Free Dice Roller & Probability Calculator

Dicelab: Best Free Dice Roller for D&D 5e

Simple rollers give you the number. Dicelab gives you the answer. The online dice roller and probability calculator for power users.

✓ D&D 5e and Pathfinder dice syntax (Advantage, Drop Lowest, Reroll)
✓ Instant probability distributions and stats
✓ Offline-first and highly performant

Open Dicelab Free → Add to Discord

                        # Attack with Advantage + Bless

                        d20 adv + 1d4 + 5

                        → 23

                        # Fireball Damage

                        8d6

                        → 28 (3+6+2+5+4+1+3+4)

                        let gwm = (d20+3) >= 17 ? 2d6+15 : 0

                        let normal = (d20+8) >= 17 ? 2d6+5 : 0

                        analyze gwm^2, normal^2

                        → GWM Mean: 18.6

                        → Normal Mean: 14.2

Data-Driven Rolling

See the Math Behind the Roll

Don't guess if "Great Weapon Master" is worth it. Know it. Dicelab instantly generates probability distributions, expected damage tables, and hit chances for any D&D 5e formula.

📊 Instant Analysis

Type analyze 8d6 to see your exact odds of rolling high damage.

⚔️ Complex Comparisons

Compare multiple builds side-by-side to optimize your character.

Dicelab Features

Complete Dice Roller Toolkit

🎲

Attack Dice Roller

Crit ranges, on-crit scaling, hit-or-miss conditionals.

📊

Probability Charts

Full PMF with mean, range, percentiles.

💾

Saved Formulas

let smite = 2d8. Save formulas and D&D Beyond aliases.

💬

Discord Dice Bot

Use /roll directly in your server.

📱

Mobile Dice Roller

PWA. Roll dice offline on your phone during game night.

📥

D&D Beyond Import

Import characters to auto-generate attack aliases.

When to Use Dicelab

Before and During Your Game

Before Play: Plan & Optimize

Use the Dicelab dice roller to theory-craft builds. Compare Great Weapon Master vs Polearm Master. Find the break-even AC. Model expected DPR with exact probability distributions.

During Play: Roll & Share

Use Dicelab as your session dice roller. Complex attack sequences in one formula. Do your ability checks easily with imported character sheet. Works on mobile and offline.

Dice Roller Syntax

Dicelab Dice Notation

The Dicelab dice roller understands every D&D mechanic. Write formulas naturally.

Core Rolls

d20 adv Advantage

d20 dis Disadvantage

4d6 dl 1 Drop Lowest 1

4d6 kh 3 Keep Highest 3

2d6 rr 1 Reroll 1s

Attacks

d20 attack Attack Roll

crit19..20 Crit Range

oncrit double_dice

(attack)^2 Multi-Attack

Commands

let x = 2d8 Save Formula

analyze 3d6 Show Chart

analyze a, b Compare

Discord Bot

/roll d20 adv + 5

/roll analyze 3d6

/roll let smite=2d8

Feature	Dicelab	AnyDice	Google
Probability Charts	✅ Instant	⚠️ Slow	❌
Complex Formulas	✅ Full D&D	✅	❌
Attack Rolls	✅ Crits	❌	❌
Mobile & Offline	✅ PWA	❌	✅
Discord Bot	✅	❌	❌

FAQ

Frequently Asked Questions

Is Dicelab free?

Yes. The Dicelab dice roller and Discord bot are completely free. No signup, no ads, no paywalls.

Why would I use Dicelab?

It combines a powerful dice roller with professional probability analysis. Great for both optimizers and casual players.

What dice notation does Dicelab support?

Standard notation (2d6+3) plus advanced modifiers: advantage (adv), keep highest (kh), drop lowest (dl), reroll (rr), and conditionals.

Can I import my D&D Beyond character?

Yes! Enter your public character URL to generate aliases for all your attacks and abilities automatically.

What is Notebook mode?

A workspace where you can keep multiple roll cells, define variables with let, and build reusable character sheets.

Does Dicelab work offline?

Yes. It's a Progressive Web App (PWA). Once loaded, the WASM engine runs entirely on your device.

How is Dicelab better than AnyDice?

It's faster (runs locally), has cleaner syntax, works on mobile, supports offline play, and includes a Discord bot.

How do I roll with advantage?

Simply type d20 adv. For disadvantage, use d20 dis.

How do I make an attack roll that takes crits into account?

Use (d20 attack + 6) >= 15 ? 2d6 + 4 : 0 and it will double the damage if the attack is a crit.