D&D 5E Skill challenges in 5e - Math help!

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[MENTION=42582]pemerton[/MENTION]
Thank you for all the number crunching! You beat me to it! I'd XP you if I could.

You confirmed what we, or at least I, suspected - that skill challenges can't be directly ported into 5e because the math is different and there is more magic swinginess built into the system, not to mention PCs helping each other (and all the other ways they might gain advantage).

I think the assumptions in a 5e skill challenge would have to be:

• The odds are built around PCs with skill boosting magic, Expertise, and/or ways to gain advantage.
• Easy DCs should be the backbone of the challenge. Easy DCs aren't necessarily "easy", but are easy relative to the overall difficulty of adventuring tasks that aren't assumed to be automatically successfully. IOW if its worth rolling then there's a significant risk of failure.
• You probably don't want super long (e.g 10 or 12 successes required) challenges in 5e. My guesstimate is that requiring about 7 successes is the maximum practical limit. Of course, changing the failure limit is always an option, but if you're willing to change the failure limit, that breaks the math.

 

[pemerton]

Thank you for all the number crunching!

No worries.

I think the assumptions in a 5e skill challenge would have to be:

• The odds are built around PCs with skill boosting magic, Expertise, and/or ways to gain advantage.
• Easy DCs should be the backbone of the challenge. Easy DCs aren't necessarily "easy", but are easy relative to the overall difficulty of adventuring tasks that aren't assumed to be automatically successfully. IOW if its worth rolling then there's a significant risk of failure.
• You probably don't want super long (e.g 10 or 12 successes required) challenges in 5e. My guesstimate is that requiring about 7 successes is the maximum practical limit. Of course, changing the failure limit is always an option, but if you're willing to change the failure limit, that breaks the math.

I agree with your first dot point. Those sorts of assumptions would, in a functional sense, take the place of "advantages" (from Essentials) in 4e skill challenges.

I agree with your second dot point, too. Moving the DC from 10 to 15 has a big effect! That said, you might want guidelines for gradually stepping some DCs up to 15 as the PCs gain levels, because otherwise the maths will break down at those higher levels. (4e solves this via "treadmill" scaling). I guess at 20th level, when all the proficiency bonuses are 4 higher than they were at 1st level, plus everyone has some stat gains under their belts, you could say all DCs go to 15. I'll leave you (or someone else) to crunch the numbes on this for all the levels in between 4th and 17th.

On your third point: You want enough rolls to be interesting and give time for complication to emerge/transform and then be resolved. The highest number of possible rolls in 4e is 14 (12 successes after 2 failures), not counting rolls to undo failures, aid another etc.

For 5e, I think it would be worth checking success rates using 4 failures rather than 3 failures as the norm: then I would suggest 4, 6 and 8 successes before 4 failures as the options. (The other benefit of 4 failures is that it makes it easier to set up a die - d4 - as your failure counter.) That gives a maximum number of possible rolls as 11 (8 successes after 3 failures) which seems reasonable to me.