How is each die result generated?

Each die uses JavaScript's Math.random() to produce a cryptographically-unpredictable integer between 1 and the number of sides, inclusive. No results are biased or pre-computed.

What does the modifier do?

The modifier is an integer added to (or subtracted from) the sum of all individual die results. Enter a positive number like 3 to add +3, or a negative number like -2 to subtract 2.

How many dice can I roll at once?

You can roll 1 to 20 dice simultaneously. All individual results are shown side by side along with the combined total.

How many rolls does the history keep?

The history panel stores your last 20 rolls for the current session. It is cleared when you refresh the page or click Clear History.

What does a critical hit or fumble look like?

When you roll the maximum value on a die it is highlighted in green (critical hit). A roll of 1 is highlighted in red (critical fumble / natural 1).

Is this tool free and private?

Yes. The roller runs entirely in your browser. No data is sent to any server, and there are no accounts or tracking.

D20 Roller

Name: D20 Roller
Availability: InStock
Author: Nham Vu

Roll any RPG die (d4 through d100) with a custom quantity and modifier — see each result and the running history log.

Choose Your Die

Quantity

Modifier

Summary

Roll any RPG die (d4 through d100) with a custom quantity and modifier — see each result and the running history log.

How it works

Select a die type by clicking one of the die buttons (d4, d6, d8, d10, d12, d20, or d100).
Enter the number of dice to roll in the Quantity field (1 to 20).
Optionally enter a modifier — a positive or negative integer added to the total.
Click Roll or press Enter to roll and see individual die results and the grand total.
Consecutive rolls are logged in the History panel at the bottom for easy reference.
Click Clear History to wipe the log and start fresh.

Use cases

Roll attack rolls, damage dice, and saving throws in D&D 5e or Pathfinder.
Quickly generate a d100 percentile roll for random-event tables.
Roll 4d6 and drop the lowest for character stat generation.
Test homebrew game mechanics without hunting for physical dice.
Run a remote tabletop session and share results with the group.
Roll initiative for an entire party in seconds.

Frequently Asked Questions

Related tools

Dice Roller Dice Probability Calculator Magic 8 Ball

Last updated: 2026-05-29 · Reviewed by Nham Vu