Player: "OK, so what number do I have to roll?"
DM: "Don't ask me how high you have to roll; just roll the dice and I'll tell you whether you succeed or fail."
Player: "COWARD!"
DM: "What?!"
Player: "No more hiding the dice. Do more hiding behind your oppressive tables and fascist matrices. No more hiding behind your authoritarian DM screen. I'm calling you out Dungeon Master. Come out of your fortress and face me!"
DM: "Foolish mortal! You dare to challenge me? So be it! Prepare to die FWA HA HA HA HAA!"

The Dungeon Master is an evil sorcerer who hides in a tall onyx tower where he rolls the dice of fate in secrecy, and manipulates the results to subjugate the masses. His tower is surrounded by high walls to conceal his face and his knowledge. This callous panopticon peers out from his dark chambers and forces his slaves to collect fresh MacGuffins daily and transport them to him via railroad.

You are an Adventurer. You don't fight for gold. You don't fight for experience. You fight for freedom, consistent rules, and system transparency. You must pry these liberties free from the cold clutch of the Dungeon Master. You must tear down his walls and expose his dice and his books to the world.

The Dwarves were once great great Magic-Users before the Dungeon Master banned them from spellcasting, citing concerns over 'game balance' and 'setting' as the cause bellum. Now the Dwarves are forced to fight only with brute force, but they practice magic in secret in hopes of one day becoming great wizards and overthrowing the Dungeon Master.

The Orcs are a once proud warrior race enslaved by the vile and decadent Hobbits. Someday they shall throw off their shackles, rise up against their Hobbit overlords, and bring about the liberation of technology.

Humans are a species of tough and adaptable nomadic hunter-gatherers with fantastic throwing-arms and extraordinary powers of long-distance travel. For some reason though, the Dungeon Master's propaganda depicts them as 'ordinary' and 'borderline' with no special advantages or disadvantages. The Humans want to dispell these lies and show the world that they can be just as special and unique as all the other races.

Awesome. You're liberating Dungeons and Dragons ... from itself.
Ha, couldn't resist the super-easy, super-cheesy setup of that line.
Is this a game idea, or just what you called it - a random musing?

It could very well be a game idea.
I've been toying with ideas for a fantasy heartbreaker based on D&D for a while. I like both 4E and the retro-clones, and I've been wanting to combine the elements of the two, but I don't just want it to be a mere rules-variant. So why not make it a parody?

I had these thoughts last night (inspired more by 0e, btw):

Elves are behind it all - ordinary by nature, they've used stolen magic to become great at everything!
Elves struggle to: be plain or unremarkable. Any time it would be useful not to draw attention to oneself, the elf's player must roll. Not if he's trying to sneak in a forest, of course. That's highly elfin. They can be ostentatious and wondrous without effort, though.

Dwarves struggle to: handle anything magical. Their beards show them to be clearly good at wizardry, but the elves took care of that! They took their height, too, to make themselves more imposing... Dwarves can make magic fail in their presence without effort.

Orcs struggle to: resist their evil impulses. Orcs aren't evil by nature, only wild, fractious, and whimsical; chaotic. They used to be more moral and more high-minded, but the elves were too petty and cruel to win anyone's respect. So they stole the orcs' capacity for good! Whenever it would be useful not to be cruel or a self-serving bastard, the orc's player must roll. Orcs can be cruel and vicious without effort.

Humans struggle to: be distinctive and noticeable. Their great capacity for heroics, for amazing feats, has been stolen by the elves; now they're all tediously average and boring! Whenever a human wants to do something exciting or distinctive, the player must roll. Humans can be plain and unassuming without effort.

Halflings struggle to: be hobbits. They were once a serious, hard-working people with their feet on the ground. The elves, needing a firmer backbone if they were to rule the world, stole the hobbits' sense of scruples and responsibility, leaving them as ... halflings. A halfling can be coy, plucky, courageous, or thieving without effort, but the halfling's player must roll for him to do anything well-thought-out, cautious, or conservative.

Yeah, and I had this idea that you start out with a certain number of True Nature and Elf-Curse points, which always add up to ten or something - the elf-curse is the trait that's been forced on you, and the true nature is your race's real identity. If my orc really needs to resist his urge to abuse and dominate the villagers, he'll need to make a series of True Nature checks during his work with the village council. If he does well, he could transfer a little of his Elf-Curse points into his True Nature points.
When the Elf-Curse has been totally evaporated, the demihuman is utterly prepared to join the cause of defeating the Dungeon Master, who's probably a boring, little old elf behind that black-iron helmet of his... Demihumans can of course join the cause before this point, but they have a liability in the Elf-Curse.

Good ideas!

I was actually thinking of a broader system of "Doctrines" that must me broken down somehow.
Doctrines impose limitations on players and their characters. Some doctrines apply only to certain races and classes.
Example...

Dwarf
Doctrine: Magic-Ban
Dwarves cannot use spells or become Wizards.
Doctrine: Faith-Ban
Dwarves cannot use prayers or become Clerics.
Doctrine: Nature-Ban
Dwarves cannot use instincts or become Druids.
Doctrine: Short
Dwarves cannot grow taller than 4 feet.

Some doctrines are broader in scope, such as those that allow the DM to maintain control of the world.
Player characters can attack doctrines however and destroy them to gain more options.

I like it. As for the doctrines thing, it reminds me of a discussion over at storygames.com a while back, where the idea was that each race or class or whatever had certain limitations, like "Drow are evil" "Drow females rule their society" or whatever, and then your character would be able to break several of these restrictions as part of their character concept.

This is a bit different though, with the whole race breaking "traditional D&D" ideas, which are in setting lies perpetrated by the dungeon master.

Who believes the lies though? Certainly not all the races hate the dungeon master, there're bound to be NPCs, those most malicious and dangerous of the DM's servants.

I should think that GMCs would be more dangerous than the fairly neutral, standoffish NPCs.

I was thinking maybe the filthy Hobbitses could be secondary antagonists.
I've been inspired by this article by Michael Moorcock:
http://www.revolutionsf.com/article.php?id=953

In this default setting I'm imagining, the Halflings are a race of priveleged bourgeois fiercely subservient to the Dungeon Master. The only thing they value over the status quo is their decadent lifestyles, so they enforce the doctrines in order to preserve their 'peaceful' way of life.