Pre 4E your character is capable of being a cause and you then find out what effect is the result when that cause interacts with their surrounding.
Although this picture might be attractive aesthetically, I think it has fundamental flaws. The problem is that there is nothing for the "cause" to have effect
on. The only "effect" being generated is on the minds of those playing; the effect of the pre-4e rules is that the players have a picture of what has happened supplied, but no clear idea of its implications. The 4e model, on the other hand, makes clear how the actions done have affected those in the world, and the implications of those actions for the future actions of the characters, while leaving the "picture in the head" element purely to the participants.
This works immediately for those pursuing "gamist" aims (i.e. players using their own intelligence to direct their characters in ways designed to overcome in-game challenges that are inimical or indifferent to them). It does not work so well, immediately, for those who seek more subtlety and occlusion in the implications being generated. But, then, I don't think the "paint a picture" systems did that any better - the implications were merely put into the "too difficult" tray and left as an exercise for the reader (i.e., generally, the DM). This can work out in the end if the DM can produce results that satisfy the aesthetic desires of the players - the DM as "entertainer", in effect. It can also work if the GM and the players collude (which is to say actually communicate, not have the players merely assent or dissent on the GM's decisions) to produce outcomes that suit them all. But, in no sense is there a pre-set "reality" which is being explored (a common belief, I find); if anything, what is being explored are the overlaps and dissonances in the players' imaginations.
I also continue to find it amusing how it has become so in vogue with the 4E niche to praise 4E in terms of being unique and completely different than prior versions. A few short months ago any slight hint that 4E was a different game than prior versions was a mortal sin and insult of the lowest form.
You may be right in general, but I don't think I have ever contended that 4e is "the same" as older editions. Indeed, the differences are why I much prefer it to older editions. I may have said it can
do some things that fans of older editions have claimed that it can't - but I think that's rather different.
I'm trying to understand this, and not really groking it. Could you give me an example of a pre-4e action or effect where the fluff was detailed but the mechanics vague?
Sure. Take, for a start, the "Phantasmal Forces" spell in pre-4e. It gives a lovely description of what it looks like - how many humanoid figures, what volume in space and so on - but not one word about how this might affect the world or NPCs in it. Does the lack of smell and sound mean disbelief is almost a certainty? Suppose an illusionary bridge is set over a real chasm; how do creatures that know there was no bridge there last week respond? Does a creature that tries to cross the "bridge" get a reflex save to avoid the pit, much as a character might do if the floor gave way in a pit trap? None of this is even mentioned.
Example 2: Charm Person. The target "treats you as a trusted friend" - what does that mean? If you attack their other friends, does it mean they will join you in attacking them? Or will they attack you to subdue you and stop you hitting friends (as you are obviously affected by inimical magic)? And what happens after the spell ends? Does the target know it was charmed? Or does it rationalise what it did while under the effect of the spell? Again, we get a nice, evocative description of what being under a charm spell
feels like, but nothing in terms of what actual effects it can have on the world.
For me, what is missing - and what will always be supplied in some form - is a model that describes how the effects described in the spells (and it is, almost always, spells) play out in the world. One poster on WotC's forum, for example, has experience with hypnotherapy. When DMing, they use their experience there as a model for what Charm Person will do. All DMs who have the spell turn up in their game will, necessarily, come up with some sort of model - be it detailed and carefully thought out or rough and quickly thrown together. If subtle and occluded implications are to be a part of the game, I would much rather see these models actually detailed (or at least discussed) in the system document. Leaving them up to the GM is, to me, just lazy design - putting it into the "too difficult" tray. In the earliest editions, this is forgivable - the authors themselves were only just exploring the ground - but in a modern ruleset it's just shoddy, in my view.