Basically is a CCG online, you can play a LOT and get enough free "Clintz" to buy other cards, the more you play the better cards you can get, the more you win, the more you earn, the better the cards you can get ... and so forth.
If you are loaded with cash though, you can ofc buy decks with real money.
HOWEVER, you get a starter deck for free, and can play for free ... so at least give it a go.
LINK : Urban Rivals

