Gary Gygax and Dave Arneson designed Dungeons & Dragons.
Dungeons & Dragons ( abbreviated as D&D or DnD ) is a fantasy tabletop role-playing game ( RPG ) originally designed by Gary Gygax and Dave Arneson , and first published in 1974 by Tactical Studies Rules , Inc. ( TSR ) . Ernest Gary Gygax ( [ ˈɡaɪɡæks ] ) ( July 27 , 1938 -- March 4 , 2008 ) was an American game designer and author best known for co-creating with Dave Arneson the pioneering role-playing game Dungeons & Dragons ( D&D ) .