From Wikipedia:
Vin Diesel (born Mark Sinclair Vincent; July 18, 1967) is an American actor, writer, director and producer. He became known in the early 2000s, appearing in several successful Hollywood films, including The Fast and the Furious and xXx. He founded the production companies One Race Films, Tigon Studios and Racetrack Records.
Diesel has played Dungeons & Dragons for over twenty years and wrote the foreword for the commemorative book 30 Years of Adventure: A Celebration of Dungeons & Dragons. In the 30th Anniversary of Dungeons & Dragons issue of Dragon Magazine, they examine the fact that Diesel played Dungeons & Dragons, and reveal that he had a fake tattoo of his character's name, "Melkor," on his stomach while filming xXx.
Diesel has an interest in the online MMORPG World of Warcraft as seen in interviews with Jonathan Ross and Curt Schilling, and also as evidenced by the installation of a computer game system on one of his cars.
User addendum:
Diesel is the subject of the RPG, XXXXtreme STREET luge. His voice or likeness has appeared in the videogames The Chronicles of Riddick: Escape From Butcher Bay, The Chronicles of Riddick: Assault on Dark Athena, and Wheelman.