Frequently Asked Questions

I found a bug. How do I report it?

Thanks! There's three ways to send me a bug report. Starting with the easiest:

1) Automatic Bug Reports

If you see this icon in the bottom left corner then a bug report was probably already automatically sent to me:

2) Terminal

You can use the terminal if you don't see that red icon or if you want to include more information. Go to the main menu, click "Options", then click this button:

In the terminal write the command and your message between double quotes:

bug report ""

for example:

bug report "Hello! My ranged attackers are able to capture iron pieces, like in my shared board ABC4. I expected the iron pieces to be invincible."

then press enter. This will automatically send me a lot of important system information and history.

3) Email

You can also send me a detailed email:

For emails you must include your ChessCraft version, like "1.16.23". You might also include the long debug log from clicking this button:

I have an awesome idea! How do I tell you about it?

Great! Send me an email:

or mention it in the Discord chat channel for feature ideas. Then sign up for the Frame of Mind newsletter to stay up to date on ChessCraft updates and releases.

ChessCraft will probably always be a 2D, two player, turn based, perfect information, deterministic game. Features that violate that are less likely to be implemented. It's also important that the AI can play all designs reasonably well, so that rules out features with heavy impacts on combinatorics like:

pieces that teleport or cast spells anywhere
pieces that create new pieces anywhere
pieces that move multiple times in one turn

Can you add an "undo" button?

Lots of people have asked for this! I understand that a lot of chess apps have this feature, and sometimes you genuinely make a mistake tapping the wrong move. This has happened to me too and it's always a bummer.

However, my intuition also tells me this spoils the game. The emotion and intensity you feel when you tap the wrong move swings the other way - you also feel great and accomplished when you lock in a great move. The reason you want an undo button is because you care about the state of the game. You care because it is real, locked in, and must be earned.

I'm not sure if I'll ever make an undo button. Maybe the button visibility could be optional and cannot be turned on during gameplay. I'm thinking about it. For now the answer is a soft no.

How do I report inappropriate content?

If you find user generated content on this website which you think is inappropriate or violates the Terms of Use or Content Policy please let us know:

How do I report copyrighted content?

If you own the copyright to user generated content on this website but did not authorize its use, please let us know:

Frame of Mind Games is also a registered DMCA designated agent with the US copyright office.

How does your AI work?

I've written a page describing the computer science of the ChessCraft AI.

Is this really the world's largest database of chess variants?

I think so. Currently there are over 260,000 community uploads:

nearly 68,000 variant boards
over 190,000 variant pieces
nearly 2,000 variant garbs (images)

There are other notable resources like chessvariants.com but that has just a few thousand variants. Compared to ChessCraft, on average those variants are better curated with fewer duplicates. They also have a larger variety of rules because unlike ChessCraft, usually no software or computer opponent can play those variants. It's just a text page.

One day I hope to use AI (like an LLM) to do an analysis of the human-readable chessvariants.com variants compared to the machine-readable ChessCraft variants. We could see overlaps, duplicates, popular features, how much chessvariants.com variants are supported by ChessCraft, etc. Stay tuned!

Do you know of any other large databases of machine-readable chess variants? I'd love to know!

Is there a newsletter archive?

Yes. See my blog under the ChessCraft category.

Can you fix the translations?

Please help improve ChessCraft translations by emailing me any corrections:

or mention it in the Discord chat channel for translation corrections.

The low cost ChessCraft translation system uses a combination of Google Translate and community-led translation help.

I tried to reach as many people as possible by supporting many languages, but with no budget. Quantity over quality. Hopefully it's good enough to be useful! It's also worth noting that you can choose your language in the options menu.

Can you add this translation language?

Maybe! Here's the big factors when I consider adding a language:

Popularity. The total number of speakers for your language should be high.
Google Translate. Your language must be available on Google Translate. That's because I'm constantly adding more pieces of text, and I need a way to do that without asking you for more translations every week, for years.
Platform. The Google Play and Steam distribution platforms should be popular in countries that tend to speak that language.
Unilingual. I want to make it easy for everyone to play ChessCraft. However if a culture tends to know many languages, they may not need a translation as much.

What is the translation spreadsheet?

So you want to help? Thanks! If you want to add a new language or proofread an existing language, I may share a "translation spreadsheet" with you. Here's how that works:

ChessCraft has a surprising amount of text. Over 500 different words or sentences! You don't need to review everything to be helpful. Every little bit helps.
Each row is a different piece of text, translated into all languages.
You may see special tokens like {0} or '{2}'. ChessCraft inserts text into these places as you play the game. You can change the order of the tokens, but every language in one row must have the exact same tokens.
You may see a special character \n. ChessCraft replaces this with a newline, or "enter" character. You should try to use similar newlines in any translations. On a keyboard, the \ character is usually found next to your "enter" key.
If you're not sure about the context of some text, you can look at the "key", "sort", or "en" (English) columns for context.
I must receive your changes as a spreadsheet in the same ods spreadsheet file format. You can open this with typical office software, though I highly recommend the free and open source LibreOffice Calc.
If you see fr in the "verified" column, it means that a human "may" have already proofread it ("fr" is French). If you don't, a human definitely has not seen it before. So a great place to start is looking at the rows where your language has never been proofread.

My apologies if this seems like a lot, but I do not have the time to accept random help unless it's structured.

Can you add nightriders?

This is a popular request.

A nightrider is a popular chess variant piece that can move any number of steps as a knight in the same direction.

The biggest reason I've not added nightriders yet is because I don't know how to fit it into the GUI of the piece editor, unless it's "just" exactly a nightrider and nothing slightly different. There are 8 directions a nightrider moves, maybe people just want some of those, or three steps instead of unlimited, etc. If you can doodle a nice looking GUI and email it to me, I will consider it!

How do I get in the credits?

I want to show my appreciation for everyone who helps make ChessCraft better. If you help, just ask, and I can include your name or username in the credits! But what kind of help qualifies?

You are the first to find a bug that I confirm and fix.
You help me fix my translations.
You share new piece images that I include in the game, which exactly match the size, format, and style of the other ChessCraft files.
Any other help of equal significance.

Beta testing?

If you want to be an open beta tester on Google Play, you can join on the store page.

If you want to become an iPhone open beta tester, send me an email:

There is currently no beta testing on Steam.

What is the red icon in the bottom left corner?

One of the worst kinds of bugs is called an "exception". Diagnosing an exception can be confusing because it makes all kinds of seemingly random and wacky things happen. When this icon appears, it tells us what type of bug has happened which is very useful to me. This also means your phone probably automatically uploaded detailed debug info to my server. Neat!

If you ever see this, it's a good idea to restart the game.

Can you add my art?

Maybe! Lots of people from the ChessCraft community have added their piece images to the game. See the #fan-art chat channel. However not all art makes it into the game. Here's some hard rules and soft guidelines:

Style. The main style reference is the classic chess pieces from lichess. Your pieces should match that style. Black should not simply be an inverted white.
Format. They must be 512 by 512 pixels, PNG, with an alpha/transparent background. Both white and black. I can (but won't) fix your images.
Genre. The concept should be fantasy, or medieval and earlier. Generally, no modern era or science fiction.
Zen. Avoid aggressive concepts like bombs, torture, poison, or guns.
Easy. Make it easy for me to examine and import your images. Use a zip, and name the files like w-bishop.png and b-bishop.png.
Worldly. The concept should appeal to many cultures. Avoid too much imagery of one religion, or one nation.

Does your idea not fit these rules? Share it anyway on #fan-art!

I recommend the free GIMP editor to make your images.

If your art is added to the game, send me your name or username and I'll add you to the game credits!

Finally, all art in the game is shared here under a Creative Commons license. For your art to be added to the game, you must agree to the same free and open license.

Is ChessCraft open source?

No. I would like to share the code but here are two concerns of mine:

A quote from @cra: Running a successful open source project is just Good Will Hunting in reverse, where you start out as a respected genius and end up being a janitor who gets into fights.
Knock-offs. Even with a non-commercial open source license, a low-effort app factory could reskin ChessCraft with ads and probably do fairly well with it. A non-commercial license doesn't stop people from commercial activity, it just means I can get a lawyer and win. But the money I'd win back after a year of pain probably won't even cover what I paid the lawyer.

If you're especially curious about how a specific part of the computer code works, feel free to send me an email and we can figure something out:

ChessCraft started as a fun hobby project and I want to mostly keep it that way. I'm already doing more paperwork than I want keeping up with Google Play and Steam.

May I use your art?

Yep! I've released the art for ChessCraft under a Creative Commons license. If you see art in ChessCraft that is not in that repository, let me know and I'll add it.

Do you have a Patreon?

Nope! There is no official ChessCraft Patreon. Instead, when you support the ongoing development of ChessCraft by becoming a "patron", it's simply a badge of honor in game that turns off the interruptions.

What future features are you going to add?

I prefer not to talk about my future dreams for a project. What happens is I get enjoyment out of talking about what I "will" do, but without actually doing it. Then if I ever finish the work, I get less enjoyment because I already talked about it. In this way I'd be stealing enjoyment from my future self!

Why isn't iPhone free to play?

The first release on Google Play was barely a game so it was free. Later the patron IAP donation option was added.

It was free and easy to release these first versions of ChessCraft on Google Play for Android. This started as just a fun little hobby project so I'm grateful to Google for helping me get started.

That's not the case with Apple. I researched publishing options like buying expensive hardware, cloud credits, or hacking together an emulator. I decided to buy hardware (Mac Mini M2) for long term stability and to save myself some time. I also must pay an expensive App Store developer yearly fee.

I'm hoping the iOS purchase price can quickly recover the time and money I put into the iOS release by leaching off the free marketing done by the free Android release. Maybe in the future I can do a patron style in-app-purchase, but for the moment, I feel a bit spiteful and want to make iOS users pay an extra luxury tax for choosing a closed developer ecosystem.

However, helping learners is a priority here so if you're a parent, student, or kid send me an email to ask for a free promo code for iOS:

Will there be a Mac release?

I have a long to-do list of great ChessCraft work that has a higher priority than this. Let me know if you want a desktop Mac release (laptop, desktop, mac mini) and I will prioritize it more.

See also "Will there be an iPhone (iOS) release?"

Why is there a maximum of 26 piece types on one board?

Internally the game saves its boards in a format called ChessCraft Notation (CCN). You can see an example here, or if you click "CCN" on any board page. Each piece is assigned a letter of the alphabet, where white is uppercase, and there are 26 letters. There are many ways I might increase this maximum but it is low on my list of feature ideas. 26 is a lot!

How much time did you put into this?

It's hard to say. I spent a lot of time just thinking about AI, reading AI code, and thinking about design before I started actually creating the game in January 2018.

If we don't count that: the design, art, marketing, and programming up to version 1.10 has taken maybe 2000 hours.

Do you expect to make lots of money selling this game?

No. I made this game because I wanted to play it! If making money was my goal the game would have ads and I would have released on all major platforms much earlier. In fact, if making money was my goal I don't think I would have started ChessCraft at all. The market for chess apps is hugely oversaturated.

What is Patronware?

Patronware is software that is free, complete, and ad-free. People feel good about donating money to the project. The project is not supported by dark patterns and harmful psychology.

ChessCraft tries to be patronware. I hope you agree. You can read more about this here.

One exception is the Apple store. Because of the money and time investment Apple required of me compared to Google and Valve, I decided to charge money upfront for the iPhone release.

Will there ever be ads?

ChessCraft will never have ads. I have strong feelings about this.

Why are some boards hard, and some boards easy?

The difficulty of a board is a combination of two factors:

AI complexity. This is a measure of how hard it is for the computer to think about a board. The computer has a hard time thinking about boards with lots of tiles, with many powerful pieces, and turns with many possibilities.
Human complexity. This is a measure of how hard it is for a human to think about a board. Humans have a hard time thinking about strangely shaped boards, with many different types of custom pieces, pieces that move asymmetrically, and especially pieces that move unlike any classic chess piece.

So the hardest boards for a human to play are tiny boards, with weak, all custom pieces. As of version 1.3, the board and piece editors give you a preview of the estimated AI complexity and human complexity:

Can I make a piece move like a knight "L" but without hopping?

No. What's tricky about "L without hopping" is people think of the knight movement in at least three different ways:

2 up, 1 right
1 right, 2 up
1 up, 1 diagonal up-right

So the idea of this movement being blocked like a bishop slide or rook slide is not clear.

How good is your AI?

This varies a lot depending on the board size, pieces rules, and phone speed. I'm still considering how to measure and standardize the computer difficulties. The AI is also not tuned to play classic chess, so it's at a big disadvantage compared to other classic chess AI engines. ChessCraft sees classic chess just like any other chess variant.

There is no ELO system for ChessCraft variants, so here's three pieces of information that should help you triangulate an answer.

I have a rating of 2100 on lichess puzzles and if I had an ELO it might be somewhere around 1400. If I play fast, my AI sometimes beats me. If I play a smaller board like a 6x6 I often lose.
In 2023 a community member (Popo) played ChessCraft moves against the chess.com AI at different ELOs. They estimate ChessCraft is 1300 ELO.
With a couple seconds of thinking on an average smartphone, the AI will correctly answer 24 of the 76 chess IQ puzzles on elometer.net.
I sometimes run a ChessCraft bot on lichess.org. However the score it has there is just from classic chess.

There are still a lot of improvements I could make to the AI. Read about the latest improvements in the newsletter!

What inspired you to make ChessCraft?

In 2018 I had a ludicrously bad commute to work and was looking for stuff to do. I tried lots of chess apps, and some variant apps, and I was generally disappointed by what was out there. I found some fun apps that did horde chess but I wanted to also play similar variants of it.

Chesscraft seemed like a pretty obvious game design to me and I was surprised that apparently nobody had made a game like this yet. I also dislike almost all mobile games and the mobile games industry, IAP, ads... so I really didn't feel like I had a lot of mobile game options.

Once I started thinking about the unique challenges of making an AI for this I got excited, because I like computer science. I knew before I started that I could make a decent AI, but I wanted to know how good it could become.

Who made ChessCraft?

I'm amused when people try to contact the "chesscraft team" or the "devs". Excluding community contributions for testing and translations, ChessCraft is designed and developed entirely by Stuart Spence. If you're interested in joining the team see the jobs page.