Quote Originally Posted by Doug Lampert View Post
I'm not stoutstien, but, in 5th edition there are three types of rolls, ability checks, saves, and attacks. Some rolls of each of these types get to add the character's proficiency modifier.

There is no such thing as a skill check. It simply does not happen in the rules.

There are ability checks where you get a bonus of being allowed to add your proficiency modifier because you have a relevant proficiency.

The baseline values for "how hard is this ability check" should be set based on the ability scores characters are likely to have. Any added bonus from proficiency is a bonus and should make success more likely rather than making you increase the DC to compensate. When figuring a DC, 15 is "the best in the world succeed at this on a roll of 10 or higher without a special bonus", because proficiency is a special bonus to an ability check, and this is an ability check, not a skill check.
Quote Originally Posted by stoutstien View Post
Basically this.

Now if they didn't go and break this relatively good design principle left and right I would wager the complaints about ability checks would be limited to to those who would be better if not playing a open ended action resolution system to begin with.
Thanks for the clarification, that makes sense. I hadn't thought about it in those terms, but I think I end up in the same area by tying the checks to how I think it relates to a commoner. The idea that the best in the world at something would not have proficiency in it gives me a bit of heartburn, but that doesn't change how I would set a DC. For me, I don't think about the best - I think about how likely I think it should be for a commoner to do it. If a commoner will do it every time, DC 0. If they can do it half the time, DC 10 (should be 11, but, hey, round numbers). That makes natural talent worthwhile, but not controlling, I think - someone with a 20 strength but no proficiency is twice as likely as a commoner to do a medium-difficulty thing, but someone with strength who has practiced the thing could be good enough to not even need a roll, or someone without the strength but has practiced may do as well as the naturally talented.