Well, that's because you made assertions about "the fight with Torog", and about it being the same as a heroic-tier dungeon crawl, and the only poster in this thread who has posted an example of a fight with Torog is me.
Using your example as an example is hardly proof my primary interest is proving something about your game.
Who is the we? Not someone who was introduced to RPGing via HeroQuest, or Marvel Heroic RP, or even Runequest (roll under Swim score compared to roll under Climb score).
*facepalm* That would be mechanical differentiation. Swim is not the same as Climb because walls are not the same as pools (unless walls and pools really are the same, which I suppose is possible).
Look at it this way. A wall is defined in game as being (among other things) that sort of obstacle which you can apply a climb skill check on, while a pool is defined in game as being (among other things) that sort of obstacle which you can apply a swim check on. This is the sort of thing that is so basic you probably never think of it, but its their lurking under the surface. In this way, walls and pools are defined as being inherently different. If on the other hand, these were the only relevant in game features of the two (and generally it wouldn't be in most PnP games, for instance one tend by definition to block line of sight and or line of effect), and all the system had was an atheletics check, it might end up being that the fictional positioning of wall versus a pool didn't matter.
Can you tell I write software for a living?
If you want to teach a computer to run an RPG, you have to make all this explicit. In a computer, the difference between flavor and mechanics is really clear. It's equally clear in a PnP RPG (at least to me), but PnP RPGs tend to have far more rules than people realize. Yes, the SRD does explicity define what a wall means in the game. Most people never think about that, they just assume that walls obey 'realistic' rules.
D&D doesn't mechanically differentiate between fighting with a dagger or with a spear.
Sure it does. Different damage dice, different reach, different weight, different size, different critical types, and different options between the two. There are plenty of situations where it matters mechanically which you are wielding. You can't slice your way out of a purple worm with a spear, or set to recieve a charge with a dagger. In 1e AD&D there would also have been different speed factors and different weapon vs. armor modifiers - it would have matter greatly which you were using against full plate.
Contrast Burning Wheel, which does.)
I'm not that up on the Burning Wheel rules, but IIRC correctly Burning Wheel operates at different granularities and attempts to achieve mechanical differentiation between weapons in different ways. That's different, but not the same as no mechanical differences. You might have been on target if you'd said something like OD&D did not mechanically differentiate between a short sword and a handax (or maybe even between weapons at all, that was before my time).
It barely differentiates between fighting with a dagger and fighting with a bow.
I guess that's a matter of opinion. I certainly see some differences in mechanical resolution. But I think you are meaning by 'mechanical resolution' only overall system. That is, D20 usually involves throwing a D20 against a target number, and on success performing some resolution, as opposed to throwing a dice pool and totalling the number of successes. That seems an overly narrow definition of mechanics.
Mechanical differentiation is not all that counts. The mechanics for resolving negotiations with a shopkeeper, and negotiations with a king, are no different in any pubished RPG of which I'm aware (including D&D, any edition). Yet I've never heard it suggested that the two are really the same experience.
Well, while it may be true that mechanical differentiation is not all that counts, I would suggest that negotiations between a shopkeeper and a king are similar enough that they belong in the same category of thing.
As for mechanical differences in negotiating with a King and a shopkeeper, the overall rules may be the same - roll a d20, compare the modified result to a modified target - they are at least potentially different in D&D RAW and are certainly different among many common D&D social rules variants. For example, if you perform an Intimidate check on the King and the shopkeeper, the King's status is likely in most D&D played RAW to impact the odds of success. For example, the King may have higher HD, higher Will saves, etc. Likewise, the King and the Shopkeeper might be mechanically represented by different amounts of Sense Motive skill, differentiating the ease of Bluffing one or the other - perhaps in this case our Shopkeeper has higher Sense Motive than the gullible King. In my case, if you were trying to persuade the King of something, your station in life relative to the King would impact the difficulty of doing so. All other things being equal if you are a slave or shopkeeper, for example, the King is much less likely to hear your suggestions favorably than he would if you were a knight or duke, and more likely to consider your statement impertinent.
But I see very little difference ultimately in being a slave negotiating with a shopkeeper and a knight negotiating with a king.
Fictional positioning can matter to framing, to feasible action declaration, to choice of ability to deploy and/or resource to expend, to narration of consequences, to setting of DCs, etc. These are all significant things in RPG mechanics. You don't need to also change the basic resolution system to make fictional positioning matter.
I think you are trying to count a lot of things that are mechanical differentiation as things that are not mechanical differentiation. If the fictional position determines which mechanics may be feasibly used, the setting of DCs, which resources can be expended, then we can say that it is mechanically different from another fictional position.
While we are on the subject of computers, what do you know about state based machines?