1d20 — one twenty-sided die 2d6+3 — two d6, sum, plus 3 modifier 3d8-1 — three d8, sum, minus 1 4d6kh3 — four d6, k eep h ighest 3 (classic D&D 5e ability scores) 2d20kl1 — two d20, keep lowest 1 (disadvantage) 2d20kh1 — two d20, keep highest 1 (advantage) 1d100 or 1d% — percentile die d20 — N defaults to 1 if omitted

Playing online or remote, with physical dice out of reach or unavailable Streaming or recording a session and need consistent, visible rolls on camera Settling quick disputes without leaving the table ("let's roll for it"—use 1d2 ) Prototyping game mechanics or probability distributions without building a bespoke tool Running a one-shot or convention game without carrying physical dice Testing character creation rules (ability scores, hit dice, equipment)

Enter a roll expression in standard notation (e.g. 4d6kh3+2 ) and press Enter or click Roll The tool parses the expression: dice count, sides, modifiers, and keep rules Each die is rolled using crypto.getRandomValues() to generate unpredictable outcomes The results are displayed individually—you see every die result plus the final total Critical hits (natural 20) and misses (natural 1) on d20 rolls are highlighted in colour for easy scanning

Browser tab is the trust boundary. Rolls happen client-side in JavaScript. Anyone with developer tools open could inspect or alter the result. For competitive play with untrusted players, use a server-arbitrated roller. Crypto RNG is unpredictable, not "more random". A quality pseudo-RNG and cryptographic RNG produce statistically indistinguishable distributions for dice rolls. The cryptographic advantage is that past results cannot predict future ones—essential if secrecy matters. Modifiers apply once, after keeping. In 4d6kh3+2 , you roll 4d6, keep the highest 3, then add 2 total—not 2 per die. Limited notation scope. This tool supports the simple "roll, keep, and modify" subset used in ~95% of common rolls. It does not support exploding dice ( ! ), reroll rules ( r ), or success-counting ( >=7 ). If you need those, roll manually or use a more specialised tool. Crits flagged for d20 only. A natural 20 highlights green and a natural 1 highlights red, but other dice sizes receive no special colouring. Maximum 1000 dice per roll. A reasonable upper bound to preserve page responsiveness and prevent accidental spam.

Dice Roller

Roll dice with standard D&D notation — 2d6+3, 1d20, 4d6 keep highest 3. Crypto-secure RNG.

Dice notation

Examples: 1d20 · 2d6+3 · 4d6kh3 (drop lowest) · 3d8-1 · d100 · 2d20kl1 (disadvantage)

Result

Press Roll.

Roll history

(empty)

What is this for?

Tabletop role-playing games (Dungeons & Dragons, Pathfinder, the OSR, countless others) rely on dice rolls governed by compact notation: NdS means "roll N dice with S sides each". 2d6+3 means "roll two six-sided dice, sum them, and add 3". This tool parses that notation and executes the roll using the browser's cryptographic RNG, which is unpredictable and unbiased—vastly superior to Math.random() for any roll that matters.

Notation supported

1d20 — one twenty-sided die
2d6+3 — two d6, sum, plus 3 modifier
3d8-1 — three d8, sum, minus 1
4d6kh3 — four d6, keep highest 3 (classic D&D 5e ability scores)
2d20kl1 — two d20, keep lowest 1 (disadvantage)
2d20kh1 — two d20, keep highest 1 (advantage)
1d100 or 1d% — percentile die
d20 — N defaults to 1 if omitted

When to use it

Playing online or remote, with physical dice out of reach or unavailable
Streaming or recording a session and need consistent, visible rolls on camera
Settling quick disputes without leaving the table ("let's roll for it"—use 1d2)
Prototyping game mechanics or probability distributions without building a bespoke tool
Running a one-shot or convention game without carrying physical dice
Testing character creation rules (ability scores, hit dice, equipment)

How it works

Enter a roll expression in standard notation (e.g. 4d6kh3+2) and press Enter or click Roll
The tool parses the expression: dice count, sides, modifiers, and keep rules
Each die is rolled using crypto.getRandomValues() to generate unpredictable outcomes
The results are displayed individually—you see every die result plus the final total
Critical hits (natural 20) and misses (natural 1) on d20 rolls are highlighted in colour for easy scanning

Common gotchas

Browser tab is the trust boundary. Rolls happen client-side in JavaScript. Anyone with developer tools open could inspect or alter the result. For competitive play with untrusted players, use a server-arbitrated roller.
Crypto RNG is unpredictable, not "more random". A quality pseudo-RNG and cryptographic RNG produce statistically indistinguishable distributions for dice rolls. The cryptographic advantage is that past results cannot predict future ones—essential if secrecy matters.
Modifiers apply once, after keeping. In 4d6kh3+2, you roll 4d6, keep the highest 3, then add 2 total—not 2 per die.
Limited notation scope. This tool supports the simple "roll, keep, and modify" subset used in ~95% of common rolls. It does not support exploding dice (!), reroll rules (r), or success-counting (>=7). If you need those, roll manually or use a more specialised tool.
Crits flagged for d20 only. A natural 20 highlights green and a natural 1 highlights red, but other dice sizes receive no special colouring.
Maximum 1000 dice per roll. A reasonable upper bound to preserve page responsiveness and prevent accidental spam.