An ability check tests a character's or monster's innate talent and training in an effort to overcome a challenge. The GM calls for an ability check when a character or monster attempts an action (other than an attack) that has a chance of failure. When the outcome is uncertain, the dice determine the results.
For every ability check, the GM decides which of the six abilities is relevant to the task at hand and the difficulty of the task, represented by a Difficulty Class (DC). The more difficult a task, the higher its DC. The Typical Difficulty Classes table shows the most common DCs.
Typical Difficulty Classes:
• Very Easy: DC 5
• Easy: DC 10
• Medium: DC 15
• Hard: DC 20
• Very Hard: DC 25
• Nearly Impossible: DC 30
To make an ability check, roll a d20 and add the relevant ability modifier. As with other d20 rolls, apply bonuses and penalties, and compare the total to the DC. If the total equals or exceeds the DC, the ability check is a success.
Characters have a proficiency bonus determined by level. Monsters also have this bonus, which is incorporated in their stat blocks. The bonus is used in the rules on ability checks, saving throws, and attack rolls.
Your proficiency bonus can't be added to a single die roll or other number more than once. For example, if two different rules say you can add your proficiency bonus to a Wisdom saving throw, you nevertheless add the bonus only once when you make the save.
Occasionally, your proficiency bonus might be multiplied or divided (doubled or halved, for example) before you apply it. For example, the rogue's Expertise feature doubles the proficiency bonus for certain ability checks. If a circumstance suggests that your proficiency bonus applies more than once to the same roll, you still add it only once and multiply or divide it only once.
Sometimes a special ability or spell tells you that you have advantage or disadvantage on an ability check, a saving throw, or an attack roll. When that happens, you roll a second d20 when you make the roll. Use the higher of the two rolls if you have advantage, and use the lower roll if you have disadvantage.
If multiple situations affect a roll and each one grants advantage or imposes disadvantage on it, you don't roll more than one additional d20. If two favorable situations grant advantage, for example, you still roll only one additional d20.
If circumstances cause a roll to have both advantage and disadvantage, you are considered to have neither of them, and you roll one d20. This is true even if multiple circumstances impose disadvantage and only one grants advantage or vice versa. In such a situation, you have neither advantage nor disadvantage.
A saving throw—also called a save—represents an attempt to resist a spell, a trap, a poison, a disease, or a similar threat. You don't normally decide to make a saving throw; you are forced to make one because your character or monster is at risk of harm.
To make a saving throw, roll a d20 and add the appropriate ability modifier. For example, you use your Dexterity modifier for a Dexterity saving throw.
A saving throw can be modified by a situational bonus or penalty and can be affected by advantage and disadvantage, as determined by the GM.
The Difficulty Class for a saving throw is determined by the effect that causes it. For example, the DC for a saving throw allowed by a spell is determined by the caster's spellcasting ability and proficiency bonus.
The result of a successful or failed saving throw is also detailed in the effect that allows the save. Usually, a successful save means that a creature suffers no harm, or reduced harm, from an effect.
Strength measures bodily power, athletic training, and the extent to which you can exert raw physical force.
Athletics: Your Strength (Athletics) check covers difficult situations you encounter while climbing, jumping, or swimming.
Lifting and Carrying: Your carrying capacity is your Strength score multiplied by 15. You can push, drag, or lift a weight in pounds up to twice your carrying capacity (or 30 times your Strength score). While pushing or dragging weight in excess of your carrying capacity, your speed drops to 5 feet.
Dexterity measures agility, reflexes, and balance.
Acrobatics: Your Dexterity (Acrobatics) check covers your attempt to stay on your feet in a tricky situation, such as when you're trying to run across a sheet of ice, balance on a tightrope, or stay upright on a rocking ship's deck.
Sleight of Hand: Whenever you attempt an act of legerdemain or manual trickery, such as planting something on someone else or concealing an object on your person, make a Dexterity (Sleight of Hand) check.
Stealth: Make a Dexterity (Stealth) check when you attempt to conceal yourself from enemies, slink past guards, slip away without being noticed, or sneak up on someone without being seen or heard.
Constitution measures health, stamina, and vital force. Constitution checks are uncommon, and no skills apply to Constitution checks, because the endurance this ability represents is largely passive rather than involving a specific effort on the part of a character or monster.
Intelligence measures mental acuity, accuracy of recall, and the ability to reason.
Arcana: Measures your ability to recall lore about spells, magic items, eldritch symbols, magical traditions, the planes of existence, and the inhabitants of those planes.
History: Measures your ability to recall lore about historical events, legendary people, ancient kingdoms, past disputes, recent wars, and lost civilizations.
Investigation: When you look around for clues and make deductions based on those clues, you make an Intelligence (Investigation) check.
Nature: Measures your ability to recall lore about terrain, plants and animals, the weather, and natural cycles.
Religion: Measures your ability to recall lore about deities, rites and prayers, religious hierarchies, holy symbols, and the practices of secret cults.
Wisdom reflects how attuned you are to the world around you and represents perceptiveness and intuition.
Animal Handling: When there is any question whether you can calm down a domesticated animal, keep a mount from getting spooked, or intuit an animal's intentions, the GM might call for a Wisdom (Animal Handling) check.
Insight: Your Wisdom (Insight) check decides whether you can determine the true intentions of a creature, such as when searching out a lie or predicting someone's next move.
Medicine: A Wisdom (Medicine) check lets you try to stabilize a dying companion or diagnose an illness.
Perception: Your Wisdom (Perception) check lets you spot, hear, or otherwise detect the presence of something. It measures your general awareness of your surroundings and the keenness of your senses.
Survival: The GM might ask you to make a Wisdom (Survival) check to follow tracks, hunt wild game, guide your group through frozen wastelands, identify signs that owlbears live nearby, predict the weather, or avoid quicksand and other natural hazards.
Charisma measures your ability to interact effectively with others. It includes such factors as confidence and eloquence, and it can represent a charming or commanding personality.
Deception: Your Charisma (Deception) check determines whether you can convincingly hide the truth, either verbally or through your actions.
Intimidation: When you attempt to influence someone through overt threats, hostile actions, and physical violence, the GM might ask you to make a Charisma (Intimidation) check.
Performance: Your Charisma (Performance) check determines how well you can delight an audience with music, dance, acting, storytelling, or some other form of entertainment.
Persuasion: When you attempt to influence someone or a group of people with tact, social graces, or good nature, the GM might ask you to make a Charisma (Persuasion) check.