The General Data Protection Regulation - or GDPR - is a set of European regulations introduced by the European Union to protect online information and privacy. Adopted in April 2016, the GDPR is designed to protect online information and privacy by granting citizens and residents of the EU more control over their personal data. These regulations went into effect May 25th, 2018.
In order to comply with these regulations, Kongregate will be requiring age verification for many new and existing EU users between the ages of 13 and 16. This will occur on a per-country basis, depending on the age requirements of the country where the player lives. Access to Kongregate.com for these users will require parental permission.
You can read more about GDPR at https://www.eugdpr.org/