And that lead me to this silly little thought. Picture this:

The PCs have to navigate an underground river through the underdark with no light. You announce that it’s time for a skill challenge and you…

…

(wait for it)

(wait for iiittt……)

…break out a chess board and start setting some pieces on it!

Things look bad for white. Black is 3 moves away from checkmate and still has most of its pieces, while white’s forces are anemic and under assault.

Now, every time a PC gets a success in the skill challenge, that player moves a piece for white. Every time a PC gets a failure in the skill challenge, the DM moves a black piece. If White is checkmated, the PCs fail the challenge and if black is checkmated the PCs succeed.

1. Come up with an idea. This is probably the broadest and least helpful part. Sorry! A skill challenge can really be almost anything short of combat, and it can take place over the course of days or weeks or it might be something the PCs need to deal with in the middle of a raging combat.
2. Figure out the limits. A skill challenge will have limits to the number of checks that can be made. These limits should flow naturally from the idea. Some examples might be…
   1. Time limit: Some vents must be disabled before knockout gas fills the room. A stuck portcullis needs to be closed before the marauding orcs reach it. Time-limited skill challenges are excellent opportunities for getting the whole group involved, since more people making checks means more checks get made in the limit amount of time available. Thus, when designing a time-limited skill challenge, try to throw in opportunities for a diverse set of skills.
   2. Failure limit: Maybe they only have three Magic Orbs of Xinthos and each time the warlock fails an arcana check one of them shatters, or the prince will become infuriated and send them away after five failed diplomacy checks. A challenge limited by failures will probably only be attempted by the character with the best check in the relevant skills, and smart players will make judicious use of the aid another action. If you want to encourage multiple characters to contribute to the challenge, make skills limited so that they can only add one or two successes. It might also be a good idea to make the DCs a little harder and encourage PCs to use aid another if they’re not already.
   3. Skill check limit: The PCs are trying to influence the ruling council, and get one skill check for each member. This approach works best for a challenge with levels of success and failure (see below). It also has many of the same features as a challenge with a limit on the number of failures, so all of that advice applies here as well.
   4. No limit: No limit? How can we do that! Like I said in the first rule of failure: failure is not possible if the PCs can keep trying until they succeed. Well, I also said there was some subtlety there, dammit. This works fine is there’s an open-ended penalty for each failure, such as being delayed a day.
3. Figure out the consequences. This is the most critical part. Decide what happens if the PCs succeed at every check, and what happens if they fail at every check. Depending on the circumstances, you might have a situation best served by a simple binary fail/succeed paradigm, in which case you’re done, or from there you might be able to branch out into degrees of success.
   1. Fail/succeed: The simplest option. Either the PCs fail or succeed, black and white.
   2. Levels of success/failure: Depending on how many successes or failures they get, different things happen. If they’re interrogating a prisoner, for example, each success might correspond to a different piece of information. When researching a demonic entity, each failure could mean being set back another day.
4. Choose skills. Some skills will follow easily from your idea, but don’t just take the low-hanging fruit. Look for opportunities to inject other skills in there, too, particularly skills not often used often. It’s also not as simple as just making a list. You should decide what happens with each skill, and any limits you might place on them. Here are some ideas to spice up your skills:
   1. Unlocked skills: A skill is not unlocked until some task has been fulfilled (frequently, making a particular skill check). For example, an arcana check may reveal that the runes are not magical, but they are of some historical significance, opening the way for history checks. You can, of course, come up with other ways for skills to be unlocked, such as killing a monster, failing a number of skill checks, or after a certain amount of time passes. The DC for an unlocked skill is frequently easier than other skill checks in the challenge.
   2. Give bonuses: One skill check might give bonuses to later skill checks. You might even have skills which don’t contribute directly to the challenge at hand, but do give significant bonuses to make the challenge easier overall.
   3. Allow extra failures: In a challenge limited by failures, this can give the PCs some breathing room.
   4. Add time: Similarly, in a challenge limited by time, this can also give the PCs some options if things are looking bleak.
   5. Limited successes: Sometimes, it makes sense that a skill can only get you so far into completing a challenge. It’s also a great way to help mitigate the problem of the group’s skill monkey treating the skill challenge as a solo affair.

So, do you have any tips for designing skill challenges?

Ultimately, it was just too ambitious. You can’t hope to make a framework that will cover all non-combat situations equally well.

That said, if we distill skill challenges to the most basic essence, it’s still a good idea. And that most basic essence is this: Make something dependent on several skill checks instead of just one.

Now, that said, there are three rules that I’ll go out on a limb and say do apply to every skill challenge.

1. There must be the possibility of failure. There’s some subtlety here, though. For example, failure is not possible if the PCs can keep trying until they succeed.
2. There must be a consequence for failure. In the most abstract terms, this means that the PCs are tangibly better off if they’d made every roll than if they’d lost every roll. This doesn’t necessarily mean something bad has to happen if they fail, though. For example, it might be that rather than something bad happening, something good doesn’t. Six of one, half a dozen of the other.
3. Failure must be an option. Just generally good advice. If you ever find yourself planning something that the PCs simply can not afford to fail at, then you’ve failed at planning.

If there’s no possibility of failure, there’s no reason to roll the dice. If there’s no consequence for failure, there’s no reason to have the skill challenge in the first place. If failure isn’t an option, then you’re setting yourself up for having to choose between fudging things and railroading the PCs into what you need to happen or completely ruining your game.