An ability check tests a character’s or monster’s innate talent and training in an effort to overcome a challenge. The DM calls for an ability check when a character or monster attempts an action (other than an attack) that has a chance of failure
For every ability check, the DM decides which of the six abilities is relevant to the task at hand and the difficulty of the task, represented by a Difficulty Class. The more difficult a task, the higher its DC. The Typical Difficulty
Classes table shows the most common DCs.
Typical Difficulty Classes
| Task Difficulty | DC |
| Very easy | 5 |
| Easy | 10 |
| Moderate | |
| Hard | 20 |
| Very hard | 25 |
| Nearly impossible | 30 |
Ability Check Modifiers
Your chance of success on an ability check is primarily determined by your ability score in the relevant ability and your proficiency in the task at hand. For ability checks, you use your Full Ability Modifier, which is different from the ability modifier used for attack rolls and saves. Your Full Ability Modifier is equal to your ability score – 10 (so a character with a Wisdom score of 13 has a Full Ability Modifier of +3 for Wisdom ability checks).
If you are allowed to add your Proficiency Bonus to an ability check, your ability check modifier is equal to the larger of the following:
Option 1: Full Ability Modifier + Proficiency Bonus
Option 2: reduced ability modifier + 2 x Proficiency Bonus
Your reduced ability modifier is the same ability modifier used for attack rolls and saving throws (ability score – 10, divided by 2, round down). So, as an example: if you have a Strength of 15 and a +2 Proficiency Bonus in the Athletics skill, your ability score modifier for an Athletics (Strength) skill check would be +7, which is the larger of +7 (Option 1: 5 + 2 = 7) and +6 (Option 2: 2 + 2 x 2 = 6).
Making an Ability Check
To make an ability check, roll a d20 and add the relevant ability
Let it Ride
Every die roll has consequences. If you fail on a check, you cannot simply reattempt it. Typically, failing a check will have consequences that change the narrative, as determined by the DM. However, even if the challenge remains after your failure, you are bound by the original die roll. Any attempts to repeat the task will automatically obtain the same result, unless the context has materially changed.
Note: this rule is an instance of gameplay trumping realism. The corollary of this rule, however, is that the DM should not require rolls for tasks that can be repeated over and over until success. For example, if you are trying to bash open a stuck door, the DM should still allow you to open the door on a failure, but with consequences (for example, it may take longer that intended and create a lot of noise). If there are no meaningful consequences of failure, the DM should simply declare an automatic success.
Additional Rule Segments
Contests
Skills
Passive Checks
Working Together
Group Checks