Lols' I just read on some norwegian page that,

VIN DIESEL PLAYS DDO!


Source:
http://mann.no.msn.com/kultur/galler...ntid=155331590

Translated text

Vin Diesel has a long film resume full of roles that will lead, muscular, loud "bad asses". Private he has - for the past 20 years - has been a persistent Dungeons & Dragons players, under the name Melkor. Diesel wrote to and including the preface to the book "30 Years of Adventure: A Celebration of Dungeons & Dragons" from 2004."
His ign is Melkor (as said in the quoted text)