Let's say the party sees a 20' wall and wants to get over it. The player with the weaker character describes wanting to use the rickety extension ladder that is lying on the ground while the player with the stronger character describes wanting just to climb the very smooth wall. Let's say both require checks. Yes, the one using the ladder might have a lower DC than the one climbing the smooth wall. Using the ladder was a better approach in this situation. And maybe the character climbing the smooth wall has a personality trait that says they prefer to do things the hard way (earning them inspiration). Or maybe not. What their PCs choose to do is up to them.
I think this is very low-hanging fruit for your preferred approach.
What if the situation described by the GM is
strange glowing sigils hanging suspended in the air? And then a player delcares
I want to try and ascertain whether or not the sigils are an interdimensional portal, without actually triggering them. And let's suppose that there is no prior established fiction that allows a player to answer that question just by drawing on their PC's short-to-medium-term memory.
To me it seems natural to suppose that a PC who is proficient in Arcana might have a greater chance of achieving that goal, compared to one who doesn't, because (per the Basic PDF p 61), "Your Intelligence (Arcana) check measures your ability to recall lore about spells, magic items, eldritch symbols, magical traditions, the planes of existence, and the inhabitants of those planes."
What method is the player going to describe that circumvents the need, then-and-there, for an INT (Arcana) check and makes success automatic?
I read the sigils really closely while reaching out with my mind's eye? And that's before we even get to the question of how that suggested action declaration might relate to the use of a Detect Magic spell, which presumably is the canonical way (in 5e D&D) of reaching out with one's mind's eye to try and ascertain the nature of a magical effect.
A very different example might be a player's declared action, for their PC, to build a trap similar to
this one. In that thread, the discussion over whether and how the trap would work quickly got into very technical inquiries about hydrostatic pressures, the sheering properties of gels, etc. What if neither the GM nor the player of the trap-builder have done graduate level chemical engineering? What sort of approach is a player expected to describe their PC taking?
This looks like the sort of thing covered on p 61 of the Basic PD under the heading "Other Intelligence Checks":
The DM might call for an Intelligence check when you try to accomplish tasks like the following: . . .
• Recall lore about a craft or trade
That same list includes, as one of its dot points, "Win a game of skill". I think
@HammerMan would find it objectionable, in play, for INT 8 barbarian to beat the local sage at a chess match because the player of that barbarian is a skilled chess player and so able to beat the GM who makes the moves for the sage!
It seems to me that you presume that ability scores and proficiencies define how a player must play their character or how a DM must treat a character.
I'm sure that
@HammerMan is treating this as a premise in their reasoning!
And just as your ladder example is low-hanging fruit for you, I think my chess example is low-hanging fruit for HammerMan.
The wizard can't beat the ogre in combat because the wizard's player trains in judo twice a week while the GM has never been in a fight in their life. So it would seem odd that the INT 8 barbarian can regularly beat all comers at chess because the player is highly ranked at the local chess club while the GM is a rank amateur.
Is there a case where what the player says indicates they are doing something more (maybe with extra cost) and that changes the difficulty and possible ramifications?
I sneak down the hall vs. I take off my boots and stuff a shirt in my quiver and sneak down the hall, or I intimidate the guard vs. I use what my character learned about the guards family last time and try to intimidate them by threatening the family.
One puzzle I have with this is that if a player's PC is not trained in Stealth, yet a player has their PC do this, it seems to belie sone of what is said in the Basic PDF. For instance, the rogue class description says the following (pp 26-27):
Rogues devote as much effort to mastering the use of a variety of skills as they do to perfecting their combat abilities, giving them a broad expertise that few other
characters can match. . . .
Expertise
At 1st level, choose two of your skill proficiencies, or one of your skill proficiencies and your proficiency with thieves’ tools. Your proficiency bonus is doubled for any ability check you make that uses either of the chosen proficiencies.
To me, this strongly implies that skill proficiency, including skill proficiency as enhanced by the expertise class feature, represents a character's master of various "knacks" for doing things like sneaking around, picking locks, etc. But if a player is free to draw on their own mastery of such knacks - eg by doing what you have said, and describing what their PC does to try and be sneaky - then we now have a PC who has mastered those knacks and yet does not have proficiency, expertise etc. That's weird. The game doesn't use the same thing for PCs' combat abilities, nor for their ability to pray to the gods or use their mind's eye to read the mind of another, so why does it do it for sneaking and lock-picking, in apparent contradiction of the rogue class description?
The same thought is prompted by this on p 58 of the Basic PDF:
A skill represents a specific aspect of an ability score, and an individual’s proficiency in a skill demonstrates a focus on that aspect.
For example, a Dexterity check might reflect a character’s attempt to pull off an acrobatic stunt, to palm an object, or to stay hidden. Each of these aspects of Dexterity has an associated skill: Acrobatics, Sleight of Hand, and Stealth, respectively. So a character who has proficiency in the Stealth skill is particularly good at Dexterity checks related to sneaking and hiding.
Now there's a weirdness in that passage - a Dexterity check is something that takes place at the table, not in the fiction, and so what does it mean to say that a character is particularly good at making one? - but if we ignore that and try and makes sense of the passage in spite of it, it strongly implies that skill proficiencies are a game mechanical representation of a character's focus on one aspect of their ability in virtue of which they are particularly good at that thing.
Again, it seems to belie that rules text if a PC can be particularly good at a thing - say, sneaking around - because the
player is good at the thing in question and so describes their PC doing it well.
I don't have a view on how to resolve this issue within the context of 5e - frankly, the issue is another reason I don't play 5e - but I don't think anyone can be shocked that the game produces different approaches to play that resolve the issue in different ways. Some, like
@Swarmkeeper and (I think) you favour adjudication of at least some declared actions by reference to fictional positioning, even though this means that a PC can be good at those things although that is not reflected in the ability score + skill elements of the PC's build; others, like
@HammerMan and (perhaps?)
@prabe treat the PC's mechanical build as a canonical statement of what the PC is good at, and adjudicate by reference to that rather than purely based on fictional positioning.
