But then what are we discussing when we say SC? If the structure is thrown out the window then we're basically saying skill checks however you want to do them, which I have no issue with but then there's no distinction in calling them SC's specifically...
EDIT: I mean isn't it the structure that creates the finality that many find are one of the SC's greatest benefits?
No, the main thing that defines a skill challenge is that it's a noncombat challenge worth xp. The structure of the challenge itself can vary tremendously, and over the life of 4e the published examples did vary tremendously.
So the big thing was formalized difficulty and XP?? Ok, I guess I can see that... but without the structure that falls apart doesn't it? It's the structure of the SC that allows you to get those values...
No, the structure doesn't matter so much, outside of the basic "How many successes do you need?" part, which determines the xp.
Let's take a couple of examples.
There's an example that was posted online and later made it into the DMG2 about sneaking around a slaver city, with the number of failures determining how alert the enemies are to the pcs' presence in the city. This isn't a "you fail at 3 failures" SC; it's more "the better you do the easier the rest of your mission will be." This is a vastly different beast than the "x before y" approach.
Another way a skill challenge could work would be not to determine success or failure, but
how long does it take to succeed? I ran a great SC in my 4e game where the pcs were looking for a half-sunken yuan-ti ziggurat in a swamp. They couldn't fail out of it, but until they got enough successes, they couldn't find the ziggurat in question. (Failures resulted in complications, and to be fair, the yuan-ti Indiana Jones and his pals were excavating the lowest levels in hopes of performing a nasty ritual, so if they hadn't eventually found it, there would have been consequences. But there was no 'failing' the challenge per se.)
Then there's the traditional "x before y" SC. Perhaps the pcs, trapped in the Underdark, seek to build a raft out of fungus to navigate an undersea river. Failing might mean that the pcs fail to build it at all or that the raft falls apart as they are on it.
There were SCs that allowed group checks- the slaver city one, or the trek across the Shadowfell desert in P1- instead of individual ones. There were SCs that allowed you to remove failures instead of just building successes. I never ran a SC as "only these skills apply"- I always took the listed skills as "these are some approaches the group might take". If you were in a SC that used Diplomacy, Intimidation, Religion and Insight, but you came up with a good way to apply your Streetwise, awesome! Just before 4e released, there was a brief adventure that included an urban chase scene that was laid out, basically, as "let the pcs try whatever they want and adjudicate it." The defining trait of a skill challenge isn't "these skills apply" or "x before y", it's "This challenge is noncombat, but still has consequences for failure, and is worth xp for navigating through it without fighting."
