🏆 [#1 Chess Assistant] A.C.A.S (Advanced Chess Assistance System)

HKR
2023-01-30T14:41:33Z

Enhance your chess performance with a cutting-edge real-time move analysis and strategy assistance system

We reached 50 000 installs! Thank you for using A.C.A.S! ❤️🎉 (31/01/2026)

A.C.A.S (Advanced Chess Assistance System)

A.C.A.S is an advanced chess assistance system which enhances your chess performance with cutting-edge real-time move analysis. Just install the userscript, open the A.C.A.S site, press the "Open A.C.A.S" button and you're good to go! No downloading needed. Note that we do not advocate using A.C.A.S against human players!

Why should I prefer A.C.A.S over other similar userscripts?

Many built in WebAssembly engines (faster than JS)

External engines (via an installable localhost server)

Supports top chess sites (chess.com, lichess.org, etc.)

Multiple suggestions, arrows, variants, fonts

Multi-engine support, each with own settings

Ability to modify any engine UCI options (e.g. ELO, depth, multiPV, skill)

Visual board metrics (safe, contested, enemy squares, captured pieces)

Move feedback and opponent predictions

Render directly on external boards (or stay hidden via ghost mode)

Audio TTS suggestions with adjustable speed

Floating panel for stability and faster calculation

Customizable themes (colors, fonts, textures)

Chess variants supported (chess960, Fairy Stockfish variants)

Translated into 30+ languages

No anti-features on userscript

Impossible to detect (well, you can never be sure, so let's say it's almost impossible)

Top priority to be easy to install and use

Support developers who value quality over quantity and aren't doing shady practices

If you found a userscript that has more features and doesn't have anti-features, that's great, you should use it instead of A.C.A.S! This message is against developers stealing code and making cheap copies of existing scripts to fill them with ads and to profit from users. It's absolutely disgusting behaviour and takes away from all of us. Please always prefer userscripts without any anti-features, otherwise it will just encourage more and more developers to use anti-features.

Fundamental Idea

A.C.A.S (Tab #1) | Chess Website (Tab #2)
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The engine runs on a completely different tab than the chess game page, completely isolated from it. The site cannot block the usage of A.C.A.S. | A.C.A.S sends move data via CommLink and the userscript displays the data on the board using UniversalBoardDrawer. (If "Display Moves On External Site" setting is activated!)

IMPORTANT!

You need to keep the A.C.A.S GUI tab active to keep the whole system functional. Think of the tab as an engine of a car, the userscript alone is simply an empty hull, it won't run, nor move. The A.C.A.S GUI has the chess engine which calculates the moves.

您需要保持A.C.A.S GUI选项卡处于活动状态，以保持整个系统正常运行。可以将该选项卡视为汽车的引擎，仅有用户脚本本身就只是一个空壳，无法运行也无法移动。A.C.A.S GUI包含了计算棋局的棋类引擎。

تحتاج إلى الاحتفاظ بعلامة تبويب A.C.A.S GUI نشطة للحفاظ على عمل النظام بأكمله. فكر في علامة التبويب كمحرك سيارة ، البرنامج النصي المستخدم بمفرده هو مجرد هيكل فارغ ، لن يعمل ولا يتحرك. A.C.A.S GUI يحتوي على محرك الشطرنج الذي يقوم بحساب الحركات.

पूरी प्रणाली को कार्यरत रखने के लिए आपको A.C.A.S GUI टैब को सक्रिय रखना आवश्यक है। यह टैब एक कार के इंजन की तरह है, उपयोगकर्ता स्क्रिप्ट स्वतः में केवल एक खाली शेल है, यह नहीं चलेगा और नहीं चलेगा। A.C.A.S GUI में शतरंज इंजन है जो चालें गणित करता है।

Arrow Meaning

Color | Meaning
🟩 | Best Move
🟦 | Secondary Move
🟥 | Enemy Move

Note Enemy move is shown if "Display Opponent Move Guess" setting is activated and the square an arrow starts from is hovered. The enemy move arrow is just a guess made by the engine and means that the engine thinks after you make the move the arrow suggests, the enemy will make the move the enemy arrow suggests.

Q&A

Why did I get banned, wasn't this impossible to detect?

Chess engines simply play differently than humans. It's fairly easy to detect by pure statistics. For example, chess.com bans about 16 000 players for fair play abuse each month.

Your ban most likely wasn't because of the site detecting A.C.A.S, it was because of your suspicious behaviour patterns. A.C.A.S cannot fix this, it's your responsiblity to play as a human.

Don't want to get banned again? Don't use A.C.A.S against other humans.

Why doesn't it work?

Before making an issue, please read these,

Make sure the A.C.A.S GUI is active. Do not close the tab. Browsers freeze code execution on inactive pages, you need to visit the A.C.A.S GUI tab from time to time or keep it open on a separate window. This prevents A.C.A.S from freezing and not giving any move suggestions, for example.

Do you not see any moves displayed on the chess site? Are you sure you have enabled "Display Moves On External Site" box on the A.C.A.S GUI settings? After enabling that setting, please refresh the chess site to see changes.

Are you trying to play variants on Chess.com? If so, it's not currently supported very well since I had to rush the project, sorry! Other sites with variants might also be buggy, you can make an issue about that if you want.

Otherwise, it could be a bug, please make an issue here.

Note When making an issue, please be descriptive! Mention,

The chess site and the variant you were playing.

The browser and the userscript manager you were using.

What did you do for the bug to happen, does it happen often? How could I reproduce it?

You can also include a screenshot of the browser console (e.g. CTRL + SHIFT + I or right click, inspect, and go to the console tab), look for grey underlined text at the beginning of a red background area, on the right side of the screen, which has the word 'A.C.A.S'. That's an error from the userscript.