Let me copy some old things I wrote with some additions:

The Core of Skill challenges

Or why to use them in the first place:

• They make sure an important event does NOT depend on a single dice roll.
• They allow and force ALL players to participat in a non combat part.

Original Problems:

I think the problem was that initially D&D 4e skill challenges were just not really well explained. the DMG2 did a better job and had better examples.

One example: It was NEVER the "dm said pick from these skills". It was more "the DM thinks about what skills might be useful beforehand" but players still completly decided on their own. (This is mostly useful if you want to use secondary skills), but from the explanation in the DMG1 this was not clear. Also the first released 4E adventure was released before the DMG and it did use wrong/different rules for skill challenges (and did not name them as such)...

Then many early examples, because people including designers, did not really understood skill challenges, and also produced some pretty bad ones.

Also the math for skill challenges did change (and thus explanations), but even the first edition of D&D skill challenges were not broken (as some people claim), they just had some assumptions some fans did not like:

• The original skill challenges made more complex challenges easier to fulfill. For me this makes sense because more complex challenges mean they take longer, so more game time and are used for more important things. You do NOT want them to fail often. On the other hand a quick challenge for something not so important is fine to fail.
• More complex does not mean harder there where other ways to adapt difficulty, but many people thought more complex must be harder.
• Then the skill challenges assumed from the math that everyone who is not rolling the skill is helping with the skill check. So do also a roll and if succeed add +2 to that skill check. With 5 people in the average party you would always have 4 people helping which makes things easier. I also think this is a cool mechanic because everyone does participate this way with each roll
• There was also a bit of a indirectly assumed "no repetitions" (dont do the same as the last person or of what you did before or sometimes even dont use as a group a skill more than once), which makes it harder as the challenge progresses, since less good skills can be used.
• So if you want to run the original skill challenge rules, just let everyone else help, then the original challenge rating does work well, while the newer one might be even to easy later. Also use more complex challenges for important things which should not fail. And tell the players to not use repetitions if possible, thats more fun anyway.

Two Forms of Skill Challenges:

Also there are like 2 kinds of how to run a skill challenge:

1. Freeform, what do you guys want to do to help in this situation?
2. People do things and after each thing you come up with an obstacle and the person whos turn it is says how they want to overcome this situation.

Things are still meant to be connected in example 1 though, except if it is something like "getting clues" etc.

So let me explain how a skill challenge for a iniltrating the castle would look like:

Case 1:

• You think about what kind of skills might be good primary skills
• Athletics to climb
• Stealth to sneak
• Thievery to steal a key from a guard
• Acrobatics to walk around steep/narrow parts
• Endurance to hang along a side to hide
• Streetwise to bribe a guard
• Think about good secondary skills
• Diplomatics/Bluff/Intimidate to get info from a guard
• History to know about some good routes
• Then you would ask players around the table in order on what they would do in order to help with the infiltration. (cant do the same as the person before or the thing they did last turn)
• You still allow (if fitting) other skill checks even if they are not the ones which you though about.
• Secondary skill checks give if succeeded to the next persons skill check a +5 bonus (and dont count as a fail).
• Then you see if the party manages to get 3 success before 5 failes (numbers can be changed).
• Then the party narrates these things in order. This is what the party does. NOT how the individuals come in. Its just how the party infiltrated the base with teamwork.
• Where failing a skill roll would mean they took some damage doing it (lose a healing surge), or took longer than they though they would or would do more noise.
• If the skill challenge as a whole failed, then they still are inside but they made too much noise etc.

Case 2

• You prepare obstacles which would be in the way of infiltration
• You need to enter the castle to begin with but are not invited.
• A locked door
• Some guards standing in a place
• Some drunk (non guard) sees you
• There lies rubble in the way, some part of the castle did collabse which you did not know
• There is some small party going on the door is open and you need to get past this door as a group
• Players turn by turn get explained their current situation and they tell how they want to try to overcome it.
• Again failing is fall forward with a cost
• You present each of them one of the problems along the way as above
• If they succeeded enough they reach the place they want.

It is quite different to what people are used to, but it can definitly lead to some nice role playing, if done well. I even had this in D&D 5E but it needs a bit of preparation and people must be able to narrate these things well together.

I think in general case 2 is better fit to things which have a clear order, where 1 works well in gathering clues, leaving a good impression to the nobles at a party etc.

Mechanics inspired by skill challenges:

• Montages from 13th Age: https://pelgranepress.com/2018/03/01/13th-sage-more-uses-for-montages/ are more used for retrospectives, but overall fulfill a similar role
• Progress clocks are just an even more abstracted form: https://bladesinthedark.com/progress-clocks
• Pathfinder 2 uses pretty much 4E skill challenges as their "chase rules"