You've probably noticed the new tab in the friends panel - this is a new Apprentices feature!

This is a referral system that will allow you to bring friends and become their mentor. The higher your friend gets in levels, the higher your reward is.  

How to add an apprentice?

1. Go to the Apprentices tab at the bottom of the screen.
      
2. Click on the “Add friend” button. There you can invite the apprentice - it will give you the invitation link.
      
   
      

3. Your friend has to start the game using this link and sign up.
      

Also note that you can invite as your apprentice only those players, who didn't play the game before.

After your apprentice reaches level 7 in the game and you get all the achievements for them, they are automatically removed from your apprentices list. 

This way you can continue to invite other friends to the game who will be your new apprentices.