gnuchess

GNU Chess engine

TLDR

Start an interactive chess game

$ gnuchess

Play in two-player mode (user vs user)

$ gnuchess -u

Play in easy mode (no pondering)

$ gnuchess -e

Load a game from a PGN file

$ gnuchess -l [game.pgn]

Set search depth level

$ gnuchess -S [5]

Run as UCI engine

$ gnuchess --uci

Run as XBoard engine

$ gnuchess --xboard

gnuchess is a free chess-playing program that can be used as a standalone interactive chess game or as a backend engine for graphical chess frontends like XBoard or GNOME Chess. It supports both the XBoard and UCI communication protocols.In interactive mode, enter moves in algebraic notation (e.g. e2e4, Nf3). Type help for a list of commands. The engine includes an opening book and uses alpha-beta search with iterative deepening.

PARAMETERS

-h, --help

Display usage help.

-v, --version

Display version information.

-u

Two-player mode (user vs user).

-e

Easy mode. The engine does not think during the opponent's turn.

-l PGNFILE, --load PGNFILE

Load game from a PGN file.

-S LEVEL, --setlevel LEVEL

Set search depth level (1-10).

--xboard, -x

XBoard/WinBoard engine protocol mode.

--uci

UCI engine protocol mode.

--post, -p

Show engine thinking output.

--manual, -m

Manual mode. The engine does not play until told to.

-M SIZE, --memory SIZE

Set hash table memory size in MB.

PREVIEW

 r n b q k b n r
 p p p p p p p p
 . . . . . . . .
 . . . . . . . .
 P P P P P P P P
 R N B Q K B N R

CAVEATS

The default opening book may not be installed on all systems. Engine strength depends on the search depth and available memory for hash tables.

HISTORY

GNU Chess was first written by Stuart Cracraft in 1984, making it one of the earliest programs in the GNU Project. It has been maintained by numerous contributors over the decades and remains one of the most well-known free software chess engines.