Privacy
The minimum, and nothing more. Here is what is stored, and why.
Playing takes nothing at all
Solo games and games with friends need no account. You can use the whole site without ever leaving an address.
If you create an account
Your email address, used only to sign you in (by one-time code, there is no password), and the nickname you pick. Plus your ranked results: ELO, games played, wins.
Audience measurement
It only starts if you accepted the banner on your first visit. It is there to know which pages are read and which games are started, never to recognise you elsewhere. Declining changes nothing about the game.
Where, and for how long
Everything is hosted in Europe. Nothing is sold on, there is no advertising, and no data is handed to a third party for its own purposes.
Deleting your data
A message through "Report a problem" is enough: account, nickname and ranking go with it.