Dungeons and Dragons
The original fantasy role-playing game¸ a swords-and-sorcery genre game vaguely based on Tolkien¸ Howard¸ and Lieber. The first edition in 1973 was an add-on to Guidon Games' Chainmail miniatures rules. It was a boxed set with three booklets (""Men & Magic""¸ ""Monsters & Treasure""¸ and ""The Underworld and Wilderness Adventures""). This used the term ""hobbits"" which was changed to ""halflings"" in the reprint after a clash with the Tolkien estate.
Later¸ after AD&D was released¸ the ""Basic Set"" was re-introduced as an easier first introduction to AD&D¸ covering only levels 1-3. Races were ""simplified"" to each be their own class (i.e. so elves are ""elf"" class instead of being forced to be mixed Fighting Man / Magic-user). In 1980 this was then expanded into a separate line of game sets: Basic / Expert / Companion / Master / Immortal. The first two sets went through several editions¸ and then the first 4 sets were later collected and edited into the ""Rules Cyclopedia"". This line was dropped in the mid-90's.
The ""3rd edition"" is really a new edition of AD&D with a wholly redesigned system¸ known as the ""D20 System"". The ""Adventure Game"" is a standalone boardgame with 8 pregenerated characters along with 3 premade adventures and random dungeon generators¸ but with no character generation rules. - A description from https://darkshire.net/jhkim/rpg/encyclopedia/ with kind permission of John H. Kim"