Trollfish is a free, entertaining, and unique UCI chess engine derived from Stockfish. It's been humorously tweaked to prioritize drawing games over winning. When analyzing chess positions, it computes moves that have the best chance of leading to a draw, rather than the optimal winning moves. This makes for a novel and amusing chess experience!
Like its predecessor, Trollfish does not include a graphical user interface (GUI) that is needed to display a chessboard and to facilitate move inputs. These GUIs are developed independently from Trollfish and can be found online. Consult the documentation for your GUI of choice for instructions on how to use Trollfish with it.
Bear in mind that Trollfish is intended as a lighthearted joke and is not designed for serious competitive play. It's perfect for players looking for a fun diversion from traditional chess engines.
Check out the Trollfish documentation for further usage help and enjoy the hilarity of striving for a draw with every move!
This distribution of Stockfish consists of the following files:
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README.md, the file you are currently reading.
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Copying.txt, a text file containing the GNU General Public License version 3.
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AUTHORS, a text file with the list of authors for the project.
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src, a subdirectory containing the full source code, including a Makefile that can be used to compile Stockfish on Unix-like systems.
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a file with the .nnue extension, storing the neural network for the NNUE evaluation. Binary distributions will have this file embedded.
The Universal Chess Interface (UCI) is a standard text-based protocol used to communicate with a chess engine and is the recommended way to do so for typical graphical user interfaces (GUI) or chess tools. Stockfish implements the majority of its options.
Developers can see the default values for the UCI options available in Stockfish
by typing ./stockfish uci in a terminal, but most users should typically use a
chess GUI to interact with Stockfish.
For more information on UCI or debug commands, see our documentation.
Stockfish has support for 32 or 64-bit CPUs, certain hardware instructions, big-endian machines such as Power PC, and other platforms.
On Unix-like systems, it should be easy to compile Stockfish directly from the
source code with the included Makefile in the folder src. In general, it is
recommended to run make help to see a list of make targets with corresponding
descriptions.
cd src
make -j build ARCH=x86-64-modern
Detailed compilation instructions for all platforms can be found in our documentation.
Improving Stockfish requires a massive amount of testing. You can donate your hardware resources by installing the Fishtest Worker and viewing the current tests on Fishtest.
In the chessprogramming wiki, many techniques used in Stockfish are explained with a lot of background information. The section on Stockfish describes many features and techniques used by Stockfish. However, it is generic rather than focused on Stockfish's precise implementation.
The engine testing is done on Fishtest. If you want to help improve Stockfish, please read this guideline first, where the basics of Stockfish development are explained.
Discussions about Stockfish take place these days mainly in the Stockfish Discord server. This is also the best place to ask questions about the codebase and how to improve it.
Stockfish is free and distributed under the GNU General Public License version 3 (GPL v3). Essentially, this means you are free to do almost exactly what you want with the program, including distributing it among your friends, making it available for download from your website, selling it (either by itself or as part of some bigger software package), or using it as the starting point for a software project of your own.
The only real limitation is that whenever you distribute Stockfish in some way, you MUST always include the license and the full source code (or a pointer to where the source code can be found) to generate the exact binary you are distributing. If you make any changes to the source code, these changes must also be made available under GPL v3.