Terms of Service for iSudoku
Effective date: 5 August 2026 · Last updated: 5 August 2026
In short
- iSudoku is developed, owned and published by EXO TECHNOLOGIES GLOBAL LIMITED. EXO Studio is a brand operated by EXO TECHNOLOGIES GLOBAL LIMITED. It is a free Sudoku puzzle mini game played inside the TikTok / Douyin app.
- There is no account to create and nothing to buy in the game.
- Hints and continue-after-loss are earned by choosing to watch a rewarded video ad. You are never required to watch one.
- Play fairly and do not tamper with, copy, or resell the game.
- The game is provided "as is"; the TikTok app and its ads are governed by ByteDance's own terms.
1. Acceptance of these Terms
These Terms of Service ("Terms") form an agreement between you and EXO TECHNOLOGIES GLOBAL LIMITED ("the Company", "we", "us") governing your use of the iSudoku mini game ("iSudoku", "the game"). EXO Studio is a brand operated by EXO TECHNOLOGIES GLOBAL LIMITED. By opening or playing iSudoku you accept these Terms. If you do not accept them, please do not play the game.
2. The service we provide
iSudoku is a single-player Sudoku puzzle game that runs as a mini game inside the TikTok / Douyin app. It offers four difficulty levels, pencil notes, an eraser, unlimited undo, a play timer, and a mistake counter with a per-difficulty limit. The game is provided free of charge.
iSudoku runs entirely on your device. It has no servers, no accounts, no leaderboards, and no multiplayer or social features. Because the game keeps no saved data, closing the mini game ends the current puzzle and your next session starts fresh.
3. Licence to use the game
Subject to these Terms, EXO TECHNOLOGIES GLOBAL LIMITED grants you a personal, limited, non-exclusive, non-transferable, non-sublicensable, revocable licence to play iSudoku for your own private, non-commercial entertainment on a device you control.
This licence grants no ownership. All rights not expressly granted are reserved by EXO TECHNOLOGIES GLOBAL LIMITED.
4. Eligibility
You may play iSudoku only if you are permitted to use the TikTok / Douyin app under ByteDance's terms and applicable law in your country. If you are a minor in your jurisdiction, you should play only with the involvement of a parent or legal guardian, who accepts these Terms on your behalf.
5. Acceptable use
You agree not to:
- copy, modify, translate, reverse engineer, decompile, or disassemble the game, or attempt to derive its source code, except to the extent this restriction is prohibited by applicable law;
- distribute, sell, rent, lease, sublicense, or republish the game or any part of it, including its puzzle generator, artwork, or code;
- use cheats, automation, scripts, emulators, or modified clients to alter gameplay, to obtain rewards without watching an ad, or to generate fraudulent ad impressions;
- interfere with, overload, or attempt to disrupt the game, the TikTok mini game platform, or the advertising systems it uses;
- remove or obscure any copyright, trademark, or other proprietary notice; or
- use the game for any unlawful purpose.
6. Your content and your responsibilities
iSudoku has no chat, no profiles, no uploads, and no way to publish or share content with other players. The only input you provide is the numbers and notes you place in the puzzle grid, which remain on your device and are never sent to us. You therefore submit no user content to EXO TECHNOLOGIES GLOBAL LIMITED and grant us no licence over anything you create.
You are responsible for the device you play on, for your network or mobile data charges, and for keeping the TikTok app and your operating system in a supported state.
7. Rewarded advertising and in-game rewards
iSudoku shows rewarded video ads only. An ad is never forced on you: it appears only after you tap to request a hint, or choose to continue after reaching the mistake limit.
| Action | What you receive |
|---|---|
| Watch a rewarded video to the end after tapping the hint button | One hint revealed in the current puzzle |
| Watch a rewarded video to the end after reaching the mistake limit | The chance to continue the current puzzle instead of losing |
| Close the video early, or the ad fails to load | No reward is granted; the game continues normally |
Rewards are in-game features only. They have no monetary value, cannot be bought, sold, transferred, redeemed, or exchanged for anything outside the game, and expire when the session ends. Ad availability depends on the TikTok mini game platform and is not guaranteed.
8. No purchases or subscriptions
iSudoku contains no in-app purchases, no subscriptions, no virtual currency, and no payment functionality of any kind. We will never ask you for payment details inside the game. If anything in or around the game asks you to pay for iSudoku, it does not come from EXO TECHNOLOGIES GLOBAL LIMITED — please report it to us.
9. Intellectual property
iSudoku, including its source code, puzzle generation logic, interface design, layout, artwork, icon, and the name "iSudoku", is owned by EXO TECHNOLOGIES GLOBAL LIMITED and protected by copyright and other intellectual property laws. The rules of Sudoku themselves are not claimed by us.
Trademarks, logos, and service marks of ByteDance, TikTok, and Douyin belong to their respective owners and are used only to identify the platform on which the game runs.
10. Third-party services
iSudoku runs on the TikTok mini game platform operated by ByteDance, which provides the runtime, the rewarded video advertising, and the device APIs the game uses. Your use of the TikTok / Douyin app and any advertisement shown inside the game is governed by ByteDance's own terms and policies, including the TikTok Privacy Policy.
We do not control advertisements or any website or offer they lead to, and we are not responsible for their content, accuracy, or the practices of the advertisers. Dealings with an advertiser are solely between you and that advertiser.
11. Privacy
iSudoku collects no personal data and transmits nothing about you to EXO Studio. How the game handles information on your device is described in our Privacy Policy at https://exo-pages.web.app/isudoku/privacy, which forms part of these Terms.
12. Disclaimers
iSudoku is provided "as is" and "as available", without warranties of any kind, whether express, implied, or statutory, including any implied warranties of merchantability, fitness for a particular purpose, title, and non-infringement.
We do not warrant that the game will be uninterrupted, error-free, always available, or compatible with every device, or that ads will always be available when you request a reward. Some jurisdictions do not allow the exclusion of certain warranties, so parts of this section may not apply to you.
13. Limitation of liability
To the fullest extent permitted by law, EXO TECHNOLOGIES GLOBAL LIMITED will not be liable for any indirect, incidental, special, consequential, exemplary, or punitive damages, or for any loss of data, profits, goodwill, or opportunity, arising out of or related to your use of or inability to use iSudoku, even if we have been advised of the possibility of such damages.
Because iSudoku is provided free of charge and involves no payment, our total aggregate liability to you for all claims relating to the game is limited to fifty United States dollars (USD 50) or the minimum amount permitted by applicable law, whichever is greater.
Nothing in these Terms excludes or limits liability that cannot lawfully be excluded or limited, including liability for death or personal injury caused by negligence, or for fraud.
14. Indemnity
You agree to indemnify and hold EXO TECHNOLOGIES GLOBAL LIMITED harmless from any claim, demand, loss, or expense, including reasonable legal fees, arising from your breach of these Terms or your misuse of the game.
15. Termination
You may stop using iSudoku at any time by closing or removing the mini game; no further action is needed, as the game stores nothing.
We may suspend, modify, or discontinue iSudoku, in whole or in part, at any time, and may terminate your licence if you breach these Terms. Sections on intellectual property, disclaimers, limitation of liability, indemnity, and governing law survive termination.
16. Changes to these Terms
We may update these Terms when the game changes or when law or platform requirements change. The revised version will be posted at this address with a new "Last updated" date. Continuing to play after an update means you accept the revised Terms. If you do not accept them, stop using the game.
17. Governing law and disputes
These Terms are governed by the laws of the Socialist Republic of Vietnam, without regard to its conflict-of-laws rules. The courts of Hanoi, Vietnam have jurisdiction over any dispute arising from these Terms or the game.
If you are a consumer resident in another country, this does not deprive you of the protection of mandatory consumer laws of your country of residence. We encourage you to contact us first so we can try to resolve any issue informally.
18. Contact us
For any question about these Terms or about iSudoku, write to:
EXO TECHNOLOGIES GLOBAL LIMITED
Hong Kong
exostudio.feedback@gmail.com