As the original essay stated, all mechanics both abstracted and metagamed (emphasis added). The example given in the essay are players knowing that fireballs do (d6 x level) damage whereas characters have no idea what d6s are. The exact numerical representation of hit points or Strength or the DC of an Open Lock check would all be similar examples.
The examples that I gave weren't analaogous to knowing the DC of an open lock check, or d6 damage from fireballs.
To repeat them, they were: knowing that a 200' fall won't be fatal; knowing that a sword blow won't be fatal; knowing that one more blow
will be fatal. These are things that a player can know, that his/her PC
cannot know (assuming that the fantasy world resembles our real world in all the ways that the fiction presents it as doing so). This is not just about units of measurement, like DCs and d6s of damage.
Like I mentioned, I think it's important to note whether or not characters can investigate the reasoning in-game. If the reasoning for the ranger "Hide in Plain Sight" can be taught (or otherwise learned), explored, or observed, it's not dissociative. If the use of Evasion while sleeping saves a rogue cannot be taught (or otherwise learned), explored, or observed, than it is dissociative.
What does it mean to "learn" or "explore" how one hides, non-magically, in plain sight? Or how one "evades" an explostion, non-magically, while asleep? I'm not persuaded that we even have a coherent notion of what that would mean.
Yes, the game rules
assert that these are non-magical talents that can be learned. It could also assert that heirophant druids have non-magical techniques for squaring the circle. But mere assertion doesn't create the actuality of coherence.
Boromir could use it anytime it makes fictional sense, and he could theoretically do that when he wants and how often he wants. 4E wouldn't prevent Boromir from using the horn whenever he wants, but it may limit the number of times it has a consequential effect.
In the gameworld of 4e the rogue could, theoretically, do it whenever s/he wanted to also. It's just that s/he
doesn't.
You, the player, know this won't happen. Just as you, the author/reader of LotR, know that Boromir's horn usage will be reserved for dramatic situations.
Yes, it's metagaming. That's the
point of the mechanic. It doesn't follow from that that it undermines roleplaying and promotes tactical skirmishing, which is what Justin Alexander's essay claims.
The blog post isn't opposed to dissociative mechanics in general - rather ones that aren't worth the trade-off. Is the trade-off of bringing the player out of the PC perspective every time you use a dissociative mechanic worth the results? What result is the dissociative mechanic in question attempting to achieve?
In the case of 4e combat powers, the answer to this question is pretty obvious - it's to produce combats with dramatic pacing, and as an element of that pacing dramatic participation by all the protagonists, not just the Vancian casters.
Whether or not it succeeds at that is one interesting question - experiences appear to vary wildly. Whether or not using metagame mechanics to
achieve this result is desirable for everyone is another interesting question - apparently some RPGers really don't like leaving a very tightly circumscribed actor stance.
These are all interesting things that the original essay could discuss, but doesn't.