The gameplay consists of a mixture of action, adventure, driving, and occasional role-playing, stealth and racing elements and has gained controversy for its adult nature and violent themes. The series focuses around many different protagonists who attempt to rise through the criminal underworld, although their motives for doing so vary in each game. The antagonist in each game is commonly a character who has betrayed them or their organization or someone who has the most impact impeding their progress. The series began in 1997 and currently has nine stand-alone games with a tenth one on the way, and two expansion packs for the original. Film veterans such as Danny Dyer, Michael Madsen, Burt Reynolds, Dennis Hopper, Gary Busey, Samuel L. Jackson, Chris Penn, James Woods, Joe Pantoliano, Frank Vincent, Robert Loggia, Kyle MacLachlan, Peter Fonda and Ray Liotta have all voiced major characters in many installments in the series. The name of the series and its games are derived from grand theft auto, a term referring to motor vehicle theft. As of 26 March 2008, the franchise has sold over 70 million copies worldwide; according to Take-Two Interactive.