoard*longOptionName: True).
Chess Engine Options
All of these options apply to both the GNU Chess and Crafty chess engines.
-tc or -timeControl minutes[:seconds]
Each player begins with his clock set to the timeControl period. Default: 5 min-
utes. The additional options movesPerSession and timeIncrement are mutually
-mps or -movesPerSession moves
When both players have made movesPerSession moves, a new timeControl period is
added to both clocks. Default: 40 moves.
-inc or -timeIncrement seconds
If this option is specified, movesPerSession is ignored. Instead, after each
player's move, timeIncrement seconds are added to his clock. Use -timeIncrement 0
if you want to require the entire game to be played in one timeControl period,
with no increment. Default: -1, which specifies movesPerSession mode.
-clock/-xclock or -clockMode True/False
Determines whether or not to display the chess clocks. If clockMode is False, the
clocks are not shown, but the side that is to play next is still highlighted.
Also, unless searchTime is set, the chess engine still keeps track of the clock
time and uses it to determine how fast to make its moves.
-st or -searchTime minutes[:seconds]
Tells the chess engine to spend at most the given amount of time searching for
each of its moves. Without this option, the engine chooses its search time based
on the number of moves and amount of time remaining until the next time control.
Setting this option also sets clockMode to False.
-depth or -searchDepth number
Tells the chess engine to look ahead at most the given number of moves when
searching for a move to make. Without this option, the engine chooses its search
depth based on the number of moves and amount of time remaining until the next
time control. With the option, the engine will cut off its search early if it
reaches the specified depth.
-thinking/-xthinking or -showThinking True/False
Sets the Show Thinking menu option. Default: False.
-ponder/-xponder or -ponderNextMove True/False
Sets the Ponder Next Move menu option. Default: True.
-mg or -matchGames n
Automatically runs an n-game match between two chess engines, with alternating
colors. If the loadGameFile or loadPositionFile option is set, xboard starts each
game with the given opening moves or the given position; otherwise, the games
start with the standard initial chess position. If the saveGameFile option is
set, a move record for the match is appended to the specified file. If the save-
PositionFile option is set, the final position reached in each game of the match
is appended to the specified file. When the match is over, xboard displays the
match score and exits. Default: 0 (do not run a match).
-mm/-xmm or -matchMode True/False
Provided for backward compatibility. If true and matchGames is 0, sets matchGames
-fcp or -firstChessProgram program
Name of first chess engine. Default: gnuchessx.
-scp or -secondChessProgram program
Name of second chess engine. A second chess engine is started only in Two
Machines (match) mode. Default: gnuchessx.
-fb/-xfb or -firstPlaysBlack True/False
In games between two chess engines, firstChessProgram normally plays white. (This
is a change from earlier versions of xboard.) If this option is True,
firstChessProgram plays black. In a multi-game match, this option affects the
colors only for the first game; they still alternate in subsequent games.
-fh or -firstHost host
-sh or -secondHost host
Hosts on which the chess engines are to be run. The default for each is local-
host. If you specify another host, xboard uses rsh(1) to run the chess engine
there. (You can substitute a different remote shell program for rsh using the
remoteShell option described below.)
-fd or -firstDirectory dir
-sd or -secondDirectory dir
Working directories in which the chess engines are to be run. The default for
both is "", which means to run the chess engine in the same working directory as
xboard itself. (See the CHESSDIR environment variable.) This option is effective
only when the chess engine is being run on the local host; it does not work if the
engine is run remotely using the -fh or -sh option.
The string that is sent to initialize each chess engine for a new game. Default:
Setting this option from the command line is tricky, because you must type in real
newline characters, including one at the end. In most shells you can do this by
entering a "\" character followed by a newline. It is easier to set the option
from your .Xdefaults file; in that case you can include the character sequence
"\n" in the string, and it will be converted to a newline.
If you change this option, don't remove the new command; it is required by all
chess engines to start a new game.
You can remove the random command if you like; including it causes GNU Chess to
randomize its move selection slightly so that it doesn't play the same moves in
every game. Even without random, GNU Chess randomizes its choice of moves from
its opening book. Crafty ignores this command; it randomizes by default.
You can also try adding other commands to the initString; see the GNU Chess or
Crafty documentation for details.
The string that is sent to the chess engine if its opponent is another computer
chess engine. The default is "computer\n". Probably the only useful alternative
is the empty string (""), which keeps the engine from knowing that it is playing
-reuse/-xreuse or -reuseFirst True/False
-reuse2/-xreuse2 or -reuseSecond True/False
If the option is False, xboard kills off the chess engine after every game and
starts it again for the next game. If the option is True (the default), xboard
starts the chess engine only once and uses it repeatedly to play multiple games.
Some chess engines may not work properly when reuse is turned on, such as versions
of Crafty earlier than 12.0, but otherwise new games will start faster if it is
This option specifies which version of the chess engine communication protocol to
use. By default, version-number is 2. In version 1, the "protover" command is
not sent to the engine; since version 1 is a subset of version 2, nothing else
changes. Other values for version-number are not supported.
Internet Chess Server Options
-ics/-xics or -internetChessServerMode True/False
Connect with an Internet Chess Server to play chess against its other users,
observe games they are playing, or review games that have recently finished.
-icshost or -internetChessServerHost host
The Internet host name or address of the chess server to connect to when in ICS
mode. Default: chessclub.com. See the file ics-addresses in the xboard source
distribution for a list of other addresses to try. If your site doesn't have a
working Internet name server, try specifying the host address in numeric form.
You may also need to specify the numeric address when using the icshelper option
with timestamp or timeseal (see below). At this writing, chessclub.com is
22.214.171.124 and freechess.org (formerly fics.onenet.net) is 126.96.36.199.
-icsport or -internetChessServerPort port-number
The port number to use when connecting to a chess server in ICS mode. Default:
-icshelper or -internetChessServerHelper prog-name
An external helper program used to communicate with the chess server. You would
set it to "timestamp" for ICC (chessclub.com) or "timeseal" for FICS
(freechess.org, eics.daimi.aau.dk, etc.), after obtaining the correct version of
timestamp or timeseal for your computer. See "help timestamp" on ICC and "help
timeseal" on FICS. This option is shorthand for "-useTelnet -telnetProgram pro-
-telnet/-xtelnet or -useTelnet True/False
This option is poorly named; it should be called useHelper. If set to True, it
instructs xboard to run an external program to communicate with the Internet Chess
Server. The program to use is given by the telnetProgram option. If the option
is False (the default), xboard opens a TCP socket and uses its own internal imple-
mentation of the telnet protocol to communicate with the ICS. See the FIREWALLS
section below for an explanation of when this option is useful.
This option is poorly named; it should be called helperProgram. It gives the name
of the telnet program to be used with the gateway and useTelnet options. The
default is telnet. The telnet program is invoked with the value of inter-
netChessServerHost as its first argument and the value of internetChessServerPort
as its second argument. See the FIREWALLS section below for an explanation of
when this option is useful.
If this option is set to a host name, xboard communicates with the Internet Chess
Server by using rsh(1) to run the telnetProgram on the given host, instead of
using its own internal implementation of the telnet protocol. You can substitute
a different remote shell program for rsh with the remoteShell option described
below. See the FIREWALLS section below for an explanation of when this option is
-internetChessServerCommPort or -icscomm dev-name
If this option is set, xboard communicates with the ICS through the given charac-
ter I/O device instead of opening a TCP connection. Use this option if your sys-
tem does not have any kind of Internet connection itself (not even a SLIP or PPP
connection), but you do have dialup access (or a hardwired terminal line) to an
Internet service provider from which you can telnet to the ICS.
The support for this option in xboard is minimal. You need to set all communica-
tion parameters and tty modes before you enter xboard.
Use a script something like this:
stty raw -echo 9600 > /dev/tty00
xboard -ics -icscomm /dev/tty00
Here replace /dev/tty00 with the name of the device that your modem is connected
to. You might have to add several more options to these stty commands. See the
man pages for stty(1) and tty(4) if you run into problems. Also, on many systems
stty works on its standard input instead of standard output, so you have to use
"<" instead of ">".
If you are using linux, try starting with the script below. Change it as neces-
sary for your installation.
# configure modem and fire up xboard
# configure modem
( stty 2400 ; stty raw ; stty hupcl ; stty -clocal
stty ignbrk ; stty ignpar ; stty ixon ; stty ixoff
stty -iexten ; stty -echo ) < /dev/modem
xboard -ics -icscomm /dev/modem
After you start xboard in this way, type whatever commands are necessary to dial
out to your Internet provider and log in. Then telnet to ICS, using a command
like telnet chessclub.com 5000. Important: See the paragraph in the LIMITATIONS
section below about extra echoes.
-icslogon or -internetChessServerLogonScript file-name
Whenever xboard connects to the Internet Chess Server, if it finds a file with the
name given in this option, it feeds the file's contents to the ICS as commands.
The default file name is .icsrc. Usually the first two lines of the file should
be your ICS user name and password. The file can be either in $CHESSDIR, in
xboard's working directory if CHESSDIR is not set, or in your home directory.
If you experience trouble logging onto an ICS using the -icslogon option, insert-
ing some delay between characters of the login script may help. This option
inserts delay milliseconds of delay per character. Good values to try are 100 and
-icsinput/-xicsinput or -internetChessServerInputBox True/False
Sets ICS Input Box on the mode menu. Default: False.
-autocomm/-xautocomm or -autoComment True/False
Sets the Auto Comment menu option. Default: False.
-autoflag/-xautoflag or -autoCallFlag True/False
Sets the Auto Flag menu option. Default: False.
-autobs/-xautobs or -autoObserve True/False
Sets the Auto Observe menu option. Default: False.
-moves/-xmoves or -getMoveList True/False
Sets the Get Move List menu option. Default: True.
-alarm/-xalarm or -icsAlarm True/False
Sets the ICS Alarm menu option. Default: True.
Sets the time in milliseconds for the ICS Alarm menu option. Default: 5000.
-pre/-xpre or -premove True/False
Sets the Premove menu option. Default: True.
-quiet/-xquiet or -quietPlay True/False
Sets the Quiet Play menu option. Default: False. Default: False.
-colorize/-xcolorize or -colorizeMessages TrueFalse
Setting colorizeMessages to True causes xboard to colorize the messages received
from the ICS. Colorization works only if your xterm supports ISO 6429 escape
sequences for changing text colors.
These options set the colors used when colorizing ICS messages. All ICS messages
are grouped into one of these categories: shout, sshout, channel 1, other channel,
kibitz, tell, challenge, request (including abort, adjourn, draw, pause, and take-
back), seek, or normal (all other messages).
Each foreground or background argument can be one of the following: black, red,
green, yellow, blue, magenta, cyan, white, or default. Here "default" means the
default foreground or background color of your xterm. Bold can be 1 or 0. If
background is omitted, "default" is assumed; if bold is omitted, 0 is assumed.
Here is an example of how to set the colors in your .Xdefaults file. The colors
shown here are the default values; you will get them if you turn -colorize on
without specifying your own colors.
xboard*colorSShout: green, black, 1
xboard*colorChannel: cyan, black, 1
xboard*colorKibitz: magenta, black, 1
xboard*colorTell: yellow, black, 1
xboard*colorChallenge: red, black, 1
If this option is set to a sound-playing program that is installed and working on
your system, xboard can play sound files when certain events occur, listed below.
The default program name is "play". If any of the sound options is set to "$",
the event rings the terminal bell by sending a ^G character to standard output,
instead of playing a sound file. If an option is set to the empty string "", no
sound is played for that event.
These sounds are triggered in the same way as the colorization events described
above. They all default to "", no sound. They are played only if the col-
orizeMessages is on.
This sound is used by the Move Sound menu option. Default: "$".
This sound is used by the ICS Alarm menu option. Default: "$".
This sound is played when you win an ICS game. Default: "" (no sound).
This sound is played when you lose an ICS game. Default: "" (no sound).
This sound is played when you draw an ICS game. Default: "" (no sound).
This sound is played when an ICS game that you are participating in is aborted,
adjourned, or otherwise ends inconclusively. Default: "" (no sound).
Here is an example of how to set the sounds in your .Xdefaults file.
Load and Save Options
-lgf or -loadGameFile file
-lgi or -loadGameIndex index
If the loadGameFile option is set, xboard loads the specified game file at
startup. The file name "-" specifies the standard input. If there is more than
one game in the file, xboard pops up a menu of the available games, with entries
based on their PGN (portable game notation) tags. If the loadGameIndex option is
set to N, the menu is suppressed and the Nth game found in the file is loaded
immediately. The menu is also suppressed if matchMode is enabled or if the game
file is a pipe; in these cases the first game in the file is loaded immediately.
Use the pxboard shell script if you want to pipe files containing multiple games
into xboard and still see the menu.
-td or -timeDelay seconds
Time delay between moves during Load Game. Fractional seconds are allowed; try
-td 0.4. A time delay value of -1 tells xboard not to step through game files
automatically. Default: 1 second.
-sgf or -saveGameFile file
If this option is set, xboard appends a record of every game played to the speci-
fied file. The file name "-" specifies the standard output.
-autosave/-xautosave or -autoSaveGames True/False
Sets the Auto Save menu option. Ignored if saveGameFile is set. Default: False.
-lpf or -loadPositionFile file
-lpi or -loadPositionIndex index
If the loadPositionFile option is set, xboard loads the specified position file at
startup. The file name "-" specifies the standard input. If the loadPositionIn-
dex option is set to N, the Nth position found in the file is loaded; otherwise
the first position is loaded.
-spf or -savePositionFile file
If this option is set, xboard appends the final position reached in every game
played to the specified file. The file name "-" specifies the standard output.
-oldsave/-xoldsave or -oldSaveStyle True/False
Sets the Old Save Style menu option. Default: False.
User Interface Options
standard Xt options
xboard accepts standard Xt options like -display, -geometry, and -iconic.
-movesound/-xmovesound or -ringBellAfterMoves True/False
Sets the Move Sound menu option. Default: False. For upward compatibility,
-bell/-xbell are also accepted as abbreviations for this option.
-exit/-xexit or -popupExitMessage True/False
Sets the Popup Exit Message menu option. Default: True.
-popup/-xpopup or -popupMoveErrors True/False
Sets the Popup Move Errors menu option. Default: False.
-queen/-xqueen or -alwaysPromoteToQueen True/False
Sets the Always Queen menu option. Default: False.
-legal/-xlegal or -testLegality True/False
Sets the Test Legality menu option. Default: True.
-size or -boardSize (sizeName | n1,n2,n3,n4,n5,n6,n7)
Determines how large the board will be, by selecting the pixel size of the pieces
and setting a few related parameters. The sizeName can be one of: Titanic, giving
129x129 pixel pieces, Colossal 116x116, Giant 108x108, Huge 95x95, Big 87x87,
Large 80x80, Bulky 72x72, Medium 64x64, Moderate 58x58, Average 54x54, Middling
49x49, Mediocre 45x45, Small 40x40, Slim 37x37, Petite 33x33, Dinky 29x29, Teeny
25x25, or Tiny 21x21. Pieces of all these sizes are built into xboard. Other
sizes can be used if you have them; see the pixmapDirectory and bitmapDirectory
options. The default depends on the size of your screen; it is approximately the
largest size that will fit without clipping.
You can select other sizes or vary other layout parameters by providing a list of
comma-separated values (with no spaces) as the argument. You do not need to pro-
vide all the values; for any you omit from the end of the list, defaults are taken
from the nearest built-in size. The value n1 gives the piece size, n2 the width
of the black border between squares, n3 the desired size for the clockFont, n4 the
desired size for the coordFont, n5 the desired size for the default font, n6 the
smallLayout flag (0 or 1), and n7 the tinyLayout flag (0 or 1). All dimensions
are in pixels. If the border between squares is eliminated (0 width), the various
highlight options will not work, as there is nowhere to draw the highlight. If
smallLayout is 1 and titleInWindow is True, the window layout is rearranged to
make more room for the title. If tinyLayout is 1, the labels on the menu bar are
abbreviated to one character each and the buttons in the button bar are made nar-
-coords/-xcoords or -showCoords True/False
Sets the Show Coords menu option. Default: False. The coordFont option specifies
what font to use.
-autoraise/-xautoraise or -autoRaiseBoard True/False
Sets the Auto Raise Board menu option. Default: True.
-autoflip/-xautoflip or -autoFlipView True/False
Sets the Auto Flip View menu option. Default: True.
-flip/-xflip or -flipView True/False
If Auto Flip View is not set, or if you are observing but not participating in a
game, then the positioning of the board at the start of each game depends on the
flipView option. If flipView is False (the default), the board is positioned so
that the white pawns move from the bottom to the top; if True, the black pawns
move from the bottom to the top. In any case, the Flip menu option can be used to
flip the board after the game starts.
-title/-xtitle or -titleInWindow True/False
If this option is True, xboard displays player names (for ICS games) and game file
names (for Load Game) inside its main window. If the option is False (the
default), this information is displayed only in the window banner. You probably
won't want to set this option unless the information is not showing up in the ban-
ner, as happens with a few X window managers.
-buttons/-xbuttons or -showButtonBar True/False
If this option is False, xboard omits the [<<] [<] [P] [>] [>>] button bar from
the window, allowing the message line to be wider. You can still get the func-
tions of these buttons using the menus or their keyboard shortcuts. Default:
-mono/-xmono or -monoMode True/False
Determines whether xboard displays its pieces and squares with two colors (True)
or four (False). You shouldn't have to specify monoMode; xboard will determine if
it is necessary.
-xflash These options enable flashing of pieces when they land on their destination
square. flashCount tells XBoard how many times to flash a piece after it lands on
its destination square. flashRate controls the rate of flashing (flashes/sec).
Abbreviations: flash sets flashCount to 3. xflash sets flashCount to 0.
Defaults: flashCount=0 (no flashing), flashRate=5.
-highlight/-xhighlight or -highlightLastMove True/False
Sets the Highlight Last Move menu option. Default: False.
-blind/-xblind or -blindfold True/False
Sets the Blindfold menu option. Default: False.
The font used for the clocks. If the option value is a pattern that does not
specify the font size, xboard tries to choose an appropriate font for the board
size being used. Default: -*-helvetica-bold-r-normal--*-*-*-*-*-*-*-*.
The font used for rank and file coordinate labels if showCoords is True. If the
option value is a pattern that does not specify the font size, xboard tries to
choose an appropriate font for the board size being used. Default: -*-helvetica-
The font used for popup dialogs, menus, comments, etc. If the option value is a
pattern that does not specify the font size, xboard tries to choose an appropriate
font for the board size being used. Default: -*-helvetica-medium-r-nor-
In the font selection algorithm, a nonscalable font will be preferred over a scal-
able font if the nonscalable font's size differs by tol pixels or less from the
desired size. A value of -1 will force a scalable font to always be used if
available; a value of 0 will use a nonscalable font only if it is exactly the
right size; a large value (say 1000) will force a nonscalable font to always be
used if available. Default: 4.
-bm or -bitmapDirectory dir
-pixmap or -pixmapDirectory dir
These options control what piece images xboard uses. The xboard distribution
includes one set of pixmap pieces in xpm format, in the directory pixmaps, and two
sets of bitmap pieces in xbm format, in the directories bitmaps and bit-
maps.xchess. Pixmap pieces give a better appearance on the screen: the white
pieces have dark borders, and the black pieces have opaque internal details. With
bitmaps, neither piece color has a border, and the internal details are transpar-
ent; you see the square color or other background color through them.
If xboard is configured and compiled on a system that includes libXpm, the X
pixmap library, the xpm pixmap pieces are compiled in as the default. A different
xpm piece set can be selected at runtime with the -pixmapDirectory option, or a
bitmap piece set can be selected with the -bitmapDirectory option.
If xboard is configured and compiled on a system that does not include libXpm (or
the --disable-xpm option is given to the configure program), the bitmap pieces are
compiled in as the default. It is not possible to use xpm pieces in this case,
but pixmap pieces in another format called "xim" can be used by giving the
-pixmapDirectory option. Or again, a different bitmap piece set can be selected
with the -bitmapDirectory option.
Files in the bitmapDirectory must be named as follows: The first character of a
piece bitmap name gives the piece it represents (p, n, b, r, q, or k), the next
characters give the size in pixels, the following character indicates whether the
piece is solid or outline (s or o), and the extension is ".bm". For example, a
solid 80x80 knight would be named "n80s.bm". The outline bitmaps are used only in
monochrome mode. If bitmap pieces are compiled in and the bitmapDirectory is
missing some files, the compiled in pieces are used instead.
If the bitmapDirectory option is given, it is also possible to replace xboard's
icons and menu checkmark, by supplying files named "icon_white.bm",
"icon_black.bm", and "checkmark.bm".
You can import pixmap pieces from the ZIICS distribution by using the zic2xpm pro-
gram to convert them. This program produces both xpm and xim pixmaps, so you can
use these pieces even if you do not have xpm support compiled into your xboard.
ZIICS provides a large number of piece sets to choose from. Here's how to import
1) Download the ZIICS distribution. It is available from
2) Unzip it into a directory, for example:
unzip -L ziics131.exe -d ~/ziics
3) Pick a chess set you want to use, for example the FRITZ4 set. Create a direc-
tory to hold the pieces, then run the zic2xpm program to create the pieces:
(The zic2xpm program is in the directory where xboard was compiled, in case you
didn't do a make install.)
4) Now, just add the -pixmapDirectory option when you start xboard:
xboard -pixmapDirectory ~/fritz4
Or add the option to your .Xdefaults file:
Colors to use for the pieces, squares, and square highlights. Defaults:
If you are using a grayscale monitor, try setting the colors to:
-drag/-xdrag or -animateDragging True/False
Sets the Animate Dragging menu option. Default: True.
-animate/-xanimate or -animateMoving True/False
Sets the Animate Moving menu option. Default: True.
Number of milliseconds delay between each animation frame when Animate Moves is
-ncp/-xncp or -noChessProgram True/False
If this option is True, xboard acts as a passive chessboard; it does not start a
chess engine at all. Turning on this option also turns off clockMode. Default:
-mode or -initialMode modename
If this option is given, xboard selects the given modename from the Mode menu
after starting and (if applicable) processing the loadGameFile or loadPositionFile
option. Default: "" (no selection). Other supported values are MachineWhite,
MachineBlack, TwoMachines, Analysis, AnalyzeFile, EditGame, EditPosition, and
Activates preliminary, partial support for playing chess variants against a local
engine or editing variant games. This flag is not needed in ICS mode. Recognized
variant names are:
normal Normal chess
wildcastle Shuffle chess, king can castle from d file
nocastle Shuffle chess, no castling allowed
fischerandom Fischer Random shuffle chess
bughouse Bughouse, ICC/FICS rules
crazyhouse Crazyhouse, ICC/FICS rules
losers Lose all pieces or get mated (ICC wild 17)
suicide Lose all pieces including king (FICS)
giveaway Try to have no legal moves (ICC wild 26)
twokings Weird ICC wild 9
kriegspiel Opponent's pieces are invisible
atomic Capturing piece explodes (ICC wild 27)
3check Win by giving check 3 times (ICC wild 25)
shatranj An ancient precursor of chess (ICC wild 28)
unknown Catchall for other unknown variants
In the shuffle variants, xboard does not shuffle the pieces, but you can do it by
hand using Edit Position. Some variants are supported only in ICS mode, including
fischerandom, bughouse, and kriegspiel. The winning/drawing conditions in crazy-
house (offboard interposition on mate), losers, suicide, giveaway, atomic, and
3check are not fully understood. In crazyhouse, xboard does not yet keep track of
offboard pieces. Shatranj is unsupported, but it may be usable if you turn off
-debug/-xdebug or -debugMode True/False
Turns on debugging printout.
-rsh or -remoteShell shell-name
Name of the command used to run programs remotely. The default is rsh or remsh,
determined when xboard is configured and compiled.
-ruser or -remoteUser user-name
User name on the remote system when running programs with the remoteShell. The
default is your local user name.
If you are using a chess engine that supports analysis, such as Crafty, you can use xboard
to analyze your games. GNU Chess does not support analysis. See the section titled GET-
TING CRAFTY for more information on obtaining and installing Crafty. There are a few ways
Analyzing a stored game (PGN, etc): Choose Analyze File from the Mode Menu. Type the
name of the file you wish to load. If the file contains multiple games, another
popup will appear to let you choose which game you want to analyze. Use the arrow
buttons to move through the game and watch the engine's analysis.
Setting up a position to analyze Choose Edit Position from the Mode Menu. Edit the
board (the right and middle mouse buttons bring up the black/white piece menus).
When finished editing, click on either the White or Black clock to tell xboard whose
turn it is to move. Choose Analysis Mode from the Mode Menu. Watch the analysis,
move pieces around, etc.
Analyzing a new game If you want to start a new analysis from a fresh board, choose
Reset Game from the File Menu, then choose Analysis Mode from the Mode Menu. Now
you can move pieces around and watch the engine's analysis.
Crafty is a chess engine written by Bob Hyatt (email@example.com). You can use XBoard to
play a game against Crafty, hook Crafty up to an ICS, or use Crafty to interactively ana-
lyze games and positions for you.
Crafty is a strong, rapidly evolving chess program. This rapid pace of development is
good, because it means Crafty is always getting better. This can sometimes cause problems
with backwards compatibility, but usually the latest version of Crafty will work well with
the latest version of xboard. Crafty can be obtained from its author's FTP site:
To use Crafty with XBoard, give the -fcp and -fd options as follows, where crafty's-direc-
tory is the directory in which you installed Crafty and placed its book and other support
xboard -fcp crafty -fd crafty's-directory
By default, xboard -ics communicates with an Internet Chess Server by opening a TCP socket
directly from the machine it is running on to the ICS. If there is a firewall between
your machine and the ICS, this won't work. Here are some recipes for getting around com-
mon kinds of firewalls using special options to xboard. Important: See the paragraph in
the LIMITATIONS section below about extra echoes.
Suppose that you can't telnet directly to ICS, but you can telnet to a firewall host, log
in, and then telnet from there to ICS. Let's say the firewall is called fire.wall.com.
Set command-line options as follows:
xboard -ics -icshost fire.wall.com -icsport 23
Or in your .Xdefaults file:
Then when you run xboard in ICS mode, you will be prompted to log in to the firewall host.
(This works because port 23 is the standard telnet login service.) Log in, then telnet to
ICS, using a command like telnet chessclub.com 5000, or whatever command the firewall pro-
vides for telnetting to port 5000.
If your firewall lets you telnet (or rlogin) to remote hosts, but doesn't let you telnet
to port 5000, you will have to find some other host outside the firewall that does let you
do this, and hop through it. For instance, suppose you have an account at foo.edu. Fol-
low the recipe above, but instead of typing telnet chessclub.com 5000 to the firewall,
type telnet foo.edu (or rlogin foo.edu), log in there, and then type telnet chessclub.com
Exception: chessclub.com itself lets you connect to the chess server on the default telnet
port (23), which is what you get if you don't specify a port to the telnet program. But
the other chess servers don't allow this.
Suppose that you can't telnet directly to ICS, but you can use rsh to run programs on a
firewall host, and that host can telnet to ICS. Let's say the firewall is called
rsh.wall.com. Set command-line options as follows:
xboard -ics -gateway rsh.wall.com -icshost chessclub.com
Or in your .Xdefaults file:
Then when you run xboard in ICS mode, it will connect to the ICS by using rsh to run the
command telnet chessclub.com 5000 on host rsh.wall.com.
Suppose that you can telnet anywhere you want, but you have to run a special program
called ptelnet to do so.
First, we'll consider the easy case, in which ptelnet chessclub.com 5000 gets you to the
chess server. In this case set command line options as follows:
xboard -ics -telnet -telnetProgram ptelnet
Or in your .Xdefaults file:
Then when you run xboard in ICS mode, it will issue the command ptelnet chessclub.com 5000
to connect to the ICS.
Next, suppose that ptelnet chessclub.com 5000 doesn't work; that is, your ptelnet program
doesn't let you connect to alternative ports. In this case, you will have to find some
other host outside the firewall that does let you do this, and hop through it. For
instance, suppose you have an account at foo.edu. Set command line options as follows:
xboard -ics -telnet -telnetProgram ptelnet -icshost foo.edu -icsport ""
Or in your .Xdefaults file:
Then when you run xboard in ICS mode, it will issue the command ptelnet foo.edu to connect
to your account at foo.edu. Log in there, then type telnet chessclub.com 5000.
ICC timestamp and FICS timeseal do not work through many firewalls. You can use them only
if your firewall gives a clean TCP connection with a full 8-bit wide path. If your fire-
wall allows you to get out only by running a special telnet program, you can't use time-
stamp or timeseal across it. But if you have access to a computer just outside your fire-
wall, and you have much lower netlag when talking to that computer than to the ICS, it
might be worthwhile running timestamp there. Follow the instructions above for hopping
through a host outside the firewall (foo.edu in the example), but run timestamp or time-
seal on that host instead of telnet.
Suppose that you have a SOCKS firewall that requires you to go through some extra level of
authentication, but after that will give you a clean 8-bit wide TCP connection to the
chess server. In that case, you could make a socksified version of xboard and run that.
If you are using timestamp or timeseal, you will need to socksify it, not xboard; this may
be difficult seeing that ICC and FICS do not provide source code for these programs.
Socksification is beyond the scope of this document, but see the SOCKS Web site at
Game and position files are found in the directory named by the CHESSDIR environment vari-
able. If this variable is not set, the current working directory is used. If CHESSDIR is
set, xboard actually changes its working directory to $CHESSDIR, so any files written by
the chess engine will be placed there too.
There is no way for two people running copies of xboard to play each other without going
through the Internet Chess Server.
Under some circumstances, your ICS password may be echoed when you log on.
If you are connecting to the ICS by running telnet, timestamp, or timeseal on an Internet
provider or firewall host, you may find that each line you type is echoed back an extra
time after you hit Return. If your Internet provider is a Unix system, you can probably
turn its echo off by typing stty -echo after you log in, and/or typing ^E-Return (control-
E followed by the Return key) to the telnet program after you have logged into ICS. It is
a good idea to do this if you can, because otherwise the extra echo can occasionally con-
fuse xboard's parsing routines.
The game parser recognizes only algebraic notation.
The internal move legality tester does not look at the game history, so in some cases it
misses illegal castling or en passant captures. It permits castling with the king on the
d file because this is possible in some "wild 1" games on ICS. However, if you attempt an
illegal move when using a chess engine or the ICS, xboard will accept the error message
that comes back, undo the move, and let you try another.
Fischer Random castling is not understood. You can probably play Fischer Random chess
successfully on ICS by typing castling moves into the ICS Interaction window, but they
will not be animated correctly, and saved games will not be loaded correctly if castling
FEN positions saved by xboard never include correct information about whether castling is
legal or how many half-moves have been made since the last irreversible move, and some-
times may not correctly indicate when en passant capture is available.
The mate detector does not understand that non-contact mate is not really mate in bug-
house. The only problem this causes while playing is minor: a "#" (mate indicator) char-
acter will show up after a non-contact mating move in the move list; xboard will not
assume the game is over at that point. However, if you are editing a game, Edit Game mode
will be terminated by a non-contact mate.
Some xboard functions may not work with versions of GNU Chess earlier than 4.0, patchlevel
77, or with versions of Crafty earlier than 15.11. A few functions work with GNU Chess
but not Crafty, or vice versa.
The menus may not work if your keyboard is in Caps Lock or Num Lock mode. This seems to
be a problem with the Athena menu widget, not an xboard bug.
Also see the ToDo file included with the distribution for many other possible bugs, limi-
tations, and ideas for improvement that have been suggested.
Report bugs and problems with xboard to <firstname.lastname@example.org>. Please use the script(1) pro-
gram to start a typescript, run xboard with the -debug option, and include the typescript
output in your message. Also tell us what kind of machine and what operating system ver-
sion you are using. The command "uname -a" will often tell you this. Here is a sample of
approximately what you should type:
Subject: Your short description of the problem
Your detailed description of the problem
If you improve xboard, please send a message about your changes, and we will get in touch
with you about merging them in to the main line of development.
AUTHORS AND CONTRIBUTORS
Tim Mann has been responsible for xboard versions 1.3 and beyond, and for WinBoard, a port
of xboard to Microsoft Win32 (Windows NT and Windows 95).
Mark Williams contributed the initial (WinBoard-only) implementation of many new features
added to both XBoard and WinBoard in version 4.1.0, including copy/paste, premove,
icsAlarm, autoFlipView, training mode, auto raise, and blindfold. Ben Nye contributed X
copy/paste code for XBoard.
Hugh Fisher added animated piece movement to xboard, and Henrik Gram added it to WinBoard.
Frank McIngvale added click/click moving, the Analysis modes, piece flashing, ZIICS
import, and ICS text colorization to xboard. Jochen Wiedmann ported xboard to the Amiga,
creating AmyBoard, and converted the documentation to texinfo. Elmar Bartel contributed
the new piece bitmaps for version 3.2. Evan Welsh wrote cmail. John Chanak contributed
the initial implementation of ICS mode. The color scheme and the old 80x80 piece bitmaps
were taken from Wayne Christopher's XChess program.
Chris Sears and Dan Sears wrote the original xboard; they were responsible for versions
1.0 through 1.2.
Copyright 1991 by Digital Equipment Corporation, Maynard, Massachusetts. Enhancements
Copyright 1992-95 Free Software Foundation, Inc.
XBoard's alternative piece bitmaps (bitmaps.xchess) are derived from the bitmaps in the
XChess program, which was written and is copyrighted by Wayne Christopher.
The following terms apply to Digital Equipment Corporation's copyright interest in XBoard:
All Rights Reserved
Permission to use, copy, modify, and distribute this software and its documentation
for any purpose and without fee is hereby granted, provided that the above copy-
right notice appear in all copies and that both that copyright notice and this per-
mission notice appear in supporting documentation, and that the name of Digital not
be used in advertising or publicity pertaining to distribution of the software
without specific, written prior permission.
DIGITAL DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL DIGITAL BE
LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER
RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEG-
LIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
PERFORMANCE OF THIS SOFTWARE.
The following terms apply to this enhanced version of XBoard distributed by the Free Soft-
This program is free software; you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the Free Software Founda-
tion; either version 2 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this
program; if not, write to the Free Software Foundation, Inc., 59 Temple Place -
Suite 330, Boston, MA 02111-1307, USA.
ZIICS is a separate copyrighted work of Andy McFarland (Zek on ICC). Use of ZIICS falls
under the ZIICS license, not the GPL.
GNU $Date: 2001/12/09 23:02:59 $ xboard(6)