When the outcome of an action is uncertain, the game uses a d20 roll to determine success or failure. These rolls are called D20 Tests, and they come in three kinds: ability checks, saving throws, and attack rolls. They follow these steps: 4: Roll 1d20. You always want to roll high. If the roll has Advantage or Disadvantage (described later in “Playing the Game”), you roll two d20s, but you use the number from only one of them— the higher one if you have Advantage or the lower one if you have Disadvantage. 5: Add Modifiers. Add these modifiers to the number rolled on the d20: • The Relevant Ability Modifier. “Playing the Game” and “Rules Glossary” explain which ability modifiers to use for various D20 Tests. • Your Proficiency Bonus If Relevant. Each creature has a Proficiency Bonus, a number added when making a D20 Test that uses something, such as a skill, in which the creature has proficiency. See “Proficiency” later in “Playing the Game.” • Circumstantial Bonuses and Penalties. A class feature, a spell, or another rule might give a bonus or penalty to the die roll. 6: Compare the Total to a Target Number. If the total of the d20 and its modifiers equals or exceeds the target number, the D20 Test succeeds. Otherwise, it fails. The Game Master determines target numbers and tells players whether their rolls are successful. The target number for an ability check or a saving throw is called a Difficulty Class (DC). The target number for an attack roll is called an Armor Class (AC), which appears on a character sheet or in a stat block (see “Rules Glossary”). Ability Checks An ability check represents a creature using talent and training to try to overcome a challenge, such as forcing open a stuck door, picking a lock, entertaining a crowd, or deciphering a cipher. The GM and the rules often call for an ability check when a creature attempts something other than an attack that has a chance of meaningful failure. When the outcome is uncertain and narratively interesting, the dice determine the result. Ability Modifier An ability check is named for the ability modifier it uses: a Strength check, an Intelligence check, and so on. Different ability checks are called for in different situations, depending on which ability is most relevant. See the Ability Check Examples table for examples of each check’s use. Ability Check Examples AbilityMake a Check To ... StrengthLift, push, pull, or break something DexterityMove nimbly, quickly, or quietly ConstitutionPush your body beyond normal limits IntelligenceReason or remember WisdomNotice things in the environment or in creatures’ behavior CharismaInfluence, entertain, or deceive Proficiency Bonus Add your Proficiency Bonus to an ability check when the GM determines that a skill or tool proficiency is relevant to the check and you have that proficiency. For example, if a rule refers to a Strength (Acrobatics or Athletics) check, you can add your Proficiency Bonus to the check if you have proficiency in the Acrobatics or Athletics skill. See “Proficiency” later in “Playing the Game” for more information about skill and tool proficiencies.