Hmmm... why tell them the DC?
And how is that a problem, that's pretty much just the resolution system, except for not calling for a specific check...
Right... but it's usually pretty easy to work out what skills apply. The only difference this really makes is whether the player talks the DM around to a different skill being used, or whether the DM just randomly made things much harder because he didn't decide on an applicable skill and the skill rules don't actually say to change DCs based on that...
Good CHA and proficient in Deception? Not too likely to fail a DC 10.
20% is plenty if the consequences are bad. The DMG has very little advice about consequences except to say that they might be one reason to call for a check instead of allow automatic success.
Certainly not if he's a rogue or bard with Expertise in it. I suppose at first level, but nothing's 'easy' at 1st level...
A rogue or bard with expertise is still sitting at a 10% failure chance. Which is better, to be sure, but bear in mind we're now talking about only two character classes, in their focussed skills with the best available stats in place, still failing at an 'easy' task.
Also that first level is actually "1-4th level". Our friend the super-specialized, maxxed primary stat rogue or bard won't get to 100% surety until he hits 5th.
Finally - in what bizarro world does a non-scaling difficulty system that says a task is 'easy' not actually mean a task is 'easy'? That's the sort of poor communication I'm talking about.
Wait, how does a rulebook do communication for you? You mean because it might contain actual, functional rules that cover most situations without reference to the GM, so everyone at the table knows what their characters are actually capable of?
That's a possibility. Or it could have 'easy' checks that are actually 'easy' rather than 'the best possible character at this check still fails 10% of the time with no confounding factors'.
You also don't really get a hint that you're supposed to have that conversation (and, I'm not convinced you are: the player is supposed to the declare an action, the DM to narrate success/failure or call for a roll - nothing about explaining that decision to the player).
I'm personally not surprised that the game isn't self-aware enough to realize that it's rules necessitate this.
5e, IMHX, plays well 'close to the vest,' take all that behind the DM screen and narrate what happens as a consequence. Heck, making rolls in secret can work better than calling for them anytime there might be a surprise in the consequences of success/failure...
Right, but that just ends up with characters walking into a room and failing what is described as an easy task because the DM decided a roll was necessary because of 'consequences' and assigned an 'easy-but-actually-fairly-risky-if-you-think-about-it' DC, then rolled against it and failed. You've just hidden the final numbers, not the result.
Now there are games - like, what-is-that-indie-game.... Blades in the Dark, Powered by the Apocalypse system, I think - that do walk you through about that kind of conversation. What are you trying to do, how are you trying to do it, what are you putting at stake to get it done, etc... making the players more like authors of the story.
Right. But even previous editions of D&D did a better job at making DCs conform to expectations, through the devious mechanic of simply making a starting trained character have a high enough modifier to automatically succeed at an easy DC.