D&D (2024) Auto-succeed/fail on ability checks

[Reynard]

That’s some clear wording there, they should have put that in the play test document.

The playtest document specifically said refer to the 2014 rules unless note within.

 

[Maxperson]

Again, no, this hasn't changed. The DM only calls for the roll if the PC has a chance of succeeding. If the DC for the ability check is 25 and the PC only has a +1 bonus, the DM then says that the PC automatically fails without even making the ability check. So they don't "succeed on a 20 or 21", they still need to be possible of getting a 25 total in order to succeed, they just don't get to roll unless they have a chance of getting that number.

The change in rules does not make succeeding on an ability check any easier. If a natural 20 + the PC's bonus to the check wouldn't succeed before, it still doesn't now (because the DM doesn't ask for the player to roll in that circumstance).

The change is to the last thing you said. It should be, (because the DM doesn't have to ask for the player to roll in that circumstance). With the new rule the DM is able to decide that if the PC is capable of getting within 3 of making the DC, that he might get lucky and succeed on a natural 20.

 

[Maxperson]

"Only call for a roll if there is a meaningful consequence for failure. [Note: nothing about success here.] When deciding whether to use a roll, ask yourself two questions:

• Is a task so easy and free of conflict that there should be no chance of failure?
• Is a task so inappropriate or impossible—such as hitting the moon with an arrow—that it can't work?

If the answer to both of these questions is no, some kind of roll is appropriate." (DMG 237; emphasis added)

There's a lot riding on that one, slim PHB passage for those who think DMs are never supposed to call an ability check if the PC's mods make it impossible to succeed on a nat 20. And this interpretation directly contradicts the DMG guidelines.

The bolded part is in error. It's impossible, because we think it's impossible for that PC, not because of the modifiers. This is backed up by RAW. The DMG rules you quoted don't change that. If it's impossible, there is no roll by the DMG rules. The DMG doesn't decide whether the answer to both of those questions is yes or no. The DM does. Even if a DM does decide that it's impossible due to the modifiers being too low.

 

[Maxperson]

Why would you gate a roll? What sense does that make. If there is no chance of success, there's no DC and you don't waste your players' time suggesting there is.

I don't understand. Why would I be wasting my players' time by giving those who are proficient a roll, but no roll to those who are not proficient?

 

[Sorcerers Apprentice]

I like this change, but it does require some work from the DM in adjucating which tasks are impossible and which are merely hard.
No matter how intelligent or dexterous you are, you're not going to successfully perform complex surgery unless you're trained in medicine.

But IMHO this is something the DM should already be doing in 5e. The d20 roll is too swingy to rely on it to separate experts from amateurs.

 

[Lanefan]

Yes. Every time I ask them to roll, I ask if they're proficient and what their bonus is. End of story. It's not hard, it's not much more work than not doing that (and it's well worth the effort, in my experience). So nothing else you say matters.

If their stats make it impossible, they can't do it, and therefore can't even roll. Period. The end.

The question then becomes whether that non-roll means you let them try and fail in the fiction, with whatever consequences failure might entail, or whether you tell them up front they don't have a chance and thus never expose them to the consequences of failing.

Consider the difference between the following exchanges. The PC is trying to pick a lock, the DM knows a) the lock is trapped and b) that the DC to pick it is beyond that PC's capability even at the best of times.

Player: "I try to pick the lock." <picks up a d20>
DM: "OK, you try, but soon find it's beyond your capability. You do get to roll that d20 though; but it'll be a saving throw against the poison from the trap you just set off." (the DM here assumes the PC went through the motions of trying, and applied the consequences of failure)

Player: "I try to pick the lock." <picks up a d20>
DM: "Don't bother, you have no chance of opening it." (the DM here assumes the attempt was for some reason aborted before occurring)

 

[Levistus's_Leviathan]

The question then becomes whether that non-roll means you let them try and fail in the fiction, with whatever consequences failure might entail, or whether you tell them up front they don't have a chance and thus never expose them to the consequences of failing.

Consider the difference between the following exchanges. The PC is trying to pick a lock, the DM knows a) the lock is trapped and b) that the DC to pick it is beyond that PC's capability even at the best of times.

Player: "I try to pick the lock." <picks up a d20>
DM: "OK, you try, but soon find it's beyond your capability. You do get to roll that d20 though; but it'll be a saving throw against the poison from the trap you just set off." (the DM here assumes the PC went through the motions of trying, and applied the consequences of failure)

Player: "I try to pick the lock." <picks up a d20>
DM: "Don't bother, you have no chance of opening it." (the DM here assumes the attempt was for some reason aborted before occurring)

Player: "I try to pick the lock" (their character doesn't have the required ability to so, but can at least try)
DM: "Your character quickly discovers that picking the lock is so beyond their ability that you don't even get to roll the d20. The door's traps then trigger."

The character in-world can attempt the action, but that doesn't mean the player gets to roll for it. The character can try to shoot the moon with their longbow or seduce the Mind Flayer all they want, but I'm not going to have them roll the d20 when they try to and their character will still face the consequences of their actions (losing an arrow, provoking the Mind Flayer, etc).

 

[UngainlyTitan]

The question then becomes whether that non-roll means you let them try and fail in the fiction, with whatever consequences failure might entail, or whether you tell them up front they don't have a chance and thus never expose them to the consequences of failing.

Like many things, it depends.

Consider the difference between the following exchanges. The PC is trying to pick a lock, the DM knows a) the lock is trapped and b) that the DC to pick it is beyond that PC's capability even at the best of times.

Player: "I try to pick the lock." <picks up a d20>
DM: "OK, you try, but soon find it's beyond your capability. You do get to roll that d20 though; but it'll be a saving throw against the poison from the trap you just set off." (the DM here assumes the PC went through the motions of trying, and applied the consequences of failure)

Here I would let them roll. They might not have any chance of of opening it but they do have a chance of setting off the trap.

Player: "I try to pick the lock." <picks up a d20>
DM: "Don't bother, you have no chance of opening it." (the DM here assumes the attempt was for some reason aborted before occurring)

 

[Peter BOSCO'S]

If you, as a DM, decide that X feat is impossible in the world you designed, you just dont call for check, no matter the +Y of a players. Rolling is for when there's both a chance of failure and success. If success is not possible, whether its mathematical or in-game logical, it does not matter, its already decided: the test is a failure.

If the feat is "sing in key" it may be impossible for Player P but routine for Player L, conversely if the feat is "extract a square root in your head" the feat may be routine for Player P but impossible for Player L, because L has discalcula and P is (almost) tone deaf. Why wouldn't characters be the same way?

 

[Peter BOSCO'S]

What if "automatically fails on a 1" was only for Untrained skills and "automatically succeeeds on a 20" was only for Trained skills?