How to Use the Online Dice Roller
Dice are one of the oldest randomization tools in human history, used in games, divination, and decision-making for thousands of years. From the simple six-sided die that comes in classic board games to the polyhedral sets used in tabletop role-playing games, dice provide a tactile, satisfying way to introduce randomness into a game or decision. This online dice roller brings that same fairness and unpredictability to the browser, supporting every standard die type and the dice notation used in modern role-playing games.
Standard Die Types
The roller supports the seven dice that make up a standard polyhedral set: D4, D6, D8, D10, D12, D20, and D100. The number after the D is the number of faces on the die — a D6 is the familiar six-sided cube with one through six pips, while a D20 is the twenty-sided die famous from D&D. The D100 is special: traditionally rolled as two ten-sided dice (one for the tens digit, one for the units), it produces a number from 1 to 100 and is used for percentile checks. Pick any die from the dropdown, set how many you want to roll, optionally add a flat modifier, and click Roll.
Modifiers and Multiple Dice
In tabletop RPGs you often need to roll multiple dice and add a fixed bonus or penalty — for example a Fireball spell might do 8D6 damage, or a strength check might be 1D20+5. Set the count field to the number of dice and the modifier field to the bonus. The roller shows each individual die result, the running sum of those dice, and the final total after the modifier is applied. This makes it easy to verify the math at a glance and lets you see if a damage roll was bad luck or just average.
DnD Quick Rolls
The preset buttons handle common D&D rolls so you do not have to set the type, count, and modifier each time. Attack rolls a single D20 — add proficiency in your head if needed. Damage rolls 2D6+3, a typical longsword damage profile. Ability rolls four D6 and drops the lowest, the standard method for generating ability scores during character creation. Advantage rolls two D20 and shows the higher result, while Disadvantage shows the lower — the 5e mechanic for situations that help or hinder a check.
Why Crypto-Random Dice Matter
Most simple dice rollers online use Math.random(), which is a pseudo-random function that is fine for casual use but technically biased and predictable. This roller uses crypto.getRandomValues(), the same cryptographically secure random source used to generate encryption keys. Each die face has exactly the right probability — a D6 returns each face one sixth of the time, a D20 returns each face one twentieth of the time. Over many rolls the distribution should be perfectly uniform, with no hidden bias that favors particular results.
Roll History
Every roll is recorded in the history panel below the dice, showing the full notation, individual results, and final total. This is useful for game masters who need to demonstrate that a roll happened, for players who want to look back and see whether a streak of bad luck was real or imagined, and for anyone tracking statistics over a play session. The history is in-memory only — refreshing the page clears it.
Frequently Asked Questions
Are the dice really fair?
Yes. The roller uses cryptographically secure randomness with rejection sampling to eliminate the small bias that occurs when a random integer is naively reduced modulo the die size. Each face has exactly equal probability.
Can I roll more than 10 dice at once?
The interface caps count at 10 to keep the display readable, but for huge dice pools you can simply click Roll multiple times and add the totals together. For very large pools an averaged result will quickly approach the expected mean.
What does "drop lowest" mean for ability scores?
The standard method to generate D&D ability scores is to roll four D6, look at the four results, and discard the lowest one — then sum the remaining three. This shifts the average ability score upward, producing more capable characters than a straight 3D6 roll would.
This dice roller is completely free, runs in your browser, and stores no data anywhere. Use it for tabletop games, classroom probability lessons, or any time you need a fair die.
Try also: Coin Flip · Spin the Wheel · Probability Calculator