Skip to main content

Dice mechanics

Percentile (d100) checks in Dungeons & Dragons 5th Edition

Roll under skill mechanics and difficulty bands.

Explanation

Percentile checks resolve by rolling d100 and succeeding at/under a target value. This mechanic is most directly associated with Call of Cthulhu-style play loops.

At the table (quick loop)
  • Build your pool from the relevant traits.
  • Roll and count successes according to the system’s thresholds.
  • Apply consequences and record changes on the sheet.
Example: Treat every roll as a decision: success advances, failure changes the situation.
Examples
Example: skill target

If a system uses percentile checks, roll d100 and succeed at/under the target value.

Example: fail forward

If the clue matters, don't block progress on failure. Trade success for time, noise, or a new complication.

Common mistakes (smallest fix)
  • Mistake: Forgetting difficulty bands. Fix: Use Regular/Hard/Extreme (or your table’s bands) to express stakes quickly.
  • Mistake: Failure stops the investigation. Fix: Fail forward: you still get something, but pay a cost.
More dice mistakes

Dungeons & Dragons 5th Edition FAQ

How does the d20 system work in D&D 5e?
What are the ability scores in D&D 5e?
How does advantage and disadvantage work?
What class should I play as a beginner?
How does spellcasting work in D&D 5e?

Keep play fast

Use quick references, then jump back into the scene.