Logicola

To oversimplify things a bit, D&D draws heavily from at least two very different strands of fantasy literature: the grim and sometimes savage world of “swords and sorcery” (think Conan); and epic, heavily plotted, highly moral high fantasy (think Tolkien). The influence of Conan-esque swords and sorcery can be seen in many core elements of D&D: dungeons to explore; treasure and money as a prime motivation for adventuring; the heavy representation of rogue-ish classes like the Thief, Bard, Assassin, and Illusionist; a very deadly world; and more. The influence of Tolkien-esque fantasy can be seen in many other elements: the character races available for play; lots of strange and interesting magic weapons and items; parties of adventurers who all work together; and countless “classic” monsters.

via Sandbox gaming vs. adventure paths: in defense of highly narrative adventures « The Lost Level.