Check the link, but it is pretty simple. Just add the days of wonder online facebook app. Then link your facebook account with their online service. Then play one of their games on Days Of Wonder Online, and post a story about it on your facebook account, and you could win a free board game.
The contest goes on for about 2 more weeks, and you can enter as many times as you like. so get on there now.
Full disclosure, I won a free game on the first day of the contest! Now, I know what you are thinking… But I have to assume that the contest isn’t rigged, since my facebook account doesn’t mention that I am, in fact, the world famous internet mogul, Sci-Guy-Jim.