Already back in 2007 somebody calling himself aplusbar posted a video on YouTube which was supposed to be the trailer of a film based on Hasbro's boardgame Risk. It doesn't look very good, and it's probably a spoof. Then there is riskmovie.com, which appears to be an already filmed and shown version of the game, but it doesn't come across very serious.
But now we'll see the pro's in blockbuster film making taking on one of the best boardgames ever made. They say that the gambles and excitement you experience while playing the game translate well to an thrilling movie experience. But I say: prove it first, then I'll believe.
Other games which have been mentioned to have actors and studios interested in making film version include Monopoly, Battleship and Candyland.