A game is rated and will affect your ratings, if all of the following conditions are met:

• The game must be started as a rated game, whether offered in the waiting room or by invitation.
  
• Both players must have a DGS rating when the game has started.

DGS rating does not mean Rank info, but the rating managed by Dragon. You can set an initial rating in your user profile. Be careful choosing your rating as it can normally not be changed once you set it and you played a rated game. If your strength changed in a big step (over 6k of rating difference), then you may ask for a rating-change following the instructions of the Change DGS-rating and rank-info page.