Real or fake? In this case, more than likely fake. This illuminated chess scene, LJS 33, was painted on a parchment leaf scraped of its original text and musical notation. The illumination was probably painted in France circa 1900 by a Spanish forger.
But the forger picked the subject well as chess was a popular game in the medieval period. There are several surviving chess sets, including the one depicted here which is housed in the British Museum. In addition, manuscripts have been know to depict friends and couples playing chess and other games, such as on fol. 29r of W.102 from the Walters Museum depicting St. Stephan in the middle of a chess match.
Manuscript description and digitized images can be found on OPenn; http://openn.library.upenn.edu/Data/LJSchoenbergManuscripts/html/ljs33.html
Information on W.102 can be found on the Digital Walters; http://thedigitalwalters.org/Data/WaltersManuscripts/html/W102/description.html