Advanced Dungeon and Dragons was an updated version Dungeon and Dragons which reorganized and restructured the rules into 3 seperate hardback rulebooks or some might say tomes that added new character classes and magazine articles and to borrow a pop culture term, made them cannon. This set of books known as the core rules came out in 1978. 11 years later in 1989 The 2nd edition was release and added new rules and information in 2000 came the 3rd edition which was published by a new company Wizards of the West Coast. TSR (Tactical Studies Rules) had orginally published ADnD until the company was sold in 1997. The fourth Edition would have to wait until 2008 because in 2003 came ADnD 3.5 which addressed questions of game balanced,corrected rule errors and added new information. ADnD 5th edition came out in 2012 offering new classes and new rules to streamline certain parts of the game. For the 50th anniversary a revised version of the 5th edition is being released.