Is the random roll cryptographically secure?

No. It uses Math.random() for simplicity. Use specialist tools for gambling or security-critical randomness.

Can I roll exploding dice?

Not yet. Enter multiple simulations or build a house rule variant; future updates may include advanced options.

Can I see the probability of rolling a specific number?

This tool only shows a single roll plus min/max/average. For full probability distributions (for example, the chance of rolling 10 or higher on 3d6), you’ll need a dedicated probability calculator or dice math reference.

Does this support advantage/disadvantage style mechanics?

Not directly. You can approximate by rolling twice and manually taking the higher or lower result, but there is no built‑in advantage/disadvantage option.

everyday calculator

Dice Roll Simulator

Simulate table-top dice rolls and see the possible range plus average result.

Results

Simulated roll: 3.00
Minimum total: 2.00
Maximum total: 12.00
Average total: 7.00

Overview

Dice are the heartbeat of tabletop games, from simple board games to complex RPGs. But sometimes you don’t have a full set of physical dice handy, or you want a quick way to visualize typical roll ranges and averages for a particular dice expression.

This dice roll simulator lets you roll any number of fair dice with any number of sides (d4, d6, d8, d10, d12, d20, or custom) and apply a modifier, just like “2d6 + 1” or “1d20 − 2” on a character sheet. You see a single simulated result, plus the minimum, maximum, and average possible totals so you can understand how swingy the roll is.

It’s ideal for quick rolls, teaching probability basics, or testing whether a homebrew rule feels balanced before you bring it to the table.

How to use this calculator

Enter how many dice you want to roll (for example, 2 for “2d6” or 3 for “3d8”).
Enter the number of sides each die has—for standard dice, this might be 4, 6, 8, 10, 12, or 20; you can also use custom values.
Enter a modifier (positive or negative) if you want to add bonuses or penalties, such as ability modifiers in RPGs.
Run the calculator to generate a single random roll result and view the min, max, and average totals for that dice configuration.
Rerun as needed for additional random samples, or adjust the inputs to explore how different dice and modifiers affect the distribution.

Inputs explained

Number of dice: How many dice to roll at once—for example, 2 for 2d6 damage or 4 for rolling multiple d6s and summing the result.
Sides per die: The number of faces on each die. Common values are 4, 6, 8, 10, 12, and 20, but you can enter custom sizes to simulate unusual or virtual dice.
Modifier: A bonus or penalty applied to the total roll after all dice are summed. Enter positive numbers for bonuses (e.g., +3) and negative numbers for penalties (e.g., −2).

Outputs explained

Simulated roll: The result of a single simulated roll of the specified dice plus the modifier. This is the number you might use for a check, save, or damage roll in a game.
Minimum total: The lowest possible total for your dice configuration, including the modifier. It occurs when every die rolls its minimum value (1).
Maximum total: The highest possible total, including the modifier. It occurs when every die rolls its maximum face value (equal to the number of sides).
Average total: The expected total over many rolls for this dice configuration. It helps you understand the typical outcome and calibrate the power level of homebrew rules.

How it works

You specify the number of dice, the number of sides on each die (for example, 6 for d6 or 20 for d20), and an optional modifier to apply to the total.

For the simulated roll, the calculator generates a random integer from 1 to the number of sides for each die, sums all those rolls, and then adds the modifier.

The minimum total is computed as (Number of dice × 1) + Modifier, since each die can roll as low as 1.

The maximum total is computed as (Number of dice × Sides) + Modifier, since each die can roll up to its maximum face value.

The average (expected value) is Number of dice × (Sides + 1) ÷ 2 + Modifier, because a single fair die has an average of (Sides + 1) ÷ 2.

Every time you click or rerun the calculator, it generates a new random sample while keeping the same min, max, and average for context.

Formula

Let D = Number of dice
Let S = Sides per die
Let M = Modifier

Minimum total = D × 1 + M
Maximum total = D × S + M
Average total = D × (S + 1) ÷ 2 + M

Simulated roll = (Sum of D random integers from 1 to S) + M

When to use it

Rolling checks, attacks, or damage in tabletop RPGs when physical dice aren’t available or convenient.
Demonstrating randomness and averages in a classroom or workshop using familiar dice examples.
Testing custom dice expressions or house rules (for example, changing from 1d12 to 2d6) to compare average outcomes and variability.
Quickly checking the range and average of a complex dice expression to see whether it fits the power level you expect.
Creating simple probability illustrations for blog posts, streams, or session prep.

Tips & cautions

Use the average total to compare different dice choices when designing homebrew spells, weapons, or abilities.
If you want more stable results with less swing, try rolling more dice with fewer sides (for example, 3d6) instead of fewer dice with more sides (like 1d18).
Modifiers can be used to represent ability scores, proficiency bonuses, or situational modifiers—enter them exactly as they appear on your character sheet.
For very large numbers of dice, the distribution of outcomes will concentrate more tightly around the average; this is useful when you want less randomness.
Remember that this simulator is for casual use; if you need cryptographically secure or auditable randomness for tournaments or regulated gaming, use approved tools.
Simulates a single roll at a time and does not display the full probability distribution or percentile odds for specific totals.
Uses Math.random() under the hood and is not cryptographically secure or suitable for regulated gambling or high‑stakes randomness.
Assumes fair dice with equally likely faces; it does not model loaded or biased dice.
Does not support advanced mechanics like exploding dice, advantage/disadvantage, rerolls, or keep/drop highest—those require more specialized tools.

Worked examples

2d6 + 1

Min = 3
Max = 13
Average ≈ 8
Random roll varies each click.

1d20 skill check

Min = 1
Max = 20
Average = 10.5 (before modifiers).

3d8 − 2 homebrew damage

D = 3, S = 8, M = −2.
Min = (3 × 1) − 2 = 1.
Max = (3 × 8) − 2 = 22.
Average = 3 × (8 + 1) ÷ 2 − 2 = 3 × 4.5 − 2 = 13.5 − 2 = 11.5.
You can use these numbers to compare this attack to a standard damage option.

Deep dive

This dice roll simulator rolls any number of dice with custom sides and modifiers, showing a random result plus minimum, maximum, and average totals.

Use it for tabletop RPGs, board games, or classroom probability demos when you need a quick virtual dice roller and basic stats for your dice expression.

Because it displays the minimum, maximum, and average results for your chosen dice setup, you can quickly compare different damage expressions or check how swingy a homebrew rule might feel at the table before you introduce it to your group.

You can also use the dice roll simulator as a teaching aid when introducing probability to students or new players: adjust the number of dice and sides, ask them to guess how the average will change, and then use the calculator’s outputs to confirm their intuition and spark discussion about randomness and expected value.

FAQs

Is the random roll cryptographically secure?: No. It uses Math.random() for simplicity. Use specialist tools for gambling or security-critical randomness.
Can I roll exploding dice?: Not yet. Enter multiple simulations or build a house rule variant; future updates may include advanced options.
Can I see the probability of rolling a specific number?: This tool only shows a single roll plus min/max/average. For full probability distributions (for example, the chance of rolling 10 or higher on 3d6), you’ll need a dedicated probability calculator or dice math reference.
Does this support advantage/disadvantage style mechanics?: Not directly. You can approximate by rolling twice and manually taking the higher or lower result, but there is no built‑in advantage/disadvantage option.

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Results reset each time you re-run the calculator. For official tournaments use approved dice-rolling methods.