Difficulty Class

For a comprehensive summary of the mechanics behind all rolls and modifiers, see Die Rolls.

Difficulty Class (or DC) is a number that must be matched or exceeded to achieve success when rolling for Ability Checks or Saving Throws.

When attempting to beat - called a Saving Throw - a Difficulty Class, the die rolled is a  d20. The modifiers applied to this roll vary, depending on the circumstances and the type of check.

The Difficulty Class (DC) is determined by the source of danger.

Danger DC

In scenarios such as traps, the game chooses an appropriate Difficulty Class, depending on how serious the danger is. This includes single-use items such as elemental arrows or throwables.

Weapon Action DC

The Difficulty Class of a Weapon Action that imposes a Saving Throw is calculated similarly to Spellcasting DC - except the Spellcasting Ability Modifier is replaced with either Strength or Dexterity, whichever is higher. This is true even when the weapon uses the wielder's Spellcasting Ability Modifier, such as a Warlock's Pact Weapon. Additionally, base DC is 10. Each Weapon Action also grants its own inherent bonus DC that isn't listed anywhere, but most frequently it's +2. Certain Weapon Action also uses a Hybrid Bonus DC, which allows for a user's highest Ability Score Modifier to be used instead.

Difficulty Class = 10 + Strength or Dexterity + Inherent Weapon Action Bonus DC

Spell DC

For the Difficulty Class of a Spell that imposes a Saving Throw, the DC is determined by the creature's Spellcasting Ability Modifier, using the following formula:

Difficulty Class = 8 + Proficiency Bonus + Spellcasting Ability Modifier