Pendragon, also known as King Arthur Pendragon, is a role-playing game that is part of Chaosium's Basic Role-Playing game system. In the game players take the role of knights performing chivalric deeds in the tradition of the Arthurian legends. The game was originally published by Chaosium and later published by Green Knight Publishing and White Wolf, Inc.'s Arthaus label: it is currently published by Nocturnal Media.
Because the 1st thru 5th editions are so close rules-wise, they are treated as a single RPG. (Note that there is no 2nd edition.)