Skill Challenges:
For the reference of anyone who has never heard of the concept, Skill Challenges are a mechanic that existed first and last as RAW in 4th edition D&D.
For whatever anyone might see as 4th edition getting wrong, I think Skill Challenges were something that it got pretty right.
Here's a rumination on the topic by
Matt Colville.
I do not run Skill Challenges exactly as he describes them, but I do use them in very much the same spirit, and in concept.
Skill Challenges do not follow the same "flow", nor even quite the same rules, as "normal" narrative (non-combat) play. They're almost a bit like a mini-game all their own, so it's important that everyone knows how it works. Here are my rules and description of Skill Challenges:
1. I will tell you all (ooc) when I want to use a Skill Challenge, to determine the resolution of a particular situation. If you had other ideas that a Skill Challenge does not facilitate (like, a very specific plan, that requires very specific/zoomed in actions, and depends upon or creates specific narrative positioning), just tell me, and we can pursue that.
We don't have to use them.
2. You may only use Skills (or applicable Tool Proficiencies) in a Skill Challenge.
OR if you have a narratively applicable Class Ability, or Virtue, or Wondrous Artefact, etc.
that consumes a Long Rest-only replenished resource (i.e. HD, per LR abilities, etc.), you may expend a use of that ability/item/resource for an automatic success.
Skill Challenges are meant to be used as a kind of middle ground between fully "zoomed in" narrative play, and just glossing over a scene with exposition. Like a training montage, or long travel sequence, or a getting the gang together sequence, or something in a movie that would be presented in a montage. They usually encapsulate hours if not days of time (though conceivably can be used for lesser time spans), and so that's the broad narrative justification for why it's Skills only. Moment-to-moment stuff is too passing to impact the overall outcome, what matters is longer term, consistent performance.
So that's rule no. 1, only Skills (or Tools, or resources - heretofore referred to just as "Skill") may be used. No combat checks or abilities. No factoring in abilities that might give one-off Skill buffs, etc. "Naked" Skill bonuses only, because of the amount of time and wide variety of things done, that the Challenge represents. - Plus this makes naked Skills more important, which is generally good for D&D, imo.
3. Every check in the Skill Challenge has a fixed DC, and that DC is 8+the average party Proficiency Bonus, +1 or more depending on the narrative difficulty of the situation (like, if you're up against much greater numbers, or opponents who are much more skilled than you? Those would be narrative considerations that would add 1 or more to the beginning DC).
That initial DC goes up by +1 after every 3 Skill checks rolled by the group. This creates an increasing tension and pressure, dramatically, and introduces a small element of mechanical strategy.
4. The success or failure of the Skill Challenge as a whole is then based upon the aggregate number of successes or failures the party achieves, together.
The default number of individual successes required to achieve overall Success, is the number of party members acting in the Skill Challenge. That is considered a narratively "Easy" Skill Challenge.
A more difficult narrative challenge will increase the number of aggregate successes required to achieve overall Success. For example, traveling across a hazardous but non-hostile land could be an Easy challenge. But a challenge where you must convince an authority of your innocence when they are already convinced of your guilt would be more difficult.
The number of Failures required to achieve overall Failure, is ALWAYS equal to the number of party members acting in the Skill Challenge.
5. From there, each PC chooses a Skill to roll, to represent how they contribute to the success of the Challenge.
The Skill must be able to be plausibly spun into the narrative given the challenge, as an effective way to contribute.
Every PC must have rolled once, before any single PC can roll a subsequent time each "round" (no piling all the checks on your skill-monkey).
AND no PC may use a single Skill more than once in the entire Challenge. (Different PCs can use the same skill someone else has used, but one PC gets one use of each skill they choose)
Annnd... that's basically it!
When a PC takes their turn to roll their Skill, THEY describe the narrative of that skill use, and how it fits into the narrative of the challenge, and they even narrate what their success/failure looks like in that context.
We go through a round with each PC rolling, before going back to the "top" of the order (or they can change the order) round-to-round, until the necessary amount of success or failures has been hit to determine how the Challenge went.
6. Now what does Success or Failure of the overall challenge actually MEAN, or look like in the narrative?
The DM dictates and describes the result of the Success or Failure of the Challenge as a whole, in advance. I will give you an idea of what Success and Failure will both look like, before we begin the rolling.
Skill Challenges will almost NEVER have a binary pass/fail, live/die result.
Failure will usually cost one or more resources. This could mean inflicted damage. Or cost in gold. Or inflicted Conditions. Or expended HD. Or expended Inspiration. etc. and almost always it will mean worse narrative positioning going into the next scene.
BUT, Failure will still leave the party a path forward, and not present a dead end, nor TPK, nor a narrative position that makes all the work you just did pointless/requiring you to go somewhere else and do something else.
Furthermore, overall Success results may still include some lesser degree of expended resources, and/or some lesser degree of complication to the narrative.
The point of Skill Challenges is to move a little more quickly through a less important scene (to de-emphasize micro-managing the resource attrition game), so that we may get into the actually important scene (while still having introduced character attributes and resource depletion).
The biggest thing is often how the Challenge places the PCs in the narrative.
Did the enemy discover something about your effort, and how much?
Are you "dumped" from the challenge directly into an ambush, or do you have a moment to prepare?
Do you arrive at your goal exactly where you wanted to be, or are you a bit off course?
So on.
And then pair those thoughts with the mechanical resource impacts.
7. Furthermore, the overall success or failure of a Skill Challenge (note: NOT the individual checks) can use the "Success With Complication"or "Degrees of Failure" rules when determining the overall outcome/consequences.
If you get 5 successes in a 6-success Challenge, but still Fail, maybe there is a middle ground between the bad and good of failure and success?
Statistically, you'll basically never have "complete failure" where there are no successes rolled before complete failure (again, it's always "party count" failures to fail), BUT it could conceivably happen if you're really unlucky. And so a "complete" failure may be EXTRA bad.
Annnd... I think that's REALLY about it.
What we end up with is a way to give mechanical importance to sections of the narrative that we may not want to spend too much time on (or, usually, narrative where round-to-round play could be completely invalidated by the recuperative Resting rules), but that we want to carry some mechanical weight/significance, and to have some impact on the story, and to thereby bear importance to the campaign.
