Back in the day, I had the good fortune to be friends with a bunch of nerds. These nerds, taken collectively, connected me to most of the various nerd tribes, but there was a specific preponderance of Tolkien among their specific schools of nerditude. 2000-2003 were good years to be a Tolkien nerd, thanks to the efforts of various Australians, and it was comparatively easy to pick up my slack in that area. (Full disclosure: I still have not read Lord of the Rings. I read The Hobbit and Fellowship of the Ring, but got caught up in thesis prep about 60 pages into The Two Towers. So my thoughts on Tolkien aren't exactly authoritative.)
My nerd lineage starts with videogames and spreads out from there. I've never seen the pre-Special Edition Star Wars, and therefore never saw any of them until I was 15 years old. Nonetheless, at 15, I developed a near-encyclopedic knowledge of the universe through games and a wonkish interest in Joseph Campbell. Similarly, I've never played Dungeons & Dragons, but picked up the basics of the ruleset through adaptations, and the elements that spread throughout the RPG genre. So, as I watched the Rings movies, I'd see a lot of things I recognized from various RPGs, many of them Japanese, and my Tolkien nerd friends would smugly assert that, of course, everything in the fantasy genre has a straight line back to Tolkien.
I thought this was a little odd at the time, in that even I knew that Gary Gygax and company had at least one other major influence, Robert E. Howard, in establishing the D&D universe. From what I've read since then, it turns out that Gygax wasn't a big fan of Tolkien--he liked the American pulps, mostly--and the references to LOTR in D&D mostly amount to marketing ploys. More to the point, however, what makes D&D important has very little to do with evocative world-making. I don't know if Gygax's rule system was the first or even the most effective of its time, but it seems to me that the relevant thing about D&D as it relates to videogames and simulation in general is that it devised a system for measuring human behavior through the narrativized interaction of random and non-random statistics.
Case in point: A D&D character is fundamentally comprised of 6 base statistics: Strength ("the muscle and physical power of your character"), Dexterity ("agility, reflexes and balance"), Constitution ("the health and stamina of your character"), Intelligence ("how well your character learns and reasons"), Wisdom ("willpower, common sense, perception and intuition"), and Charisma ("force of personality, persuasiveness, ability to lead, and physical attractiveness").
Ok, that's all well and good, but what do they do? Narrative niceties aside, the issue is how it ties into actual gameplay. (I'll be referring to the NWN ruleset here, so, y'know, take heed.) Strength covers carrying capacity, melee weapon damage, and the "discipline" skill, which resists various combat skills. Dexterity covers bow damage and dodging, as well as hiding, sneaking, lock picking, parrying, pickpocketing, and setting traps. Constitution covers HP (i.e. how much damage one could soak up and survive), as well as concentration and the barbarian's "rage" ability. Wisdom allows characters to ask more insightful questions to NPCs to get better information, covers divine magic for clerics, druids, paladins and rangers, enhances monks' dodging abilities, and contributes to healing, listening, and looking. Intelligence covers the acquisition of new skills (general learning speed), as well as arcane magic for wizards and the disable trap, lore, search, and spellcraft (counter-magic) skills. Charisma covers arcane magic for bards and sorcerers and contributes to animal empathy, singing, persuasion, taunting, and using magic devices.
So we're now in a bit deeper; certainly better than the bare-bones "physical/mental/other" trinity from which most RPG rulesets are, ahem, divined. And we've covered a good many things a hypothetical person could do, with a semi-coherent system for what skills govern which actions.
What interests me most at this point is the treatment of the mind: at first glance, two of the main stats, intelligence and wisdom, seem to cover this category. The manual notes that high intelligence and low wisdom makes for something of an idiot savant, while high wisdom and low intelligence makes for a kind of non-specific street smarts. After all, "wisdom" comprises a fairly wide array of concepts--willpower, common sense, perception and intuition--it's a pretty heavy stat, from a narrative level. (Notably, Arcanum goes to the trouble of breaking it into "willpower" and "perception.") So we have two stats standing in for "mind." Except...charisma? That's more "interpersonal" than smart, so maybe that's a third category. And once we're into threes, hoo boy. One could alternatively divy up the stats into physical, mental and spatial/temporal, or internal, external and liminal: strength and constitution for the objective, visible world, intelligence and charisma for mind and speech (speech being, in this projection, a manifestation of the inner self), dexterity and wisdom for the relation of the world to the self. That these pairings seem to oppose each other--constitution makes enemies' strength less effective, wisdom counteracts dexterity skills--adds some legs to this model.
One more thing about these skills, which have (of course) evolved considerably over many iterations of D&D: saving throws. Certain attacks, curses, etc. can be turned aside by fortitude (constitution), will (wisdom), or reflex (dexterity) saves. In the 4th edition ruleset, all six stats contribute to saving throws, essentially pairing off the starting six: strength and constitution, dexterity and intelligence, wisdom and charisma. And this pairing also makes a kind of sense, which raises a new question: do any of these stats really work in isolation? I mean, in the universe we actually inhabit?
In practice, it's difficult to build muscle without also improving endurance and general cardiovascular health. Dexterity is a matter for people with more medical knowledge than I, but there's certainly a fairly significant physical component. Similarly, how well can one actually think with an unhealthy body? If the brain itself--a physical organ that runs on oxygen and regulates an unfathomably complex machine via electrochemical signals--doesn't problematize mind/body dualism, perhaps the ubiquity of anti-depressants in modern American society will. And shouldn't the "willpower" part of wisdom affect all of these?
Working from this concept, one could easily split up the starting six into primary and secondary groups, making the secondary stats by combining the primary. Wisdom and dexterity are pretty convincing as the building blocks of charisma, at least where I'm stanging--dexterity is already associated, metaphorically, with wit and mental processes, and a general comfort with and awareness of one's company and surroundings is always the part of interpersonal relations at which I suck.
There are a theoretically infinite number of these kinds of models that can be produced, of course, even with a relatively small number of variables, just by rearranging the relationships between them. And each of these models would no doubt be consistent with some aspects of observed or imagined reality and not others. RPGs aren't my favorite genre to play, but they're definitely my favorite genre to think about, for the same reason I find my liberal-arts-major knowledge of science so useful in my everyday walkin' around time: it gives you a new way to look at your regular, boring-ass life.