These Terms of Service ("Terms") govern your access to and use of the Lucid Chess mobile application and any associated web surfaces (collectively, the "Service"), operated by Lucid Chess LLC ("we," "us," or "our"), a limited liability company formed under the laws of the State of Tennessee, United States.
By downloading, installing, or using the Service, you agree to be bound by these Terms. If you do not agree, do not use the Service.
You must be at least 13 years old to use the Service. By using the Service, you represent and warrant that you meet this requirement and that you have the legal capacity to enter into a binding agreement. If you are between 13 and 18, you represent that your parent or guardian has reviewed and agreed to these Terms on your behalf.
We do not knowingly collect personal information from children under 13. If we learn that a child under 13 has created an account, we will delete it promptly.
You must create an account to access most features of the Service. You agree to:
You may not create accounts using automated methods, or create more than one account per person for the purpose of gaming the rating system or earning free virtual goods.
Subject to your compliance with these Terms, we grant you a limited, non-exclusive, non-transferable, revocable license to download and use the Service on your personal device(s) solely for your own personal, non-commercial chess training purposes.
You may not sublicense, sell, resell, transfer, assign, or commercially exploit any portion of the Service.
Certain features of the Service require a paid subscription ("Lucid Chess Pro"). Free users retain access to all Core Skills content and a limited free-trial session for each premium training mode. Subscribed users have unrestricted access to all premium modes, Daily Path, Blind Tactics, Double Blind, and other gated content.
Subscriptions are available on monthly and annual terms. Payment is processed through the platform you use to subscribe:
| Platform | Payment Processor | Refund Policy |
|---|---|---|
| iOS (App Store) | Apple Inc. | Apple's standard refund policy applies. Request refunds via reportaproblem.apple.com. |
| Android (Google Play) | Google LLC | Google's standard refund policy applies. Request refunds via the Google Play app or order history. |
| Web | Stripe, Inc. | Contact us at [email protected] within 14 days of charge. Refunds are issued at our discretion. |
Subscriptions auto-renew at the end of each billing period unless cancelled before the renewal date. The renewal charge is processed through the same platform you originally subscribed through.
You may cancel your subscription at any time through your platform's subscription management settings. Cancellation takes effect at the end of the current billing period — access is not terminated early and no pro-rated refunds are issued for the remaining period.
We reserve the right to change subscription prices. We will provide advance notice of price changes through in-app notification or the email associated with your account. Continued use after a price change takes effect constitutes acceptance of the new price.
The Service offers one-time in-app purchases, including:
All one-time purchases are processed through Apple (iOS), Google (Android), or Stripe (web) and are non-refundable except as required by applicable law or as determined by the relevant platform.
Keys, Lucidity (both purchased and earned), and the Blind Rating (BR) are virtual, in-app constructs with no monetary value. They cannot be redeemed for real money, transferred outside the app, or exchanged for any goods or services. No refund, cash-out, or conversion to real currency is available under any circumstances.
Lucidity earned through gameplay (as opposed to purchased) is complimentary in-app content. It carries no monetary value and is not a purchase of any kind.
Keys and Lucidity are stored in your account and do not expire as long as your account remains active. If your account is terminated for a violation of these Terms, any unused virtual goods are forfeited without compensation.
The Blind Rating ("BR") is a skill metric proprietary to Lucid Chess that measures chess visualization ability. It is computed from your performance in premium training modes and Play vs. Bots using the Glicko-2 algorithm adapted for visualization assessment.
The BR is an in-app measurement tool only. It has no monetary value, is not transferable, and is not a credential recognized by any chess governing body. We reserve the right to recalibrate the BR algorithm — including retroactive adjustments to ratings — when doing so improves measurement accuracy. We will communicate material rating recalibrations in advance.
You agree not to:
We reserve the right to investigate suspected violations and to take appropriate action, including suspending or terminating accounts without advance notice.
The Service and all of its content — including but not limited to software, design, visual aesthetics, puzzle databases, bot personalities, game analysis, the Blind Rating system, and the "Immortal Path" feature — are owned by Lucid Chess LLC or its licensors and are protected by copyright, trademark, and other intellectual property laws.
"Lucid Chess" is a trademark of Lucid Chess LLC. You may not use our name, logo, or trademarks without our prior written consent.
You retain ownership of any personal data you provide (such as your username and chess rating). By providing this data, you grant us a limited license to use it to operate the Service as described in our Privacy Policy.
Nothing in these Terms transfers any intellectual property rights to you. The license granted in §3 is the full extent of your rights in the Service.
Our collection and use of your personal information is governed by our Privacy Policy, which is incorporated into these Terms by reference. By using the Service, you agree to our data practices as described there.
THE SERVICE IS PROVIDED "AS IS" AND "AS AVAILABLE," WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE, AND NON-INFRINGEMENT.
We do not warrant that: (a) the Service will be uninterrupted, error-free, or secure; (b) any defects will be corrected; (c) the Service is free of viruses or harmful components; or (d) use of the Service will improve your chess performance. Chess skill improvement depends on many factors outside our control.
Some jurisdictions do not allow the disclaimer of implied warranties. To the extent such warranties cannot be disclaimed under applicable law, they are limited in duration to 90 days.
TO THE MAXIMUM EXTENT PERMITTED BY APPLICABLE LAW, LUCID CHESS LLC AND ITS MEMBERS, OFFICERS, EMPLOYEES, AGENTS, AND LICENSORS SHALL NOT BE LIABLE FOR ANY INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL, PUNITIVE, OR EXEMPLARY DAMAGES, INCLUDING BUT NOT LIMITED TO LOSS OF PROFITS, DATA, GOODWILL, OR OTHER INTANGIBLE LOSSES, ARISING OUT OF OR IN CONNECTION WITH THESE TERMS OR YOUR USE OF (OR INABILITY TO USE) THE SERVICE.
IN NO EVENT SHALL OUR TOTAL CUMULATIVE LIABILITY TO YOU FOR ALL CLAIMS ARISING OUT OF OR RELATED TO THESE TERMS OR THE SERVICE EXCEED THE GREATER OF: (A) THE TOTAL AMOUNT YOU PAID TO US IN THE 12 MONTHS PRECEDING THE CLAIM, OR (B) FIFTY U.S. DOLLARS ($50).
Some jurisdictions do not allow certain limitations of liability. In those jurisdictions, our liability is limited to the greatest extent permitted by law.
You agree to indemnify, defend, and hold harmless Lucid Chess LLC and its members, officers, employees, agents, and licensors from and against any claims, liabilities, damages, losses, and expenses (including reasonable attorneys' fees) arising out of or in any way connected to: (a) your access to or use of the Service; (b) your violation of these Terms; or (c) your violation of any third-party right, including any intellectual property or privacy right.
By you: You may stop using the Service and delete your account at any time. Account deletion is handled through the in-app profile settings. Deletion terminates your license to use the Service and forfeits any unused virtual goods.
By us: We may suspend or terminate your account and access to the Service at any time, with or without notice, if we reasonably believe you have violated these Terms or if we discontinue the Service.
Termination does not relieve you of any payment obligations incurred prior to termination. Sections 6, 8, 10, 11, 12, 14, and 15 survive termination.
These Terms are governed by the laws of the State of Tennessee, United States, without regard to its conflict-of-law provisions. The United Nations Convention on Contracts for the International Sale of Goods does not apply.
Before initiating any formal dispute process, you agree to contact us at [email protected] and give us 30 days to attempt to resolve the issue informally. Most issues can be resolved this way — we'd rather just fix it.
If a dispute cannot be resolved informally, you and Lucid Chess LLC consent to the exclusive jurisdiction and venue of the state and federal courts located in the State of Tennessee for any legal action arising out of or relating to these Terms or your use of the Service, and you waive any objection to such jurisdiction or venue.
To the fullest extent permitted by law, you waive the right to participate in a class-action lawsuit or class-wide arbitration against Lucid Chess LLC.
We may update these Terms from time to time. When we make material changes, we will update the "Last updated" date at the top of this page and, for significant changes, notify you in-app or via the email associated with your account.
Your continued use of the Service after an update constitutes acceptance of the revised Terms. If you do not agree to the revised Terms, you must stop using the Service.
These Terms, together with our Privacy Policy, constitute the entire agreement between you and Lucid Chess LLC with respect to the Service and supersede all prior agreements and understandings.
If any provision of these Terms is found to be invalid or unenforceable, that provision will be limited or eliminated to the minimum extent necessary, and the remaining provisions will remain in full force and effect.
Our failure to enforce any right or provision of these Terms is not a waiver of that right or provision. Any waiver must be in writing and signed by an authorized representative of Lucid Chess LLC.
You may not assign your rights or obligations under these Terms without our prior written consent. We may assign our rights to any successor or acquirer of all or substantially all of our business.
Lucid Chess LLC
[email protected]
For account deletion requests, in-app purchase disputes, or privacy rights requests, please include the relevant subject line (e.g. "Account Deletion," "Privacy Request," "Refund Dispute") so we can route your message promptly.