This is a game that is designed to make people happy. All you should do is doing a favour to someone that you don't know and you should not let them know you, it has to be secret. Only thing you will leave behind will be UnknownFavour(UF) Card. You may download sample PDF or Word document here. Aside from that, have fun with it and make people happy :)

If someone did you a favour - something small but makes you happy, and istead of pay it back, you paid it forward to three people. And the next day, they each paid it forward to three people...

And the day after that, those 9 people each paid it forward to another three.And each day, everyone in turn paid it forward to three people.And in two weeks, it reaches 4.782.968 people, that means 4.782.968 happy people...