Question 1

What is a d20?

Accepted Answer

A d20 is a twenty-sided die (icosahedron) with 20 faces, used in tabletop RPGs like D&D 5e and Pathfinder. The d20 is THE die of Dungeons & Dragons. Nearly every important action in the game — attacking, saving, checking skills — comes down to a d20 roll. Rolling a natural 20 is a critical hit, while a natural 1 is a critical failure. The d20 system is the core mechanic that defines the game.

Question 2

How random is this d20 roller?

Accepted Answer

Our d20 roller uses the browser crypto API to produce uniformly distributed random numbers from 1 to 20. Each face has an equal 5.00% chance.

Question 3

When do you roll a d20 in D&D?

Accepted Answer

Common uses include: Attack rolls, Saving throws, Ability checks (skill checks).

Question 4

Can I roll multiple d20 dice at once?

Accepted Answer

Yes. On the main roller you can select up to 20 dice of the same type, apply a modifier, and roll them simultaneously. The total and individual results are shown in the roll log.

Metric	Value
Each number (1–20)	5%
Average roll	10.5
Natural 20 (critical hit)	5%
Natural 1 (critical fail)	5%
Advantage: avg	13.82
Disadvantage: avg	7.18

D20 — Twenty-Sided Die (Icosahedron)

Common Uses in D&D 5e

Probabilities & Statistics

🎲 Fun Fact

Explore Other Dice