In her work on the origins of roleplaying games (which includes a dissertation on them), Nephew pays attention to how RPGs borrow characters, scenarios, creatures and settings from other media, in both private and published games (appropriating the character of Black Leaf from Jack Chick's infamous comic, Dark Dungeons, is a much-abused cliché). Nephew finds a precedent for this culture of creative exchange in the pulp magazines of the '20s and '30s. In those publications, writers and fans communicated so frequently and with such intensity that much of the writing of that time can be understood as a sort of mass collaboration. Writers also borrowed extensively from each other, yoinking characters or creatures or even the authors themselves. H.P. Lovecraft and Robert Bloch each famously knocked off a character based on the other in complementary tales.
The extensive collaborations of pulp fiction resulted in what Nephew calls a "synthetic mythology," a shared, imaginary world very much like the ones developed by a group of roleplayers. When RPGs first appeared, synthesizing a background for games quickly became a legal consideration.
The first printing of Dungeons & Dragons borrowed Tolkien's hobbits and ents. Among the early D&D books that collectors prize most are those featuring copyrighted material used without permission. In its early days, Tactical Studies Rules, the first publisher of D&D, received many a cease-and-desist order; in its later days, before Wizards of the Coast bought it out, it issued many of its own. Right from the start, entrepreneurial geeks looked at the amateur production values of the 1974 D&D booklets and decided that they, too, could put together a roleplaying game. To this day, some game designers actually criticize RPGs that intimidate amateur authors with their too-slick, too-professional products. RPG culture has always warred with itself about the business of making games, just as players debate how to run their game of D&D.
Gary, Dave and Aeschylus
Let's go back to those Greeks for a moment. Back in their day, a stage play consisted of a single actor and a chorus. There was no drama as we know it, until the great playwright Aeschylus introduced a second actor who exchanged dialogue with the first. This innovation is what Jorge Luis Borges calls a moment of "modest history." This wasn't a war or a revolution or technological change or the meeting of civilizations. This was a subtler transformation. Aeschylus essentially invented acting, forever changing entertainment.
Dungeons & Dragons may mark a similar moment. When wargames shifted from history to fiction, from armies to individuals, when roleplaying became a means of collective creativity rather than a technique of therapy, we may have experienced a change that, just like the invention of drama, will affect humanity for thousands of years to come. The two crazy elements that made it impossible for anyone to invent D&D before Gygax and Arneson are precisely what will endure in media yet unknown to us. Just as acted dialogue is essential to movies and television, so a taste for chaos and a collaborative spirit will define the entertainment of the future.