Credits

Motif puzzle packs are built from the Lichess puzzle database, used under CC0.

Opening names and book moves from lichess-org/chess-openings (CC0 1.0).

The board is ours. Chess pieces by Colin M.L. Burnett (cburnett), used under the BSD license. Move rules use chess.js (BSD-2).

Copyright (c) 2006 Colin M.L. Burnett Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. 3. Neither the name of the copyright holder nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

Analysis uses Stockfish (GPL-3). Source: github.com/official-stockfish/Stockfish. The engine file is the unmodified stockfish.js package, loaded from jsDelivr.

Coach Rex is the coach in the chamber.

Artwork and sound

Streak animation: "Spiro Streak" by Patgrivet, licensed under CC BY 4.0.

The earlier fire streak and the success mark are ours. The fire uses Montserrat, licensed under the SIL Open Font License.

Gem sounds from "Interface Sounds" and "RPG Audio" by Kenney, released under CC0 1.0. Trimmed and mixed by us.