User Guide

💡 Core Idea: Play Silently with Eyes Closed

The core idea of this app is that you play with your eyes closed and without using your voice. Simply put on earplugs, close your eyes, control the pieces by just touching the screen-quadrants with your thumbs. The app offers a completely immersive, audio-guided blindfold chess environment.

🎮 How to Play

Starting a New Game

1. Open the App: The app starts on the Menu screen.
2. Select Boards: Choose the number of simultaneous games you wish to play (from 1 to 64).
3. Choose Your Color: In case of playing one board: select "White" or "Black" from the "Choose color" dropdown. Note: If you choose to play multiple boards, this setting is not available, and your color will alternate (White/Black) for each successive board.
4. Select Level: For beginners, there are levels "give 1", "give 2" and "give 3". Level "give 3" is the easiest: the opponent might give a knight or a bishop without a fight! The other options – for example "depth 1" and "depth 2" – directly set how many moves deep the Stockfish AI will calculate, with higher numbers indicating a stronger opponent.
5. Select Variant: Choose "Standard" for regular chess or "Chess 960" for a random starting position. The starting position will be displayed visually on the menu screen.
6. Always Promote to Queen: By default, this option is enabled, meaning your pawns will automatically promote to a Queen. Uncheck this option if you want to manually choose your promotion piece (Queen, Rook, Bishop, or Knight) during the game.
7. Mention Color: By enabling this option, you will hear "black pawn" instead of just "pawn", etc. at each move.
8. Opponent Voice: Select the voice of the opponent. If you choose voice A for the opponent, your moves will be spoken by voice B, and vice versa.
9. Start Game: Tap the "Start Game" button.

Using the Game Menu

During a game, tapping the white square in the center will open a menu with the following options:

• "Undo Last Move": Tap this to undo the last full move (your move and the AI's response). In multi-board mode, it will undo the current board's last (AI) move and then switch to the previous board to undo your last move.
• "Cancel Selection": If you've started selecting a square but want to reset, tap this button. It will clear your current partial selection. A shortcut for this (without opening the game menu, keeping your eyes closed) is to swipe from right to left over at least 25% of the screen width.
• "View PGN": When in doubt about the move history, you can see the history of all the boards you're playing in a PGN-like format and then "Resume Game".
• "Main Menu": Returns you to the main menu. Here you can review the 960 starting position and then click "Resume Game".
• "Resume Game": Returns you to your current game.

Making a Move (Square Selection)

For a video explanation, see our YouTube short.

The game screen consists of four large, touchable quadrants:

• TL (Top Left)
• TR (Top Right)
• BL (Bottom Left)
• BR (Bottom Right)

When you use the app in full-screen mode, you can use your thumbs to tap these quadrants. To select any square of the 8x8 chessboard, you will make three consecutive taps on these quadrants. Each tap narrows down the selection to a smaller quadrant, eventually pinpointing a single square. Visual help is provided during play to get acquainted with this system.

Example 1: tapping BR BL TL selects E2 (for White)

• Tap 1 (BR): Selects the bottom-right 4x4 quadrant (e1-h4).
• Tap 2 (BL): Selects the bottom-left 2x2 quadrant (e1-f2) within the previous 4x4 (e1-h4).
• Tap 3 (TL): Selects the top-left 1x1 square (e2) within the previous 2x2 (e1-f2).

(Note: The actual quadrant sequence for a specific square depends on your chosen color (White or Black) as the board is oriented from your perspective.)

Other examples:

• TR TR TR selects h8 (or a1 if you have the black pieces).
• TL BR BR selects d5 (or e4 if you have the black pieces).

Steps to Make a Move:

1. Select the "From" Square: Perform three taps to select the square of the piece you want to move.
   • The app will announce your chosen square (e.g., "White pawn from e2").
2. Select the "To" Square: Perform another three taps to select the destination square for your piece.
   • The app will announce the destination square (e.g., "to e4").
   • If the move is illegal, you will hear "That's an illegal move". The square selection is undone so that you can try again.

Promotion

If your pawn reaches the last rank and you have unchecked the "Always promote to queen" option in the menu:

1. After selecting the "to" square for your pawn's promotion, the app will announce: "Choose a promotion piece."
2. The four touchable quadrants will now display the promotion options:
   • Top Left: Queen
   • Top Right: Rook
   • Bottom Left: Bishop
   • Bottom Right: Knight
3. Tap the quadrant corresponding to the piece you wish to promote to.
   • The app will confirm your choice by finishing the move sentence with – for example – "promoted to Queen". The full sentence that you've heard, might then be: "White pawn from f7 takes g8 – choose a promotion piece – promoted to Queen".

Live streaming a game

If you are a chess streamer / content creator, feel free to use our live stream feature. Here are the steps to play on your phone and have a boards viewer on your computer!

1. On your phone, open the app. Press the title "blindfold-chess.app" three times.
2. Below the "Start Game" button, you can now see a "STREAM ID".
3. On your computer, open blindfold-chess.app/live, fill in the ID and press play.
4. On your phone, press "Start Game".
5. Your (simul) game is streamed live now! Video-record the page blindfold-chess.app/live for your viewers while you play on your phone eyes closed/blindfolded.
6. To stop streaming, go to the main menu in the app on your phone and press the title "blindfold-chess.app" another three times. Your phone then stops pushing moves to the "/live" page.

Notes: the "/live" page is not meant for direct use by your viewers. You should share a video-stream of that page to your viewers.

🧠 Tips for Blindfold Play

• Practice Coordinates: Familiarize yourself with algebraic notation (e.g., a1, h8) thoroughly.
• Look at an empty board: When just starting to learn blindfold chess, looking at an empty board makes it much easier. If you can win games that way, then start playing games with your eyes closed.
• Start simple: Begin with standard chess, 1 board, level "give 3", then gradually increase complexity.
• Verify that you remember: During each of your turns, try to remember all piece positions. Later, you may skip doing this so consciously.
• Peek in the PGN viewer: When in doubt about a piece position, use the "View PGN" button.
• Don't be afraid to Undo: Use the "Undo Last Move" button to correct mistakes, especially when learning.
• Use "Mention color": By enabling the "Mention color" setting (via the main menu), you will hear "black pawn" instead of just "pawn", etc. at each move. This may reinforce your mental representation of the pieces and be easier for learning.
• Take care of your health: Some professional players advise against playing too many boards blindfolded. Take care of your brain ❤️

Enjoy your blindfold chess journey!

📚 Frequently asked questions

Is this app free?

Yes, blindfold-chess.app is free for individual, private, non-commercial use. Also, if you are a chess teacher or online content creator, you can show how blindfold-chess.app works and/or play (an unlimited number of) games. Make sure the URL "blindfold-chess.app" is visible at least a few seconds. For using this app, parts of this app or parts of its design outside of the domain "blindfold-chess.app" you need a license. The idea of the touch-based input system, with 3 taps to select a square, is unique – a proprietary feature found exclusively on blindfold-chess.app and owned by Symbolinker (symbolinker@gmail.com). Licenses are available if you're interested in using this idea, or parts of this app, in your own application/website/etc. For more information, see the "License Agreement" section or visit blindfold-chess.app/partners.

Can I download the app?

Yes. This app is a Progressive Web App (PWA) and can be installed on your device. When you open the app in a browser and see "blindfold-chess.app" in the URL bar, then, depending on your browser (e.g. Chrome, Edge, etc.), you might see, near the URL bar or via the browser menu, an icon for installing this app on your device. After installing, the app will appear on your home screen, and you can launch it from there. If clicking on the app icon opens a regular browser tab, then only a shortcut has been placed on your home screen. Try installing the app via a different browser.

Can I use this app offline?

Yes. There are two options:

1. Install the app (see above).
2. Use the app in a browser without installing it. After clicking the "Start Game" button, all files are preloaded and then the app doesn't need access to the internet anymore.

Can I play against a human opponent?

No, not yet. You can ask your favorite chess website to become a partner. Then you might play blindfolded against a member who doesn't play blindfolded, or create a game that requires the other member to also play blindfolded.

Other questions?

For other questions, requests for improvements or partnering, feel free to e-mail to symbolinker@gmail.com.

License Agreement

This License Agreement (the "Agreement") governs your use of the Blindfold Chess App (the "App"), located at https://blindfold-chess.app, and its associated features, including but not limited to its unique touch-based input system, audio feedback, overall design, and its associated source code and development materials. By accessing or using the App, you agree to be bound by the terms of this Agreement.

1. Ownership and Copyright

The App, including its unique touch-based input system and overall design, is the proprietary intellectual property of Symbolinker (symbolinker@gmail.com) and is protected by copyright laws. All rights not expressly granted to you in this Agreement are reserved by Symbolinker.

2. Permitted Uses

2.1. Free Individual and Personal Use

You are granted a free, non-exclusive, non-transferable license to use the App for your individual and personal purposes. This includes, but is not limited to, practicing, training, and improving your blindfold chess skills. This permission extends to individuals who may earn income from professional chess activities, such as tournament play, coaching, or content creation, provided their use of the App itself remains personal and does not involve the commercial reproduction, distribution, or integration of the App's unique features into other commercial products or services.

2.2. Educational and Content Creation Use

Chess teachers, online content creators, and similar educational entities are permitted to use and showcase the App for instructional or demonstration purposes, including playing games. When doing so, the URL "blindfold-chess.app" must be visibly displayed for at least a few seconds in any content created (videos, streams, screenshots, etc.).

3. Restricted Uses

Unless explicitly granted through a separate commercial license agreement with Symbolinker, the following uses are strictly prohibited:

• Commercial Use: Any use of the App or its unique features for direct or indirect commercial gain, including but not limited to selling access to the App, incorporating it into a paid product or service, or using it for advertising purposes.
• Reproduction and Distribution: Copying, reproducing, distributing, modifying, creating derivative works of, publicly displaying, or publicly performing any part of the App, including its code, design, or unique features, outside of the blindfold-chess.app domain.
• Reverse Engineering: Attempting to decompile, reverse engineer, disassemble, or otherwise discover the source code or underlying algorithms of the App.
• Sub-licensing: Granting sub-licenses to others to use the App or any of its components.
• Use in Other Applications/Websites: Integrating the unique touch-based input system or any other proprietary elements of the App into other applications, websites, or platforms without a specific license.

4. Commercial Licensing

For any use beyond the "Permitted Uses" described in Section 2, particularly for commercial purposes or integration into other applications/websites, a separate commercial license is required. Please contact Symbolinker at symbolinker@gmail.com to inquire about licensing opportunities or visit blindfold-chess.app/partners.

5. Third-Party Licenses

The App incorporates third-party software components, each governed by their respective licenses:

• Stockfish.js: Used for the AI opponent. Its license can be found at the official Stockfish repository.
• Chess.js: Used for chess logic. Its license can be found at the chess.js repository.

Your use of the App acknowledges and abides by these third-party licenses where applicable.

6. Disclaimer of Warranties

The App is provided "as is," without warranty of any kind, express or implied, including but not limited to the warranties of merchantability, fitness for a particular purpose, and non-infringement. In no event shall Symbolinker be liable for any claim, damages, or other liability arising from your use of the App.

7. Governing Law

This Agreement shall be governed by and construed in accordance with the laws of The Netherlands, without regard to its conflict of law principles.

8. Changes to This Agreement

Symbolinker reserves the right to modify this Agreement at any time. Your continued use of the App after any such modifications constitutes your acceptance of the new terms.

For any questions regarding this License Agreement, please contact Symbolinker at symbolinker@gmail.com.