The basic dynamic is very similar: I as GM frame the situation, the players engage it via their PCs, skill checks are made and resolved, I renarrate the situation in light of that, and the process continues until either N successes or 3 failures is reached. The trick to the narration is to (i) keep the scene alive, so that the players continue to engage, but (ii) be able to bring it to a close at the requisite time. A good sense of both the evolving fiction, plus various complications that can be introduced to push things in the appropriate direction, is important to running these encounters.
As I just said in another thread (and in a reply to you), I like the X successes before 3 failures rule, as long as each failure introduces a complication, and as long as the in-game fiction keeps moving between each check. I think 4e usually hits these goals.
However, I do run my differently from you. I, as GM, call for what the next check will be. And, it usually won't be immediately after the next check. And, I also don't make everyone participate (the best goes when applicable, and the worst when applicable).
For example, if they're trying to research, then infiltrate a castle, and then convince a king of something, it might look like this:
(0) Fictional setup in-game already established. Plan established. Skill challenge begins.
(1) I'll call for a Knowledge check first for researching. If they succeed, it'll be one success on the skill challenge.
(1a) The interaction from there continues, and convincing the guards to allow them into the castle will generally not be towards the skill challenge.
(1b) Speaking to the chancellor might be, but may not be, depending on whether anything even gets rolled.
(2) The second check may not even show up until they speak to the king, where they try to convince him using the Negotiation skill (modified by the Empathy, Sense Motive, Leadership, and Knowledge skills, maybe the Intimidation, Bluff, or Perform skills, rarely other skills [like Appraise, Assess, Disguise, Martial Prowess, Tactics, etc.], and stunts).
(2a) Depending on how much he buys into it (he may go for it from the start, even before the skill challenge ends), the challenge continues. If he bought into it, his advisers might begin to attempt to convince him not to follow through, or to go through with it in a way that doesn't work for the PCs, or to stall until they can coordinate the effort better, or the like.
(2b) Depending on their success, we either have the king altering his plan, and the PCs trying to convince him again (harder than before if the advisers succeeded), or convince the advisers.
(3) Depending on the PCs' choice, I might call for a Knowledge check to know about their personality, or a Sense Motive check to figure out what they value in this conversation (so they know what to appeal to).
(4) As of this point, I might ramp the tension or excitement up a little by following an actual skill challenge check with a second one (Negotiation check, again augmented by the same set of possible skills or stunts).
And on it goes. I didn't account for complications that might arise from failures, but complications can arise even via success (the advisers trying to change the parameters of the success). I find this to make for a dynamic fictional outcome, and one that is unpredictable in most cases (something I also want it to produce for me).
I think, personally, that calling for the checks as the GM (based on what they players say they want to do) is important for dynamic and fun skill challenges. Players can certainly think "I want to convince the king", and tell me "[to the king] Your majesty, we're just trying to keep your kingdom safe by aiding you in your cause against the goblins*. If you give us twenty-five knights, I think we can clear out the goblin cultists we've found." In such a situation, I don't deny the player his Negotiation check, but I do decide whether or not it applies towards the skill challenge's successes.
*(As an aside, I don't have goblins in my game currently, so it's obviously just an example.)
There is also the need to apply "genre logic" in adjudicating players' declared actions...
Second, they have nothing analogous to the "genre constraint" on permissible actions. So there is no simple mechanic for (for example) evaluating the success of a dwarven fighter-cleric's attempt to facilitate the reforging of an artefact by shoving his hands into the forge and holding it steady...
I don't think this sort of improvisation is so easily incorporated within a system that relies heavily on the mechanics themselves, rather than the logic of situation and genre, to determine what is feasible and what the consequences of actions are (and what makes this workable, in a skill challenge, is that the push towards resolution of one form or another is provided by the metagame imperative of the "N before 3" structure, rather than the mechanically-determined outcomes of discretely resolved tasks).
This seems like an argument for a rules-light system. I see the appeal, but I think it's not necessary for a good skill challenge system, personally.
For D&Dnext to support this sort of non-combat resolution, at a minimum it would need to give me DC guidelines, some sort of resource system able to play the same functional role as the power system in 4e, and a general approach to scene framing and scene resolution which allows "genre logic" and metagame-driven complication introduction to work (so eg no need to track time and durations outside the context of the scene, which is one enemy of scene-based resolution).
I'd disagree, other than with your "this sort of" qualifier. It doesn't need those things in order to have a skill challenge system. It doesn't need to force everyone to participate, it doesn't need to define the skills usable at the beginning, it doesn't need to allow the players to decide which check will contribute towards the skill challenge total. Those are all fine, or even better, depending on play style, but they aren't necessary for an enjoyable skill challenge system (obviously for a different play style).
At any rate, I'd like to see some form of system in effect in a rules mod in the PHB (with advice on running them in the DMG, probably). They can definitely add to the game, from my experience, and while many people dislike them, I would like them around in some form. As always, play what you like
