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Dice Roller

Die:

2d6+3

Expected average

Possible range

Dice math
average of NdS = N × (S+1)⁄2 + modifier · range = N+mod to N·S+mod

From Monopoly to D&D to deciding who does the dishes, dice are the oldest fairness machine — and this one can't be loaded. Pick a die, set the count and modifier, and roll in standard NdS±M notation with each individual die shown.

The notation, decoded

2d6+3 = two six-siders plus three. The seven-die tabletop set (d4 through d100) covers every mainstream system; the d20 carries D&D's checks while damage lives on the smaller dice. The notation line updates live as you adjust, so you always know what you're about to roll.

Expected value: know your odds before rolling

A die averages (sides+1)/2 — the d6's famous 3.5, the d20's 10.5. Multiple dice add averages: 2d6+3 expects 10, ranging 5–15. More dice also bell-curve the totals (36 ways to roll two dice, six of them totaling 7), which is why 2d6 damage feels more consistent than 1d12 despite similar averages — the central limit theorem, in miniature, at your game table.

Fairness you can't get from plastic

Physical dice are slightly biased by molding and wear; casino dice are machined to tolerances for a reason. These rolls use the browser's cryptographic randomness with rejection sampling — every face exactly 1/S likely, every roll independent. Natural 20s get their moment of glory anyway.

Related randomness

Need numbers instead of dice — raffle picks, random ranges, no-repeat draws? The random number generator shares the same crypto engine. The underlying "how likely is that total?" math unfolds in the probability calculator's two-dice mode.

Crypto-fair rolls, generated locally — works offline at the table.

Frequently Asked Questions

What does 2d6+3 mean? +

Roll two six-sided dice and add 3 to the total. The pattern is [count]d[sides][±modifier] — D&D notation, readable by every tabletop player.

What dice does D&D use? +

The classic seven-die set: d4, d6, d8, d10, d12, d20 and percentile d100. The d20 drives most checks and attacks; damage rolls use the others.

What is the average roll of a die? +

(sides + 1) ÷ 2. A d6 averages 3.5, a d20 averages 10.5. For multiple dice, multiply: 2d6 averages 7 — also its most likely total.

Are these rolls fair? +

Yes — each face has exactly equal probability via crypto.getRandomValues with rejection sampling. No streak, hot table or blowing on the screen changes the odds.

Why do two dice make 7 the most common total? +

More combinations produce it: six of the 36 ordered pairs sum to 7, versus one each for 2 and 12. More dice make totals even more bell-shaped — the central limit theorem in miniature.

What is rolling with advantage? +

A D&D 5e rule: roll two d20s and keep the higher (advantage) or lower (disadvantage). It shifts the average from 10.5 to about 13.8 or 7.2 respectively.

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