If you're talking about the 'your wolves played..' posts people will sometimes put in chat, you do that by following the steps Ginger Mange gave you to get to pack life. This isn't the actual 'play' feature though, it's just a mini game that generates random things it tells you your wolf/wolves did.
It causes a good amount of confusion between Pack life and the true play feature, as pack life does say that they played, but pack life is very different from the play feature
However if you're talking about the actual 'play' feature, you can only use it if your account is premium.
If you are premium, you are able to play with your wolves that just finished a successful explore session.
Once one wolf has earned 25 play points, you can trade those points in for 25 CP
Spring Month: 2 
Night 
Fog Moon: 
