Know the tool.
Own your next move.

01Independent and unofficial

CHAINZERO is an independent fan tool. It is not produced, sponsored, endorsed, supported by, or affiliated with Konami, 4K Media, or the Yu-Gi-Oh! TCG/OCG. References to the game and its cards identify what the tool supports.

We do not issue official rulings or guarantee tournament legality. Current official rules, regional card lists, tournament policies, and event judges control. Verify the format and event requirements before playing or registering a deck.

These terms describe the current CHAINZERO website and app. “We” and “our” refer to the operator of the CHAINZERO project. You can reach us through the project contact below.

02A free pilot

You can browse the available cards, use the binder, and build and save decks locally without paying or creating an account. The current pilot has no subscription, card sales, payment collection, or active affiliate or ambassador program.

Experimental features may have request limits, supported-card restrictions, availability limits, or early-access requirements shown when you use them. Joining the early-access list is optional and does not guarantee an invitation, a response date, or unlimited feature access. Signup is for adults 18 and older and requires agreement to these terms. The browsing tool is not directed to children under 13.

Optional accounts, approved-tester access, and cloud sync are being introduced separately. Controls may appear while the live account service and sign-in email delivery are still being connected; account features apply only when enabled. Signing up for an account or requesting an invitation does not guarantee approval for restricted features. Use an email address you control and keep sign-in codes and session access private. Per-account quotas may apply to online analysis even for approved testers; the limits shown in the app govern the available pilot access.

If we later introduce paid organization or analysis features, we will present the price, features, limits, and applicable terms before asking you to purchase. Joining this pilot does not authorize a future charge.

03Experimental means check the result

Strategist and Mad Scientist use card information, supported game actions, and automated judgments to explore decks, lines, and synergies. Their coverage is limited. A supported result is not proof that every interaction, response window, or ruling has been tested.

Outputs may be incomplete, outdated, or wrong. “Needs review” is unresolved, not confirmation. Neither the characters nor their explanations represent an official judge, a human coach, or a guaranteed competitive result.

Opening-hand probabilities describe the assumptions and supported patterns shown in the tool. They do not predict your match result or establish every way a hand can succeed or fail. Prices are estimates, not offers to sell, and may omit shipping, condition, taxes, and regional availability.

Use these features as preparation aids. Check card text and current official resources, and test a proposed line before relying on it in an event or buying cards.

04Card rights and sources

Card data and images are supplied by YGOPRODeck. Yu-Gi-Oh! card names, text, artwork, symbols, and related trademarks remain the property of their respective rights holders. YGOPRODeck credits 4K Media Inc. for the card text and imagery it supplies. We do not claim ownership of those materials.

CHAINZERO’s contribution is its organization tools, interface, and experimental analysis. Free access, source attribution, or this unofficial-tool notice does not grant anyone a license to reuse third-party card material. Do not treat access to this app as permission to reproduce or commercialize that material.

External sources have their own terms and may change or become unavailable. Our catalog is a selected collection, not a promise to include every card or the latest change immediately.

05Your lists remain yours

You retain any rights you hold in original deck selections, labels, and notes you create. This does not transfer ownership of the underlying card text, artwork, or trademarks to you or to us.

When you choose a feature that sends information to our server, you permit us and the necessary service providers to process that information to provide the requested feature. If you separately choose to share an experiment, reviewers may use that record to assess the result and improve the tool as described in our Privacy Policy. We do not sell your list.

Local saves use browser storage, including local storage and IndexedDB as the updated storage is introduced. Keep an export of anything you want to preserve. Deleting a deck or clearing site data can remove your local work; changing the app’s address can also affect access to browser saves.

Optional cloud sync is off by default. When available to your approved account, enabling it lets the app synchronize later account-workspace edits automatically while online, including edits queued on the device while offline. Turning it off stops future automatic synchronization but does not remove a cloud copy already saved. Signing in does not opt you into sync or merge your guest collection. Copying the guest workspace into your account requires separate confirmation and replaces that account workspace while leaving the guest copy separate.

Review any conflict or replacement warning and keep a backup before choosing a version. Cloud saves keep the current workspace, not every past version. Signing out preserves local workspace copies; clear site data to remove them from a shared device. Request account or cloud-data deletion through an available account control or the project contact described in the Privacy Policy. Offline app-shell and artwork caching does not make account services or online analysis available without a connection.

06Use the tools responsibly

• Do not present CHAINZERO output as official Konami advice, an official ruling, or certification that a deck or line is event-legal.
• Do not bypass access controls or request limits, impersonate others, disrupt the service, or use it to infringe another person’s rights.
• Provide information you are entitled to use. Keep sensitive personal information and other people’s private information out of deck labels and feedback.
• Do not imply the Strategist characters are real people or official representatives. They are part of CHAINZERO’s presentation of its tools.

07A pilot can change

We may change limits, correct results, suspend abusive access, or pause or remove features for maintenance, cost, safety, legal, or data-source reasons. If a rights holder or source raises a concern, we may remove card art, text, or a feature while we review it.

To the extent permitted by applicable law, the pilot is provided as available, without a promise of uninterrupted access, completeness, accuracy, suitability for a particular purpose, or preservation of every save. These terms do not exclude liability that the law does not allow us to exclude.

Nothing here takes away mandatory consumer rights or prevents you from making a complaint to a regulator or seeking a remedy available under applicable law.

We will post revised terms with an updated effective date and highlight material changes on the site. Where new permission or agreement is required, we will ask for it before applying the change.

08Questions or a rights concern?

For questions about these terms, access, or a copyright or trademark concern, use the project contact below. For a rights concern, identify the material and its location, explain your connection to the rights involved, and include a way to reach you.

Personal-information requests are covered by the Privacy Policy.