Dice Roller

Introduction

Tabletop role-playing games depend on dice for combat, skill checks, and narrative twists. When you play online, travel without a dice bag, or need a roll that everyone trusts, a virtual dice roller fills the gap. Certoflow's Dice Roller runs entirely in your browser: no account, no server-side logging, and no network call when you press Roll. Results come from the same cryptographically secure random source modern browsers use for security tokens — not a predictable pseudo-random sequence tied to the clock.

Whether you run Dungeons & Dragons 5e, Pathfinder, indie one-shots, or house-rule board games, this tool handles standard notation like 3d6+2 and custom polyhedral setups up to 20 dice with 2–100 sides each.

What this tool does

The Dice Roller gives you three inputs and one action:

1. Number of dice — how many dice to throw at once (1–20).
2. Sides per die — faces on each die (2–100). Common RPG values include d4, d6, d8, d10, d12, and d20.
3. Modifier — a flat bonus or penalty added to the sum of individual rolls (for example, +5 from a Strength modifier or −1 from exhaustion).

After you roll, the tool shows every individual result and the total including the modifier. The button label mirrors standard notation: Roll 2d20 + 3 when you configure two twenty-sided dice with a +3 modifier.

Input	Range	Typical use
Dice count	1–20	1d20 attack, 8d6 fireball
Sides	2–100	d6 damage, d100 percentile
Modifier	Any integer	Ability scores, proficiency, situational bonuses

Nothing is stored between sessions unless your browser remembers the page. Each roll is independent.

How it works

When you click Roll, Certoflow loops once per die and requests random bytes through crypto.getRandomValues() — the Web Crypto API backed by your operating system's entropy pool. Each die result is computed as (randomValue % sides) + 1, producing a face value from 1 through the configured side count.

Individual rolls are summed, then the modifier is applied to produce the displayed total. All computation happens locally in JavaScript on your device. No roll history is transmitted to Certoflow servers because the tool does not require sign-up and does not send analytics payloads tied to your dice results.

Standard dice notation reference

Notation	Meaning	Example total range (no modifier)
1d20	One twenty-sided die	1–20
2d6	Two six-sided dice, summed	2–12
4d6	Four six-sided dice (common for ability scores)	4–24
1d100	One hundred-sided die (or d10 × 10)	1–100
3d8+4	Three eight-sided dice plus 4	7–28

Modifiers follow the same convention as D&D and most d20 systems: add the modifier to the sum of dice, not to each die individually.

Real-world examples

D&D 5e attack roll

A fighter with +7 to hit rolls 1d20+7. Set count to 1, sides to 20, modifier to 7. A natural 15 on the die displays as total 22 — your hit against target AC.

Ability score generation (4d6 drop lowest)

Roll 4d6 four times for Strength, Dexterity, Constitution, and so on. Certoflow shows all four values (for example, 4, 5, 6, 6). Mentally drop the lowest (4) and sum the rest (17). Repeat for each ability. Some groups prefer the tool for the raw rolls and apply drop-lowest manually to match table tradition.

Pathfinder damage on a crit

A greataxe deals 1d12 normally and 3d12 on a critical hit. Roll once with 1d12 for a regular hit; switch to 3 dice and 12 sides for the crit, then add Strength and other bonuses via the modifier field.

Board game night

Games like Catan use 2d6 for resource production. Set count 2, sides 6, modifier 0. The sum mirrors physical dice — 7 is most likely, 2 and 12 are rare — which helps when someone forgot dice at the table.

Teaching probability

A statistics student rolls 100d6 is impractical here (max 20 dice), but rolling 20d6 ten times and recording sums demonstrates the central limit theorem: averages cluster near 3.5 × 20 = 70 as sample size grows.

Common mistakes

Adding the modifier to each die instead of the total. In d20 systems, 2d6+3 means (die1 + die2) + 3, not (die1+3) + (die2+3). Certoflow applies the modifier once to the sum — matching official rules.

Confusing d100 with d10. A true d100 roll uses sides = 100. Some groups roll d10 twice (tens and ones). This tool rolls a single uniform value from 1–100 when configured that way.

Expecting advantage/disadvantage automation. Advantage in D&D rolls 2d20 and takes the higher. This tool does not auto-select high or low; roll 2d20 and compare the two values yourself, or roll twice.

Using biased physical dice assumptions online. Virtual dice from crypto.getRandomValues() are fair within the limits of modulo reduction on very large side counts. For standard RPG dice (2–100 sides), bias is negligible for gameplay.

Forgetting negative modifiers. The modifier field accepts negative numbers. A −2 penalty on 1d20+5 is configured as modifier −2 with a +5 from stats handled separately — combine net modifier in one field (modifier 3) or track mentally.

Use cases

Online TTRPG sessions — Discord, Roll20, or theater-of-the-mind games where players want visible, fair rolls without a dice bot.

Solo journaling games — Ironsworn, Thousand Year Old Vampire, and similar titles need frequent random prompts; a bookmarked roller speeds play.

Game masters prep — Quick damage averages, random encounter checks, or loot tables without opening a full virtual tabletop.

Classroom demos — Teachers illustrate random variables and expected value with live rolls projected on a screen.

Accessibility — Players with motor difficulties or visual impairment can roll via keyboard and screen reader friendly controls instead of handling physical polyhedrals.

Streaming and content creation — Streamers show browser-based rolls so viewers see the same interface and trust the source.

FAQ

Are the dice rolls truly random?

Yes. Certoflow uses the browser's cryptographically secure random number generator (crypto.getRandomValues), the same API used for session keys and UUIDs. Results are not derived from Math.random(), which is faster but predictable if someone knows the seed state.

Can I roll multiple dice at once?

Yes. Set the number of dice and sides (for example, 3 dice with 6 sides for 3d6) and optionally add a modifier. All dice roll in one action and display as a comma-separated list plus total.

Does Certoflow store my roll history?

No. Rolls exist only in your current browser session display. There is no account and no server-side persistence of outcomes.

What is the maximum number of dice?

You can roll up to 20 dice per action, each with 2 to 100 sides. For larger pools, roll in batches and sum manually.

How do I roll with advantage or disadvantage?

Roll 2d20 (count 2, sides 20), read both values in the output, and take the higher (advantage) or lower (disadvantage) per your game's rules. The tool does not auto-resolve advantage.

Can I use this offline?

After the page loads once, the roller works without an internet connection because all logic runs client-side.

Is this suitable for competitive or tournament play?

For casual and home games, cryptographically fair rolls are appropriate. Official organized play may require physical dice or platform-integrated rollers — check your organizer's policy.

Why might my d100 roll feel different from two d10s?

A single d100 produces each value 1–100 with equal probability. Two d10s ( percentile ) can produce 00 treated as 100 depending on table convention. Know which method your group uses before comparing results.