It's a special holiday episode of The Big Bang Theory. Tonight's episode of The Big Bang Theory is called "The Santa Simulation," and it features a game that many of our readers likely fondly remember. According to the CBS description, "Sheldon revisits some Christmas memories during a game of Dungeons and Dragons, while Penny, Bernadette and Amy try to find a girl for Koothrappali when he joins the girls for ladies' night." "The Santa Simulation" episode of The Big Bang Theory airs on Thursday, December 13 at 8 PM ET on CBS. Check out our sneak preview of the episode which features a special appearance by Santa Claus. Photo Credit: Monty Brinton/CBS.