A +5 to hit a DC 20 and a +10 to hit a DC 25 can be a change in the fiction, but it's mechanically irrelevant.
To whom? Why? how was the bonus to hit acquired? If the bonus to hit is acquired by clever spell casting or ability stacking, and as a result a PC can hit not just the king's bodyguard but the king himself, I don't think it's irrelevant at all. Not in the fiction, and not mechanically - the increased bonus is a result of clever play.
That's all great, but it's your DMing skills coming into play, not how the game is written. In 4e, if I was designing a 5th-level adventure that included Vecna's Very Secret Diary in it (maybe it's in the same room as the MacGuffin) and I want the PC's to have a chance to open it, maybe I'll give picking the lock a hard DC...for 5th level characters. In 5e, that same diary would be a hard DC period. They've got a chance to open it, just as in 4e, but now that DC is a property of the item.
If later on in 4e, I've got a dungeon crawl and I want to have hard locks for the 10th-level party, I'll again use a hard DC. That'll make it harder than opening Vecna's Very Secret Diary.
If you pick Vecna's lock as a level 5 character, at a hard DC (because the story took you there) then it is hard to feel like when you're picking tomb locks as a level 10 character at a hard DC (because that's where the story is then) that you've actually gained much mastery.
As others have just said, this is bizarre.
If, in 5e, the GM describes a rusty lock and says "Hard, DC 20" and then describes a gnomish lock with adamantium tumblers and says "Simple, DC 5" that won't make sense either.
Why would a GM give one lock the same DCs as another lock when, in the fiction, they are not of the same difficulty? Why would anyone assume that the 5e GM, who can keep the relationship between fiction and DCs straight, would be unable to do so in 5e?
Even a DC that is high for a 5th level character will be really low for a character of 15th level in 4e. In 5e, these DC's are the same - hard is hard.
This doesn't make sense either. In 5e, as in 4e, a DC that a 5th level has trouble overcoming won't be hard for a 15th level PC to overcome. Both games have PCs whose bonuses get bigger with levels.
In 4e, these DC's vary with the level of the character - hard for a 1st level character isn't hard for an 11th level character.
Nor is it in 5e. In 5e an 11th level character has a better proficiency bonus, better access to buff spells, probably better magic items, better stats, better feats. Things get easier.
But it's up to the DM to determine what those DC's mean in the fiction, they don't have any inherent qualities.
No numbers have any inherent fictional qualities.
In 5e, the association between DCs and fiction is set, at least notionally, by the game designers. In 4e it's expected to emerge via play - that's the "rulings not rules" element of 4e. Both games take for granted the GM's ability to maintain a coherent fictional world. That's the role of the 4e GM in
adjudicating the narrative, which I quoted upthread from the 4e PHB.
So there's no reason presume that an adamantium dwarven lock or a rusty tin lock have ANY particular DC - they have the DC that seems relevant to the DM at the time, whatever offers the players that narrow band of success.
If this is how you played 4e, no wonder you don't like it!
There's no reason
inherent to the system, as published, to associate any particular DC with any particular lock. That's why the system can be used default, or to run Neverwinter, or to run Gamma World. That's why the same stats can represent steel weapons by default but bone weapons in Dark Sun.
But once the game is actually underway, the GM is absolutely expected to maintain fictional coherence. Thus, in Dark Sun, steel weapons have bonuses that they wouldn't have in default; in Neverwinter, upper heroic PCs are (in the fiction) more capable than default PCs of that tier, because Neverwinter uses monsters (and associated fiction) that compress the default 20-level experience into 10 levels.
Neverwinter mindflayers and aboleths are a signifier of what I'm talking about. If you save the world at level 7, when there's 23 levels left to go in the game, there's no mechanical accomplishment there, so it can make the fiction feel entirely empty of relevance.
Huh? Neverwinter is a 10-level campaign. That's the whole point (see the introduction to the book). If you want to run a default, 30-level campaign then you don't use the Neverwinter monster statblocks and associated fiction.
the DM could just declare that your characters are like unto gods and can kill demon kings on a roll of 4, and you aren't going to feel that accomplished killing demon kings because your ability to do so had nothing to do with anything you did as a player.
Is there some law of nature that prevents a 5e GM from starting his/her players at 20th level? Or that stops her from statting up a demon king as a CR 1 creature?
Which is to say I don't see the issue. If a 4e group wants to run 1st level PCs (they're mechanically pretty simple) but set the fiction as epic heroes vs demon kings, then go for it! I don't see that this is any sort of crime against nature or good taste.
The Rules Compendium even explicitly talks about this: "Some DC's are fixed, while others scale with level. A fixed DC represents a task that gets easier as an adventurer gains levels...In contrast, a DC that sales with level represents a task that remains at least a little challenging throughout an adventurer's career."
But it doesn't say that Vecna's lock is easy for 5th level PCs but super-hard for 20th level ones! Which is what you are positing.
5e just decided that its DC's are fixed by default
And this isn't even true of 5e. For condition-infliction, for instance, it uses scaling DCs (either opposed checks, for shoving, or proficiency bonuses to saves, for spells). And that is for the same reasons as 4e - namely, that making condition infliction mechanically easier as the game develops tends to make for bad gameplay.
Bounded accuracy means that you might go up against that dragon at level 11 or level 20 rather than level 17, if the story leads you there, and it will still be the same threat. It doesn't change into a lower-tier threat just because you're confronting it at level 5. That consistency is key for this feeling of achievement, because it means there's something to measure yourself against.
None of this makes any sense.
Some of it is just playing with numbers: I could double the range of 5e's levels - say at odd-numbered levels you get only HD, at even-numbered ones class features - and now I would have doubled the range of play at which that dragon is relevant - you can confront it at level 21 all the way to level 40! But that means nothing.
Some of it rests on bizarre assumptions that I would present
the very same entity with arbitrarily changing stat blocks, without regard to the fiction of the game.
Some of it seems to rest on an unfamiliarity with encounter building in 4e. In 4e, a monster as statted is generally relevant for a range of around 6 to 8 levels. (For my 30th level PCs I wouldn't use a monster below about 27th level, nor above about 35th).
There's no doubt that numerical scaling in 5e is less steep than 4e, but that doesn't bare any connection to "objective" vs "subjective" DCs - as other posters have argued upthread, you could adapt 5e to "subjective" DCs but leave everything else intact; and plenty of 4e players run 4e using "objective" DCs (eg I believe [MENTION=82106]AbdulAlhazred[/MENTION] is closer to this than I am, from other conversations we've had about GMing techniques).
Well, since I've got it open - rules compendium, skill DC's: "the goal is to pick a DC that is an appropriate challenge for a particular scenario or encounter."
IE: "stay within these careful guidelines because the game kind of breaks if you don't."
or: "Don't do anything too weird, that would be inappropriate."
The two paraphrases are yours. They're not what the book says, nor does it imply it. But I am getting a better sense of why you were puzzled a few years ago when I posted about the sorts of encounter sequences my group can get through without a long rest! In our last session they defeated, at level 29, a level 38 encounter (and that is a a game without Expertise feats, with MM3 damage, and with defences and hit points read out of the book). For reasons I don't understand you seem to think this is contrary to the rules and spirit of 4e.
As for the RC advice itself: where does the 5e DMG or PDF advise GMs to pick a DC that is
inappropriate ?
