D&D 4E Showing the Math: Proving that 4e’s Skill Challenge system is broken (math heavy)

[2WS-Steve]

Don't misunderstand me - I'm not laying this at the feet of the playtesters at all!

My concern is that WotC probably played their cards so tight to the chest that of the dozens of playtest groups, very few actually had even the opportunity to test this. I think that many of the playtest groups were probably testing scenarios rather than the rules.

Cheers

I also wouldn't be surprised if this was out there but just never got used. These "make a bunch of rolls" skill systems have been around for a while in other games and always look much better on paper than they play in real life.

At the table you just change one die rill into several die rolls. That gets tedious.

What makes combat fun isn't just the die rolling, but the fact that every die roll is the result of a decision the player or DM makes -- and it's seeing the results of your choices that makes it interesting.

But the skill challenge system has, at best, one tiny decision: what skill do I roll? And that's an easy decision -- the one with the highest bonus that is relevant -- so it's barely a decision at all.

Players and DMs realize how boring this is quickly, and then don't bother with the challenge system in the future -- thus it never gets really play-tested. Even moreso if the challenge system proves to usually result in failure for some reason of mysterious math.

But the rest of the game works really great and is very fun, so people just ignore the parts that need more thought.

 

[Larry Hunsaker]

I do not have my DMG yet, but I think I will define failure in a different way. Not sure if the skill challenge system defines failure as a non-success, but like 3E I would probably have 3 possible results, success, non-success and failure. Failure would be failing the DC by 5 or more. This would result in an instant failure. If you simply got a non-success, that is you failed but by less than 5, then that skill would have its future check DC increased by 5, but that non-success would not count as a failure. This would give a chance to redeem the non-success, but making it a tough one. Once you succeed in that skill, the +5 DC penalty is removed until another non-success results. So if you fail a check by 4 or less, you do not succeed nor fail, but if you try that same skill again, you have a +5 DC now, and that same failure by 4 or less would then result in a true failure, because the +5 DC would make that a fail by 9 to 5. This would alert the PCs that a particular skill has been pushed to its limit and further uses may be risky, and it lets lower skill PCs try it once with some cushion for a slight miss.

You could boost this DC failure to a failure by 10 or more to make it more forgiving, perhaps this would apply to skills that the Player who used the made an excellent role-play attempt, so you give him a deeper cushion of failure, giving more incentive to role-play.

 

[DSRilk]

I updated http://www.ebonterr.com/4e/skill_challenge_test.htm so that you can now specify the average char skill value, the challenge dc, as well as the number of required successes and max failures so that you can test virtually all scenarios related to skill challenges and find what works best for what you want to accomplish with a challenge. To work out things like easy checks that might give +2 bonuses, just figure out how often they're likely to occur. Just once? Then basically ignore it. If the chars could get that bonus for about half the checks, add 1 to the char skill value. If they could get it for every check, increase the char skill value by 2. Enjoy! And yes, the UI is ugly -- I won't use it enough to make it pretty

 

[Larry Hunsaker]

Another idea I am toying with is to use the system as is, but to allow for other PCs to aid the primary PC in each skill check made. The primary PC is the one who makes the check. If he fails, the other PCs can then try to assist him to recover from failure. This is a retroactive aid other, and the DC to make it would be 5 lower than the primary check DC. If the first assistance makes the reduced check, he gives a +2 bonus to the primary PC check, and if this is not enough to succeed, the next PC can try. But this cascade of skill assists stops once the first PC assistant fails, after that, no additional help can be offered. So as long as the assists succeed, the primary PC keeps racking up +2 bonuses and perhaps (if he did not fail by too much) his initial failure may become a success thanks to the help of the party.

 

[silentounce]

I updated http://www.ebonterr.com/4e/skill_challenge_test.htm so that you can now specify the average char skill value, the challenge dc, as well as the number of required successes and max failures so that you can test virtually all scenarios related to skill challenges and find what works best for what you want to accomplish with a challenge. To work out things like easy checks that might give +2 bonuses, just figure out how often they're likely to occur. Just once? Then basically ignore it. If the chars could get that bonus for about half the checks, add 1 to the char skill value. If they could get it for every check, increase the char skill value by 2. Enjoy! And yes, the UI is ugly -- I won't use it enough to make it pretty

The fact that we require something like this to determine how to modify the RAW so that the PCs can actually succeed at a decent, and fun for the game, rate pretty much proves that this system is broken. Honestly, I doubt they'll do anything about it, because there's not an easy or quick fix to make it less wonky. It'll be interesting to see how, if it all, WoTC addresses this in an errata or reprinting. The fact that the probabilities already existed in a previously published supplement and they still messed it up is somewhat amusing and disturbing at the same time. Surely, they would have used that for a reference.

 

[DSRilk]

...pretty much proves that this system is broken...

yes, it is

...there's not an easy or quick fix to make it less wonky...

yes, there is -- change the # success = 2 x failures to something more reasonable -- like X successes or X failures. Play around with the page I made and you'll see there are several easy ways to fix this.

 

[silentounce]

Can you make one change like that will work in a consistent manner for parties of different levels like the system is supposed to work? Judging from comments in here and in the thread that the OP linked to, probably not. I'd rather not have to go to your webpage and plug in a bunch of info every time and tweak it in order to get an appropriate challenge for my party. That's not a quick fix.

One of the big problems is the swinginess/variance, and simply changing the number of successes to something more reasonable doesn't fix that.

 

[DM_Blake]

It looks like all the math in this thread points to the RAW chance of success being in the teens, or twenties. So, around 20%, plus or minus for situational mondifiers and mathimatical variations.

As for me, I would prefer the chance to fail was around 20%

Therefore, I'm pretty sure what I'll do is simply reverse the success to failure ratio. For example, instead of 4 successes before 2 failures, I will probably go with 2 successes before 4 failures.

That way I can leave the RAW completely alone. I can stay with the DCs as presented and use the examples provided. All I have to do is swap the number of successes for the number of failures.

This way I will even be able to use any officially published dungeons without having to tweak DCs or muck with the challenge in any concrete way.

The only thing I don't like about swapping the ratio is that it will result in many challenges being over with just a couple skill rolls. It won't involve the whole party. So it's likely that I will take most skill challenges that only require 2 or 3 successes and I will double (or something like double) both the number of successes and the number of failures (which, interestingly enough, works out pretty much the same as just quadrupling the original number of failures without swapping the ratio - which may also end up being what I do much of the time).

 

[Tervin]

It looks like all the math in this thread points to the RAW chance of success being in the teens, or twenties. So, around 20%, plus or minus for situational mondifiers and mathimatical variations.

As for me, I would prefer the chance to fail was around 20%

Therefore, I'm pretty sure what I'll do is simply reverse the success to failure ratio. For example, instead of 4 successes before 2 failures, I will probably go with 2 successes before 4 failures.

I would not recommend that. It will lead to even weirder results, where higher complexity leading to over 90% and probably be even harder to get good numbers out of.

I set up a simple Excel sheet for calculating skill challenge probabilities, and the data from that says that you should set the DCs so that the players on average need to roll 5 or higher.

That gets the following results:
Complexity 1 0.73728
Complexity 2 0.79692
Complexity 3 0.83886
Complexity 4 0.87016
Complexity 5 0.89430

Attaching the sheet in case somebody wants to play with it. Regrettably it can't handle skill challenges outside the five normal complexities - that would make the formulas a lot more complicated...

(If the sheet looks weird it could be that it was made using a Swedish version of OpenOfficeCalc...)

 

[LostSoul]

but "no" it's still irrational that higher difficulty challenges end up being notably easier than low difficulty ones.

Except that higher complexity challenges aren't supposed to be more difficult:

"Set the complexity based on how significant you want the challenge to be."

Complexity is about real-world handling time, not difficulty.