# What's considered a bad ability check roll? Is 10 a bad roll?

I am fairly new to the D&D 5e world. I've been playing occasionally with different GMs and often I find myself or our party in the following situation:

The party enters a new location, and the GM asks us to roll a d20 for Perception. We all roll, and the best score is 14. The GM then tells us that we do not see anything and that we can proceed.

Another situation similar to this one: A rogue in the party tries to pick a lock. He rolls a d20 and gets a 13 + 2 Dex for a total of 15. The door stays locked.

A bit frustrated, I've been looking for info on these ability checks and I came along the following table:

## Typical Difficulty Classes

Very easy 5
Easy 10
Medium 15
Hard 20
Very hard 25
Nearly impossible 30

Why is 10 considered easy and 15 considered medium? We have a 50% chance to roll 10 or over, which sounds like it's medium and a 25% chances to roll 15 or over, which sounds like it's pretty hard. It seems to me that every roll we make we have a 75% chance to fail and a 25% chance to succeed. To balance the odds back to 50% on a medium task, we should have a +5 modifier in the right ability that is checked, which seems like a lot (new player, my characters aren't higher than lvl 3), maybe it balances more the more we level up?

I am probably missing something and I need help finding out what. Or maybe it is the way it is, life is unbalanced and I should deal with it. Either way I would like to know so I don't get as frustrated at my rolls ~75% of the time.

• Welcome to RPG.SE! Take the tour if you haven't already, and check out the help center for more guidance. You should edit this question to specify the RPG system/edition you're asking about. (I'm guessing it's D&D 5e, given the D&D Beyond link, though I'm not positive since it's possible your search led you to a resource for an edition different from the one you're playing.) Also, assuming it is D&D 5e, you may still want to clarify what exactly you're asking; do you understand how DCs are used in D&D 5e? What aspect of the system/rules is confusing to you?
– V2Blast
Nov 22, 2021 at 22:47
• Thanks for your insight, it is D&D 5e indeed. As I read through the D&D Beyond page I think I do understand when DCs are used (quote: An ability check tests a character's or monster's innate talent and training in an effort to overcome a challenge [...] that has a chance of failure). What I do not understand is why the medium task is at a score of 15 instead of lower and if modifiers can overcome this inequality at some point. Nov 22, 2021 at 22:52
• This might answer your question: Is the DC table applied to characters with or without proficiency? Nov 22, 2021 at 22:56
• I would mention that whatever the answer you get here, no amount of correctness can make up for this being a frustration to you, but how to handle that frustration would be a separate question Nov 22, 2021 at 23:06
• This might be relevant - it makes an Easy task (when not under time pressure) succeed 3/4 of the time when you have a friend: It seems like every skill check should always be made with advantage due to the 'Working Together' rules. Is this accurate? Nov 22, 2021 at 23:22

## Because you have bonuses

For your Wisdom (Perception) check you probably have someone with, say 16 Wisdom (+3 bonus) and who is proficient in perception (+2 bonus at low levels). That’s +5 in total meaning that they will automatically succeed on Very Easy checks, have a 80% chance on Easy, 55% on Medium and so on.

If this character is trying to perceive someone who is hiding and who has equivalent skill in Dexterity (Stealth) then this will be (on average) a Medium task. Which makes sense. If I’m as good at hiding as you are at seeking, your chance of finding me is about 50-50.

Your issue with the Rogue is slightly different. First, this character has relatively low Dexterity for a Rogue - Dexterity should be their best score and that would normally give them a +3. Maybe they were unluckily with their rolls or made sub-optimal choices in allocating their ability scores. Notwithstanding, you can’t use Thieves' Tools unless you are proficient so the Rogue should add their +2 proficiency bonus. While anyone can use a skill, you have to have proficiency to use a tool. This would give them a 16 and be enough to open a Medium lock. However, a medium lock is what you use when the thing you are securing is it important - a bike chain has a medium lock (unless it’s a very valuable bike), your house has a Hard lock, the local shop has a Very Hard lock and the bank vault has a Nearly Impossible one. Where was this lock?

In any event, failing to open the lock is just a setback. That’s why you bring the barbarian with the axe - so they can chop through the door when you can’t pick the lock. Or the wizard, who very intelligently has a Knock spell in their spellbook. Admittedly, you’re not going to be surprising anyone on the other side because both options are ... noisy but then the Rogue should just try harder.

In any event, there are a number of spells (e.g. Guidance) and class abilities (e.g. Bardic inspiration) that can give ability checks additional bonuses as well as the ability for a lesser skilled character to Help to give Advantage.

As Is the DC table applied to characters with or without proficiency? points out, the rules are clear that:

a character with a 10 in the associated ability and no proficiency will succeed at an easy task around 50 percent of the time. A moderate task requires a higher score or proficiency for success, whereas a hard task typically requires both.

An average untrained person has a 50-50 shot at an Easy task. You guys, neophyte adventurers will have some skill and some training in some things which gives you a roughly 50-50 shot at Medium tasks. Tasks that are harder than that are, well, Hard.

Of course, if more than one person can attempt the task (which is not always the case), that greatly improves the odds. 4 people with a 50-50 shot will have at least one of them succeed 15 times out of 16.

• 4 people with a 50-50 shot will have at least one of them succeed 15 times out of 16. Which is a good reason to not allow every character to attempt something. One person helping granting advantage is often a better solution. Nov 23, 2021 at 8:13
• Thank you for your extensive answer, I understand better the key points I was missing before : Bonuses, proficiency and others members helping at a task. These are the tools I needed to make it feel more balanced. As for the door, it was to the bedroom of a key character in the adventure which was actually a noble so not so surprising that the lock was hard to pick. Although the door quickly turned to pieces once our barbarian stepped in to "help". I'll ensure that my current GM knows about all this as he is also a bit new to the mechanics. Nov 23, 2021 at 13:48
• Also keep in mind that your party is low level, and that table doesn't take level into account. If your proficiency bonus is +2 and most players have a +3 ability score bonus at best, even an "expert" with assistance may struggle with a Hard task. By the time you hit level 16, you could easily be rolling with +5 proficiency and a +5 ability score, and you have a lot more sources of advantage or other enhancements, so that even Nearly Impossible tasks are, if not simple, at least within reach. Nov 23, 2021 at 14:55

Dale M's excellent answer covers a lot of your questions. I will try to answer a few things I think were neglected, especially focusing on the issues that may not be clear to you as a new player or with an inexperienced DM.

## You've got to see something, but you also have agency

The party enters a new location, and the GM asks us to roll a d20 for Perception. We all roll, and the best score is 14. The GM then tells us that we do not see anything and that we can proceed.

Based on your description, it seems that your DM has a fundamental misunderstanding of how Perception is supposed to work, and indeed the underlying process of playing the game.

1. The DM describes the environment.
2. The players describe what they want to do.
3. The DM narrates the results of the adventurers' actions.

The party enters a new location, and the GM asks us to roll a d20 for Perception: When your party enters a new location, your DM should not immediately be asking for a roll. Instead, they should be describing the environment to you, telling you everything that you can see without a roll, everything so obvious that a roll is not needed.

In addition, they should also be telling you things you can see with your Passive Perception (emphasis mine):

Passive Perception. When you hide, there's a chance someone will notice you even if they aren't searching. To determine whether such a creature notices you, the DM compares your Dexterity (Stealth) check with that creature's passive Wisdom (Perception) score, which equals 10 + the creature's Wisdom modifier, as well as any other bonuses or penalties.

So if you enter an area with a hidden rogue, a secret door, a subtle draft, etc, your DM should also be describing these things without a roll, provided at least one of your characters has a good enough Passive Perception to spot them.

Once the DM has finished telling you everything you notice without a roll, then the players describe what they want to do. At this point, you can either tell the DM that you want to move on or that you stop to search the area or investigate some feature.

It is only when you ask to do something that requires resolution that the DM narrates the results of the adventurers' actions. Even here, a roll may not be required. Simply the act of declaring your intent of interacting with the environment may reveal something. "I want to search the room," could tell you the names of the books on the shelves, that there is a piece of paper under the divan, or that a goblin is Hiding behind the curtains, all of which might be resolved without a roll, but none of which could have been seen without your declaration of your intent to search.

It is only when you ask to do something that requires resolution and for which there is both a chance of failure and a chance of success that the DM should ask for a roll (note that this is more advice than a rule).

In this case, a roll better than your Passive Perception (anyone who rolled and got more than a 10, that is, more than the lowest possible good roll) might reveal something that you did not notice automatically (with or without effort).

## Most locks can be picked with enough time

A rogue in the party tries to pick a lock. He rolls a d20 and gets a 13 + 2 Dex for a total of 15. The door stays locked.

The rogue can simply try again for a higher roll, unless the DM rules that there was some cost to the failure (and with an initial roll of 13, that would be unusual unless the lock was also trapped).

Indeed, in many situations the rogue can simply say "I will keep trying until I pick the lock," and the DM will say how long that takes.

Under "Multiple Ability Checks"(DMG, page 237):

Sometimes a character fails an ability check and wants to try again. In some cases, a character is free to do so; the only real cost is the time it takes. With enough attempts and enough time, a character should eventually succeed at the task. To speed things up, assume that a character spending ten times the normal amount of time needed to complete a task automatically succeeds at that task. However, no amount of repeating the check allows a character to turn an impossible task into a successful one.

Thus, if a character has any chance of succeeding at a check, the DM estimates how long one check would take, multiplies that by ten, and declares the character to be successful after that amount of time. 'Any chance at succeeding at the task' is most naturally interpreted as 'if the thief had rolled a 20'. So in the case of your thief with Dex +2 and, as Dale M points out, most likely proficiency in Thieves' Tools, you can automatically be assumed to have a 24 with enough time. For a thief with slightly better Dexterity, or a party with access to the guidance cantrip, that can reach a 25, or a Very Hard lock.

Now, in your comments you note that the lock in question was on the door of a noble, so time itself may have been a cost - the thief may have been discovered by guards before the lock was picked, or may have been heard by someone within the bedroom. But when time is not an issue, automatic success without a roll is available even for low-level characters attempting Very Hard tasks.

## 10 is not a bad roll - but 9 is.

What's considered a bad ability check roll? Is 10 a bad roll?

I expect you already know that things your characters attempt that have a chance of success or failure are typically resolved with a d20 roll, with 1 representing the worst luck possible (sometimes a critical failure) and 20 the best luck possible (sometimes a critical success). In between these, 2-9 is considered poor luck and 10-19 good luck, with the break point occurring between 9 and 10. As far as I know, this is not spelled out explicitly in the rules, but it is implicit in a few places, such as in Death Saving Throws (emphases mine):

Whenever you start your turn with 0 hit points, you must make a special saving throw, called a death saving throw, to determine whether you creep closer to death or hang onto life. Unlike other saving throws, this one isn't tied to any ability score. You are in the hands of fate now, aided only by spells and features that improve your chances of succeeding on a saving throw.
Roll a d20. If the roll is 10 or higher, you succeed. Otherwise, you fail.

Another place the 9 vs. 10 dichotomy is implied is in the rogue ability, reliable talent:

By 11th level, you have refined your chosen Skills until they approach perfection. Whenever you make an ability check that lets you add your Proficiency Bonus, you can treat a d20 roll of 9 or lower as a 10.

Your talent is so reliable that you actually cannot make a 'bad roll' - defined as 9 and below. You might not roll high enough to succeed at a truly difficult task, but you are guaranteed a roll that is at least good, defined as a minimum of 10.

You may notice that if 1-9 is bad luck (and this happens 45% of the time) and 10-20 is good luck (and this happens 55% of the time), then a 'good roll' is more probable than a 'bad roll'. This is intentional - the PC's are heroes, and have the odds tilted in their favor.