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

[Ibrandul]

What?

Now you have me completely confused. A 22.6% success chance (an awfully precise number) is 17 or better on a D20 rolling high.
Why make them roll at all if their stats have no bearing, just roll a D20 behind the screen and tell them if you get 17 or better.

All five PCs are rolling. Under the new rule, one PC out of five needs to roll a 20 to succeed, and everyone succeeds on a 20. There’s a 22.6% chance that at least one will do so.

And let's say that one of them has a +10 to the check— a cleric with a +5 Wis mod, plus a proficiency bonus of +5 at level 16. Everyone else's mods are lower. Under the old rule, that cleric had a 5% chance of success, and no one else had a chance (unless they boosted it with bardic inspiration, etc., if the DM permitted that). Under the new rule, the cleric has the same chance of success as everybody else. Her stats and skills do not matter.

 

[Li Shenron]

The 5.5e playtest includes just one change I really hate: a 20 automatically succeeds on an ability check, and a 1 automatically fails.

I've seen precisely one rationale for this, stated over and over, that most groups already play that way because this is already a widely misunderstood rule—not that groups are already playing this way as a house rule despite being aware of the official rule. Crawford says they are changing the game so that the rules work "the way people expect them to work."

But is the game better this way?

If it's not—if the game is better with the current rule, not the new one—then surely a better approach would be to change the way this rule is presented in the PHB so that it is easy to understand and to absorb, rather than changing the rule itself.

And I think the change is a very bad one.

Imagine a DC 25 ability check. The game defines a DC 25 task as "very hard." Right now, a character with a total +5 modifier in the skill has a 5% chance of succeeding: on a roll of a 20 only. If you have a lower modifier, you just can't perform the task—you're just not acrobatic enough, or knowledgable enough about arcana, or whatever, to succeed at this very hard task. But with the new rule, the PC who has a negative modifier—even, potentially, a big one—has the same 5% chance of success as the PC who supposedly excels in this area.

It gets even worse with a DC 30 check to perform a "nearly impossible" task. The character with a +10 has a 5% chance of success—the same as every other PC in the game.

What's the rationale for why this change makes the game a better game?

You're not wrong. This rule change is oddly one of the few that I am not personally worried about, but I can see how it can ruin other DMs' gamestyle.

I base my games off "rule zero" so I already grant rolls only sometimes and to someone. Just because I granted it to PC1, it doesn't mean PC2 and PC3 have the right to roll too. This is also how I manage to cope with the excess swingyness of the d20 in ability checks. For example I often grant some checks only to those who have proficiency.

So in effect, whether a natural 1 is an autofail and a natural 20 is an autosuccess or not, is not that important in my games. If I am granting you the roll in the first place it means I accept both success and failure as possible outcomes. If I didn't, then I'd just tell you flat-out "you succeed" or "you fail" without asking you to roll.

But I am aware that this is not how other DMs run the game. Some just feel like players are entitled to ask for a roll. Some want a game where everyone always has at least a slim chance at anything, including jumping onto the moon, and they are not going to have issues with this rule for different reasons than mine.

I am only sorry for those DM who maybe don't want to, but cave in to the players requests, and perhaps found some consolation in the possibility of claiming the DC was too high anyway. With this new rule they can't. I could just rejoice at the fact that this will teach them a lesson to use rule zero more often as I already do, but it does carry a mild scent of badwrongfun attitude to me.

 

[UngainlyTitan]

All five PCs are rolling. Under the new rule, one PC out of five needs to roll a 20 to succeed, and everyone succeeds on a 20. There’s a 22.6% chance that at least one will do so.

Why are all 5 rolling? It is not a group check. What is the narration for the barbarian to roll? What is the actual DC?

And let's say that one of them has a +10 to the check— a cleric with a +5 Wis mod, plus a proficiency bonus of +5 at level 16. Everyone else's mods are lower. Under the old rule, that cleric had a 5% chance of success, and no one else had a chance (unless they boosted it with bardic inspiration, etc., if the DM permitted that). Under the new rule, the cleric has the same chance of success as everybody else. Her stats and skills do not matter.

Ok, now I think I get it, the DC is 30 the cleric with +10 has a 5% change on a 20.
Aside from the fact that I would never run things this way, If I am allowing a roll then there is a chance of success or failure and I do not allow everyone to roll and I am willing to gate rolls behind proficiency or high stat mods.
In the circumstances outlined I would only permit the cleric to attempt the check.

I guess you will have to houserule? I do not have any useful suggestions.

 

[MarkB]

All five PCs are rolling. Under the new rule, one PC out of five needs to roll a 20 to succeed, and everyone succeeds on a 20. There’s a 22.6% chance that at least one will do so.

Only if you're letting them all roll. There are criteria other than DC that you can apply when considering who's eligible to roll, proficiency being the most obvious, but far from the only one.

And let's say that one of them has a +10 to the check— a cleric with a +5 Wis mod, plus a proficiency bonus of +5 at level 16. Everyone else's mods are lower. Under the old rule, that cleric had a 5% chance of success, and no one else had a chance (unless they boosted it with bardic inspiration, etc., if the DM permitted that). Under the new rule, the cleric has the same chance of success as everybody else. Her stats and skills do not matter.

Only at that one specific DC. You're presenting an edge case as a universal.

And that sort of edge case already occurs in the game. If the party are up against a creature with AC 25 and the Fighter's +5 to hit is the highest in the party, they all have the same chance to hit - the Fighter's stats don't matter in that one instance. Has that ever bothered you in-game?

 

[Ibrandul]

Only at that one specific DC. You're presenting an edge case as a universal.

I don't intend for it to be taken as universal. I was asked for an example of why I might set a DC at 30 for the sake of world-building; I gave the example; then I was told the new rule wouldn't make a difference in that case, when it actually more than quadruples the chance of success.

I don't think this is some sort of mic-drop moment. And this thread has taught me one thing: even though I try to DM RAW, and I know that each DM's style is unique in some way, I suspect that almost no one DMs D&D like I do regarding ability checks.

Which is neat, I guess. And maybe it gives me some further insight into why I've had so many experienced players tell me that of all the campaigns they've ever played in, mine was the only one where the world felt real. (I'm not saying this to brag; I'm saying it to convey why I DM the way I do.)

But there's no question in my mind: I will either have to change my DMing style, or refuse to adopt the new rule.

And that sort of edge case already occurs in the game. If the party are up against a creature with AC 25 and the Fighter's +5 to hit is the highest in the party, they all have the same chance to hit - the Fighter's stats don't matter in that one instance. Has that ever bothered you in-game?

On the contrary, I think the rule is good for attack rolls; good for saving throws (I think—though my thoughts aren't fully formed on this one, since I hadn't started thinking about it until the playtest document dropped on Thursday); and terrible for ability checks (which I started thinking about a long time ago).

That's partly because I have never seen any encounter with a party where only one PC has an attack modifier as high as +5 facing off against an AC 25 monster—or anything remotely comparable to that.

And since it sounds like very few of my fellow DMs have ever seen a DM call for an ability check with a DC higher than 20 or maybe 22, I do understand where they're coming from.

 

[Lanefan]

I am trying to understand what you are trying to achieve here and explaining where I am coming from.
If you have information gated behind a DC 30 and you have level 10 PCs then a character with max stat and no proficiency is +5 on the roll. Then no chance of success even with Bless, may be with Bardic Inspiration if the bard is level 10 or better.
If they have proficiency in a relevant skill it is +9, still no chance though bless and Bardic Inspiration does make it possible. Even with expertise it is still pretty low odds even with bless or bardic inspiration.

Changing to autosuccess on a 20 dies not make a noticeable difference to the odds,

In fact it makes an infinite amount of difference, at least in mathematical terms, as the odds go from outright zero to something - anything - higher than zero.

not one that will be spotted in play.

Perhaps, though I long ago learned - sometimes the hard way - not to assume corner cases will always remain in the corner.

If it is relevant to the progression of the plot, what is the point of the high DC and if it has no relevance what does it matter?

In part because while the DM knows the lore's degree of plot (ir)relevance, the players don't. From the player side, it's simply an attempt to access some obscure bit of information.

 

[Lanefan]

I think trying to make the rules of D&D model "reality" is a losing proposition.

Maybe so, but that's not going to stop me from trying.

On top of that, setting an arbitrary limit like that without examining how it interacts with all the related systems is just bad design.

Perhaps, though in this case I'm not sure whether there'd really be any serious knock-on effects.

 

[UngainlyTitan]

In fact it makes an infinite amount of difference, at least in mathematical terms, as the odds go from outright zero to something - anything - higher than zero.

Perhaps, though I long ago learned - sometimes the hard way - not to assume corner cases will always remain in the corner.

In part because while the DM knows the lore's degree of plot (ir)relevance, the players don't. From the player side, it's simply an attempt to access some obscure bit of information.

I am, and remain of the view, if something is impossible then no roll.

 

[beancounter]

The "new" nat 20 rule essentially gives everyone an equal chance to succeed regardless of their skills or proficiencies.

While it will certainly promote the warm and fuzzies, it's just unrealistic to assume everyone has an equal chance of success.

It's a poor attempt to level the playing field, where there shouldn't be a level playing field.

 

[Lanefan]

I am, and remain of the view, if something is impossible then no roll.

Agreed.

What is glaringly missing, however, is any real granularity between 5% possible and 0% possible; where instead there ideally would be a long trailing end of a bell curve. Hence my idea upthread of where a 20 still doesn't beat the DC even after modifiers, a secondary die is rolled to maybe give it that little extra push. The size of that secondary die is 1+ the difference between the modified roll total and the DC*, and only a max roll on that die gives success.

* - thus if the modified total misses the DC by 1 the confirm die is a d2; if the modified total misses by 5 it's a d6, and so forth.