There are many works of fiction that D&D draws upon for inspiration, as co-creator Gary Gygax made clear with his Appendix N in the Advanced Dungeons & Dragons Dungeon Master's Guide. Jon Peterson identified a theme that some of the Appendix N fiction has in common, known as a "visitation theme." It serves as a useful template for how D&D is portrayed -- now and in the future.
The First Level: Playing Yourself
The visitation theme in fiction is summed up by Jon Peterson in Playing at the World:
The theme is common with child protagonists, who are more open to fantastic worlds through their imagination, traversing gateways to other realms; Alice in Wonderland, The Wonderful Wizard of Oz, and The Lion, the Witch, and the Wardrobe being three popular examples. In the hands of an adult -- who brings a developed skill set with them -- things can take quite a different turn. One of the best examples of this idea is Mark Twain's A Connecticut Yankee at King Arthur's Court:
A more recent example of this idea in film is Ash Williams in Army of Darkness: a modern time traveler who is thrust into a fantasy world, and uses his modern know-how to his advantage.
Role-playing's unique application of real life concepts (codified monsters and magic, rules for spells, characters neatly divided into races and classes) finds a useful parallel in this fiction theme, where D&D transports its players into a fantasy world for a few hours. It is a halfway between fully immersive role-playing and modern sensibilities -- players are not expected to literally think and act like their characters. In fact, co-creator of D&D's Dave Arneson's first Blackmoor campaign featured the characters playing themselves, as per David Hartlage:
Escape rooms adopt this form of "light" role-play in which the player is expected to be herself, but still bring her know-how to a fictional challenge in order to escape.
There are plenty of reasons why this idea might not appeal to players, of course, not the least of which being that a realistic depiction of a player may not be physically capable of handling the challenges of a fictional universe. For game purposes, it can be more fun to adopt a persona that merges the player's mind with a character's body.
The Second Level: Playing a Hero
If Twain's take on proto-role-playing is a bit jarring to modern audiences, Edgar Rice Burrough's Barsoom series (featuring John Carter) and The Compleat Enchanter stories (featuring Harold Shea) by Fletcher Pratt and L. Sprague de Camp provides a template that's more familiar to gamers:
In both series, the protagonists are not merely transported to new realms but transformed. Harold Shea discovers he speaks Old Norse, cannot read English, and the world's core physics prevent him from using his modern sensibilities like lighting a match. Similarly, John Carter has great strength and superhuman agility thanks to Mars' lesser gravity and lower atmospheric pressure. The heroes still have their own minds, but they are in different bodies.
Perhaps the most influential of these types of visitation themes is Poul Anderson's Three Hearts and Three Lions. Holger Carlson, an American-trained Danish engineer, finds himself in a fantasy realm where his newfound armor fits him perfectly, he knows how to use his weapons and ride a horse, and he can speak the local language. Three Hearts and Three Lions gave us D&D's paladin, complete with "laying on hands" and regenerating trolls. Even R.E. Howard's Conan -- another highly influential character on D&D -- was not immune to visitation fiction, in which John O'Brien relives his past life as Conan in "People of the Dark."
This version of visitation fiction is slightly more immersive than the first, and is used to good effect in the Dungeons & Dragons cartoon. Our six young heroes are thrust into competent bodies who have equipment that fits them perfectly and (mostly) know how to use them. This is a parallel for D&D itself, which asks players to invest partially in their fantasy character tropes without fully immersing themselves in it: they didn't have to become a fantasy character, they just play one.
Villains & Vigilantes is one of the first superhero role-playing games to formalize this level of immersion, in which a player was the real-life secret identity to the superhero she played in the game. This mimics cosplay as well, in which players adopt a persona of a hero or villain in appearance only. For full-immersion that blurs the line between player and character, we must dive into the third level.
The Third Level: Becoming the Character
Thinking and acting like your character is not unique to Dungeons & Dragons, but it requires a level of commitment above and beyond the first two levels of immersion.
This form of role-play has become increasingly popular with role-play only servers in massive multi-player online role-playing games (MMORPGs), where most game play is firmly stuck in level two -- players usually talk about real life through their characters without any clear distinction between them. Part of this is certainly due to the medium, where a player is using a computer to connect with his character and thus can only engage with the game at the second level of engagement.
Conversely, Live Action Role-Playing (LARPs) works actively to not use the first level of engagement (like cosplay, an easy mode to slip into since the player is physically part of the game). Many LARPs emphasize level three only. Full immersion at this level can create "bleed" in which the emotions of characters affect players.
Pitching D&D
There's a reason why visitation fiction is popular, and it has its parallels in D&D itself. As Peterson states:
This technique, which eased readers into fantasy, also eases gamers into role-playing. Visitation fiction lets you dive right in: While there are certainly peculiarities of any fantasy visit, modern players don't have to worry too much if they know how to swing a sword, or ride a horse, or speak the local language. If the upcoming D&D film is to distinguish itself from other fantasy movies, the visitation theme might make the difference.
The First Level: Playing Yourself
The visitation theme in fiction is summed up by Jon Peterson in Playing at the World:
There is however a trajectory in fantasy literature running through Burroughs, de Camp and Anderson, which also surfaces in the works of Moorcock and Howard, that demonstrates precisely this sort of connection between fantasy and the denizens of the "real" modern world...The formula is a simple one: plausible contemporary persons undertake a journey to an undiscovered, fantastic realm, where after some adventures they return to their place of origin.
The theme is common with child protagonists, who are more open to fantastic worlds through their imagination, traversing gateways to other realms; Alice in Wonderland, The Wonderful Wizard of Oz, and The Lion, the Witch, and the Wardrobe being three popular examples. In the hands of an adult -- who brings a developed skill set with them -- things can take quite a different turn. One of the best examples of this idea is Mark Twain's A Connecticut Yankee at King Arthur's Court:
Morgan applies nineteenth-century engineering know-how to the raw materials of the period, and his accomplishments quickly outstrip those of deranged mystics like Merlin, to say nothing of the martial prowess of the knights themselves. Eventually, in the final confrontation between American ingenuity and English hereditary privilege, Morgan handily butchers the flower of British nobility with dynamite, Gatling guns and electric fences.
A more recent example of this idea in film is Ash Williams in Army of Darkness: a modern time traveler who is thrust into a fantasy world, and uses his modern know-how to his advantage.
Role-playing's unique application of real life concepts (codified monsters and magic, rules for spells, characters neatly divided into races and classes) finds a useful parallel in this fiction theme, where D&D transports its players into a fantasy world for a few hours. It is a halfway between fully immersive role-playing and modern sensibilities -- players are not expected to literally think and act like their characters. In fact, co-creator of D&D's Dave Arneson's first Blackmoor campaign featured the characters playing themselves, as per David Hartlage:
Dave Arneson’s Blackmoor game—the campaign that spawned D&D—began with a gaming group playing fictional versions of themselves in a fantasy world. The characters became champions in series of miniature battles featuring armies clashing above ground. Without any further inspiration, the Blackmoor game might have evolved into a role-playing game such as Chivalry & Sorcery, a game I found short on fun. But somehow, Dave invented a new activity that transformed the campaign and ultimately made a lasting addition to popular culture.
Escape rooms adopt this form of "light" role-play in which the player is expected to be herself, but still bring her know-how to a fictional challenge in order to escape.
There are plenty of reasons why this idea might not appeal to players, of course, not the least of which being that a realistic depiction of a player may not be physically capable of handling the challenges of a fictional universe. For game purposes, it can be more fun to adopt a persona that merges the player's mind with a character's body.
The Second Level: Playing a Hero
If Twain's take on proto-role-playing is a bit jarring to modern audiences, Edgar Rice Burrough's Barsoom series (featuring John Carter) and The Compleat Enchanter stories (featuring Harold Shea) by Fletcher Pratt and L. Sprague de Camp provides a template that's more familiar to gamers:
Intriguingly, the stories of John Carter and Harold Shea are prominently mentioned by Gygax in the foreword to Dungeons & Dragons as inspirations for the game--together they constitute two out of the four fictions that he expects Dungeons & Dragons to emulate...There is a certain intrinsic kindship between these stories of twentieth-century persons visiting fantasy worlds and the play of Dungeons & Dragons, where we as players set aside our mundane selves temporarily to assume a fantastic role.
In both series, the protagonists are not merely transported to new realms but transformed. Harold Shea discovers he speaks Old Norse, cannot read English, and the world's core physics prevent him from using his modern sensibilities like lighting a match. Similarly, John Carter has great strength and superhuman agility thanks to Mars' lesser gravity and lower atmospheric pressure. The heroes still have their own minds, but they are in different bodies.
Perhaps the most influential of these types of visitation themes is Poul Anderson's Three Hearts and Three Lions. Holger Carlson, an American-trained Danish engineer, finds himself in a fantasy realm where his newfound armor fits him perfectly, he knows how to use his weapons and ride a horse, and he can speak the local language. Three Hearts and Three Lions gave us D&D's paladin, complete with "laying on hands" and regenerating trolls. Even R.E. Howard's Conan -- another highly influential character on D&D -- was not immune to visitation fiction, in which John O'Brien relives his past life as Conan in "People of the Dark."
This version of visitation fiction is slightly more immersive than the first, and is used to good effect in the Dungeons & Dragons cartoon. Our six young heroes are thrust into competent bodies who have equipment that fits them perfectly and (mostly) know how to use them. This is a parallel for D&D itself, which asks players to invest partially in their fantasy character tropes without fully immersing themselves in it: they didn't have to become a fantasy character, they just play one.
Villains & Vigilantes is one of the first superhero role-playing games to formalize this level of immersion, in which a player was the real-life secret identity to the superhero she played in the game. This mimics cosplay as well, in which players adopt a persona of a hero or villain in appearance only. For full-immersion that blurs the line between player and character, we must dive into the third level.
The Third Level: Becoming the Character
Thinking and acting like your character is not unique to Dungeons & Dragons, but it requires a level of commitment above and beyond the first two levels of immersion.
This form of role-play has become increasingly popular with role-play only servers in massive multi-player online role-playing games (MMORPGs), where most game play is firmly stuck in level two -- players usually talk about real life through their characters without any clear distinction between them. Part of this is certainly due to the medium, where a player is using a computer to connect with his character and thus can only engage with the game at the second level of engagement.
Conversely, Live Action Role-Playing (LARPs) works actively to not use the first level of engagement (like cosplay, an easy mode to slip into since the player is physically part of the game). Many LARPs emphasize level three only. Full immersion at this level can create "bleed" in which the emotions of characters affect players.
Pitching D&D
There's a reason why visitation fiction is popular, and it has its parallels in D&D itself. As Peterson states:
...we need only appreciate that the prevalence of the visitation theme is one of the dominant factors that ensured role-playing games began in a fantasy setting, rather than some other genre. These stories taught reads how to role-play when immersed in a fantasy narrative: how to follow the example of a Connecticut Yankee, of Harold Shea, or Holger Carlson. The immense popularity of Tolkien seeded a global marketplace for fantasy that was cleverly exploited by both Chainmail and Dungeons & Dragons, both of which transcended the popular distaste for warfare by setting their action at a great remove from modern weaponry and casting their battles in a world of moral absolutes, among evil beasts that can be slain without qualms.
This technique, which eased readers into fantasy, also eases gamers into role-playing. Visitation fiction lets you dive right in: While there are certainly peculiarities of any fantasy visit, modern players don't have to worry too much if they know how to swing a sword, or ride a horse, or speak the local language. If the upcoming D&D film is to distinguish itself from other fantasy movies, the visitation theme might make the difference.
WNwP&D use to be available online but now I can only find them via archive.org. 
