Basic Information
Frequently known as "That RPG" , Dungeons & Dragons (the ampersand is, apparently, important and was once dragon shaped in its own right) is - certainly in the English speaking world - the predominate TTRPG both by profile and market share. The progeny of Gary Gygax and Dave Arneson, the game evolved from various forms of skirmish wargaming and was first published in 1974. It has continued to change … for good or ill … ever since.
Due to its role as the four hundred pound gorilla of the RPG industry, it has driven a great number of the tropes and expectations for RPGs in the popular imagination - it is, for example, the Ur-example of the class and level system.