What happened?
In March 2017, the Flash game based on the Yu-Gi-Oh trading card game Dueling Network suffered a data breach . The site itself was taken offline in 2016 due to a cease-and-desist order but the forum remained online for another year. The data breach exposed usernames, IP and email addresses and passwords stored as MD5 hashes.
When did it happen?
The breach date in the public record is March 29, 2017. The record was added to the catalogue on March 30, 2020 and last updated there on March 31, 2020.
What information was reported as exposed?
- Email addresses
- IP addresses
- Passwords
- Usernames
These are incident-level categories. The record does not prove that every category was exposed for every affected person.
Who may be affected?
This record may be relevant to people who had an account or other relationship with Dueling Network or used duelingnetwork.com around March 29, 2017. A catalogue entry does not establish that every customer was affected or that every listed data category applied to each person. Compare the record with an official notice addressed to you.
What should you do?
Compare the organization, dates, and information categories with any notice you received. Use contact details you independently confirm.
Change exposed or reused passwords, begin with your email account, and turn on multi-factor authentication where available.
Treat unexpected breach follow-ups with caution. Do not use links or phone numbers in a suspicious message; contact the organization directly.
Choose actions that match the information involved. If you find signs that someone is using your identity, the Federal Trade Commission provides a personal recovery plan at IdentityTheft.gov.
Sources and review information
- Have I Been Pwned breach catalogue record ↗
- Federal Trade Commission: What To Do After a Data Breach ↗
- Federal Trade Commission: Credit Freezes and Fraud Alerts ↗
Page reviewed September 14, 2026 by the Data Breach Help Editorial Team. Catalogue details reflect the provider record and may change.