Since the plot of Risen 2 starts shortly after the events of Risen 1, I would recommend playing it if you wanna know how Risen 2 starts and Risen 1 was actually a pretty good game. But you don't have to play it since there really wasn't much of a story to Risen. If you wanna know about the first games story then I suggest reading about it at http://www.gamefaqs.com/boards/622499-risen-2-dark-waters/62683806/700102495 I hope I could help you. =)