gnugo - The GNU program to play the game of Go
[ --boardsize <num
>] [ --color <color
>] [ --komi <num
>] [ --quiet
[ -v, --version
] [ -h, --help
] [ --help debug
] [ --mode <mode
>] [ --replay
>] [ -l, --infile <filename
>] [ -L, --until
>] [ -o, --outfile <filename
>] [ --printsgf
>] [ -D, --depth <num
>] [ -B,
>] [ --score
] [ -a, --allpats
] [ -d, --debug <level
>] [ -w,
] [ -m, --moyo <level
>] [ -b, --benchmark num
[ -t, --trace
] [ -r, --seed num
GNU Go plays a game of Go against the user. It has many other features: it can
play against itself or another program, analyse and score a recorded game. GNU
Go is compliant with Go modem protocol, load and save game in the Smart Game
GNU Go default is a simple alpha-numeric board display, but you can use a client
such as CGoban
The game of Go
Go is a game of strategy between two players usually played on a 19x19 grid
. The two players put black and white stones
goban to enclose territory
. Go was invented about 4000 years ago in
ancient China. Other names for this game are (Chinese) Wei Chi
and (Ing) Goe
Playing a game in ASCII mode
To start a game with default options, just invoke "gnugo". The board
will be drawn at your terminal using ASCII letters. In this mode, you can get
help on available commands by the h
key. To play as Black with 4 stones
handicap, with a 0.5 komi, recording the game in the file record.sgf:
gnugo --color black --handicap 4 --komi 0.5 -o record.sgf
Playing a game with CGoban
CGoban is a general purpose client program by Bill Shubert for playing Go. It
runs under X Window System with a beautiful resizeable graphic display. To use
GNU Go under X Window System, obtain the most recent version of CGoban from
Bill Shubert's web site
Start CGoban. When the CGoban Control panel comes up, select `Go Modem.' You
will get the Go Modem Protocol Setup. Choose one (or both) of the players to
be ``Program,'' and fill out the box to the path to gnugo. After clicking OK,
you get the Game Setup window. Choose ``Rules Set'' to be Japanese (otherwise
handicaps won't work). Set the board size and handicap if you want. Click OK
and you are ready to go.
In the Go Modem Protocol Setup window, when you specify the path to GNU Go, you
can give it command line options, such as --quiet to suppress most messages.
Since the Go Modem Protocol preempts standard I/O, other messages are sent to
stderr, even if they are not error messages. These will appear in the terminal
from which you started CGoban.
The game stops when both players pass. GNU Go will attempt to compute and report
the score to you. It may occasionally make mistakes due to wrong evaluation of
the status of a group. You can check the score as follows. In ASCII mode, at
the end of the game, stones believed dead are marked in lower case letters,
and you have the option of toggling their status before counting. Using
CGoban, you may use CGoban's counting facility to count the game using either
Japanese or Chinese rules.
Viewing a stored game
filename.sgf --mode ascii
loads filename.sgf and lets you navigate through the game by using the commands
. It is not possible
to navigate through variations in ascii mode. You may also use CGoban to view
stored games. CGoban can navigate variations.
The files in the doc
directory contain detailed documentation about
debugging options and internal program structure. Other documentation may be
found in comments throughout the source code.
Go Modem Protocol
The Go Modem Protocol is a standard interface between Go programs and graphical
The Go Modem Protocol was developed by Bruce Wilcox with input from David
Fotland, Anders Kierulf and others. Any Go program *should* use this protocol
since it is standard. Since CGoban supports this protocol, the user interface
for any Go program can be done entirely through CGoban. Using the Go Modem
Protocol, you can play with another computer running a different program (even
on a different operating system) using a modem, a serial cable or over the
internet if the other program also supports the protocol. You can also
communicate with the Go servers using CGoban.
Smart Game Format
Games (with comments, variations and other features) can be stored in the Smart
Game Format (SGF). This format originated in Anders Kierulf's program Smart
Go. Martin Muller and Arno Hollosi developed the current standard, which may
be found at
GNU Go supports the Smart Game Format.
force the playing mode ( ascii'
). Default is
ASCII. If no terminal is detected GMP (Go Modem Protocol) will be assumed.
replay the game generating moves for color, where color is white
, or both
. (requires -l
Don't print copyright and other informational messages.
-l, --infile file
Load the SGF file (to score or analyze a recorded game).
-L, --until move
Stop loading just before move
is played (e.g. 154 or L10).
-o, --outfile file
Save the played game to file
in SGF format.
Set the board size to use (1-19). Default is 19, other common formats are 13 and
Choose your color ( black
). Black plays first, White gets
the komi compensation.
Set the number of handicap stones.
Set the komi (points given to white player to compensate advantage of the first
move, usually 5.5 or 0.5). Default is 5.5.
Display the version of GNU Go.
Display help message.
Display help about debugging options.
Display copyright notice.
Debugging and advanced options:
Show board each move.
Level of play. (default 10; smaller=faster, weaker).
-b, --benchmark num
Benchmarking mode - can be used with -l
Verbose tracing (use twice or more to trace reading).
-r, --seed num
Set random number seed.
Count or estimate territory of the input file. Usage:
gnugo --score estimate -l filename
Loads the SGF file and estimates the score by measuring the influence. Use with
if you want the estimate somewhere else than at the end of the file.
gnugo --score finish -l filename
Loads the SGF file and gnugo continues to play by itself up to the very end.
Then the winner is determined by counting the territory.
gnugo --score aftermath -l filename
Similar to --score finish
except that a more accurate but slower
algorithm is used to determine the final status of the groups.
If the option -o outputfilename
is provided, the results will also be
written as comment at the end of the output file.
Load SGF file, output final position (requires -l
If you find a bug, please send the SGF output file to firstname.lastname@example.org together
with a description of the bug.