Terms of Use

Last updated 14 August 2026

1. Agreeing to this

Opening Punisher is operated by one person at openingpunisher.com. Using the site means you accept these terms. If you don't accept them, don't use it.

You must be at least 13 years old to create an account. Handling of your data is covered separately in the Privacy policy, which is part of these terms.

2. What the service is

Opening Punisher downloads chess games you or another player have already published on Lichess or Chess.com, runs a chess engine over the opening moves to find mistakes that went unpunished, and turns those into puzzles. It also provides an opening explorer and scoring reports built from the same games.

An account is optional. Without one you can use every feature, but nothing is saved beyond your own browser session. An account is what buys you saving across devices.

3. Your account

• Give accurate information when you sign up, and keep your sign-in credentials to yourself.
• You are responsible for what happens under your account.
• Don't share an account, and don't use somebody else's.
• You can ask for your account to be deleted at any time — see the Privacy policy.

We can suspend or remove an account that is being used to break these terms. If it is anything other than obvious abuse, you'll be told why.

4. Using it fairly

Don't do any of the following:

• Cheating. Don't use this — or any engine tool — to get help during a live game. Every chess platform bans engine assistance and will close your account for it. This site is for studying games that are already finished.
• Hammering the game platforms. The app downloads games through Lichess's and Chess.com's public interfaces, under rate limits those platforms set. Don't script it, automate it, or run bulk downloads through it. Doing so risks the access that every user of this site depends on.
• Harassment. The scouting feature reads games a player has already made public on their own account. Using it to follow, target, intimidate or harass a specific person is not allowed.
• Attacking the service. No probing, scraping, load testing, or attempting to reach data that isn't yours. No automated access of any kind without written permission.
• Reselling. Don't charge anyone for access to this site or resell what it produces as a service of your own.

5. The code is not yours to take

Opening Punisher, its design, its text and its source code belong to openingpunisher.com and are protected by copyright.

This site is built without a bundler, so its JavaScript and CSS reach your browser in readable form. That is a consequence of how it is built, not a licence. Being able to read the source in developer tools — which you are entirely welcome to do — does not grant permission to copy it, reuse it, adapt it, or ship any part of it in something else.

Not everything here is ours, and the parts that aren't keep their own terms. The chess engine is Stockfish, licensed under the GPLv3; the board widget is chessboard.js under the MIT licence; the piece artwork is a widely redistributed set originating on Wikipedia. Those components are governed by their own licences, not by this section.

6. Your data and your games

The games you download stay yours. Storing them so the app can work doesn't give us ownership of them or any right to publish them.

You're responsible for having the right to use whatever you point the app at. In practice that means public games on the platforms it reads, which is all it can reach.

7. Third-party platforms

This site is not affiliated with, endorsed by, or connected to Lichess or Chess.com. It uses their public interfaces as any other application may. Your use of those platforms is governed by their terms, not these, and if either changes or withdraws access, features here may stop working with no notice.

8. It is provided as-is

This is a free tool built and run by one person. It is provided as-is and as-available, with no warranty of any kind, express or implied, including any warranty of merchantability, fitness for a particular purpose, or non-infringement.

Specifically, nothing here promises that:

• the site is available, or stays available;
• a scan finds every mistake in your games, or that what it finds is correct — engine evaluations are estimates, and the definition of a "mistake" is a threshold somebody chose;
• the reports and scores mean anything precise about your play. They are a training aid, not a measurement;
• using it improves your rating;
• your saved data survives. Keep your own copies of anything you would miss.

9. Limits of liability

To the fullest extent the law allows, we are not liable for any indirect, incidental, special or consequential damages, or for lost data, lost time, or lost rating, arising from using this site or being unable to use it.

Where liability cannot be excluded, it is limited to the amount you have paid to use the service — which, the service being free, is nothing.

Some places don't allow these exclusions, in which case they apply to you only as far as local law permits.

10. Changes and endings

Features may change, and the service may be suspended or discontinued entirely. Reasonable notice will be given before anything shuts down for good, so that anyone with saved work has a chance to export it.

These terms may be updated. The date at the top changes when they are, and continuing to use the site after that means accepting the new version. If a change materially reduces your rights, it will be flagged in the app rather than only here.

You may stop using the site at any time; ask for account deletion and that ends the arrangement completely.

11. Odds and ends

If any part of these terms turns out to be unenforceable, the rest still stands. Not enforcing something immediately doesn't waive the right to enforce it later. These terms, with the Privacy policy, are the whole agreement between you and us about this site.