Hmmm, actually... Isn't most AD&D stuff related to nearly identical to Tolkien's works? Stuff like mages, elves, halflings/hobbits, area names, etcetera? Even if it isn't related to Tolkien's works and just to AD&D, then you've got to remember AD&D is also owned by a company called Wizards of the Coast. For example, all the AD&D manuals are copyrighted to WotC.

Really kinda disturbing; even our fantasy has been copyrighted these days...