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Ability Checks

Ability checks determine success when attempting tasks that have a chance of failure. Roll d20 + ability modifier + proficiency (if applicable) vs. a Difficulty Class (DC).

How Ability Checks Work

Formula: d20 + ability modifier + proficiency bonus (if proficient)

The DM sets a Difficulty Class (DC). If your total meets or exceeds the DC, you succeed.

DCDifficulty
5Very Easy
10Easy
15Medium
20Hard
25Very Hard
30Nearly Impossible

Skills and Ability Checks

Skills represent specialized training in certain types of checks:

Strength: Athletics

Dexterity: Acrobatics, Sleight of Hand, Stealth

Intelligence: Arcana, History, Investigation, Nature, Religion

Wisdom: Animal Handling, Insight, Medicine, Perception, Survival

Charisma: Deception, Intimidation, Performance, Persuasion

Proficiency: If proficient in a skill, add your proficiency bonus. Otherwise, just add the ability modifier.

Passive Checks

Formula: 10 + ability modifier + proficiency bonus (if proficient)

Passive checks represent constant awareness or competence without actively trying.

Common Uses:

  • Passive Perception: Noticing hidden creatures or traps
  • Passive Investigation: Spotting unusual details
  • Passive Insight: Sensing lies or emotions

Modifiers:

Contested Checks

When two creatures oppose each other, both roll and compare totals.

Examples:

  • Grappling: Athletics vs. Athletics or Acrobatics
  • Hiding: Stealth vs. Perception
  • Shoving: Athletics vs. Athletics or Acrobatics
  • Lying: Deception vs. Insight

Ties: The situation remains unchanged (defender wins).

Common Mistakes

Common Mistake
Rolling for trivial tasks that should auto-succeed
Common Mistake
Forgetting passive Perception exists
Common Mistake
Using the wrong ability for a skill check
Common Mistake
Calling for checks when failure isn't meaningful

DM Tips

DM Tip
Only call for checks when failure is possible and interesting
DM Tip
DC 15 is appropriate for most moderately difficult tasks
DM Tip
Let players describe how they use skills creatively
DM Tip
Use passive checks to keep the game flowing