Dice Roller

📊 Probability of Each Sum — Two Six-Sided Dice

🎲 About This Dice Roller

This free online dice roller simulates all standard tabletop RPG dice: d4, d6, d8, d10, d12, d20, and d100. Whether you play Dungeons & Dragons, Pathfinder, Shadowrun, Call of Cthulhu, or any board game requiring dice, this tool gives you instant fair random results without needing physical dice. Roll single dice, multiple dice at once, add modifiers, and use advantage or disadvantage mode — all in one place.

The roller uses JavaScript's Math.random() seeded from system entropy for statistically fair results on every roll. Each roll is completely independent with no memory of previous results. Roll history is displayed below each result so you can see individual dice outcomes and the total sum.

📜 History of Polyhedral Dice

Polyhedral dice date back to ancient Egypt and Rome — icosahedral (20-sided) dice made of serpentine have been found from around 2nd century BCE Egypt, used for divination and games. The modern set of 7 polyhedral dice was popularized by Dungeons & Dragons, first published by Gary Gygax and Dave Arneson in 1974 through TSR Inc. The original game used unconventional dice shapes that were hard to find commercially, eventually leading Gygax to partner with game manufacturer Lou Zocchi to produce the now-standard d4, d6, d8, d10, d12, d20, and d100 set. Today, polyhedral dice are used in hundreds of tabletop RPG systems worldwide, with the d20 becoming the iconic symbol of the hobby.

🏆 CPS Ranking Guide

🎯 Common Uses

• Dungeons & Dragons — attacks, skill checks, saving throws, damage
• Pathfinder & other RPGs — all standard polyhedral dice systems
• Board games — any game requiring custom or standard dice
• Character creation — rolling 4d6 drop lowest for ability scores
• Random number generation — fair random results for any use case
• Online play — virtual tabletop sessions without physical dice
• Teaching probability — demonstrate dice distribution and statistics

🧭 How to Use This Dice Roller

1. Select your dice type — d4, d6, d8, d10, d12, d20, or d100
2. Set number of dice — roll 1 to 20 dice simultaneously
3. Add a modifier — optional positive or negative bonus
4. Choose mode — normal, advantage, or disadvantage
5. Click Roll Dice — see each die result and total instantly

⚠️ Common Mistakes

• Assuming small samples reflect true probability — rolling a die 10 times can look "unfair" even with a perfectly random generator; probability only evens out over large samples.
• Confusing independent rolls with dependent odds — each dice roll is independent; a string of 6s does not make another 6 less likely next roll.
• Using the wrong die type for the game rule — always check whether a tabletop game calls for d6, d20, d10, or another die before rolling.

🔗 Related Calculators

❓ What is a d20?

A d20 is a 20-sided die used primarily in Dungeons & Dragons and other tabletop RPGs. It determines the outcome of attacks, skill checks, and saving throws. Rolling a natural 20 is a critical hit, while rolling a 1 is a critical failure. The d20 is the most iconic die in modern tabletop gaming and the symbol of the D&D hobby worldwide.

❓ What does rolling with advantage mean?

Rolling with advantage means you roll two d20 dice and take the higher result. Disadvantage means you take the lower result. Both are core D&D 5th Edition mechanics. Advantage is granted by spells, class abilities, and favorable situations. Disadvantage applies when conditions work against you. This system replaced the older +2/-2 flat modifier approach.

❓ What is a d100 (percentile dice)?

A d100 generates a random number from 1 to 100 for percentage-based outcomes. Traditionally rolled using two 10-sided dice — one for tens, one for units. A roll of 00 and 0 equals 100. Our roller simulates a true d100 instantly. Used in Warhammer, Call of Cthulhu, and many RPG wild magic tables.

❓ Can I roll multiple dice at once?

Yes — roll 1 to 20 dice simultaneously with individual results and total sum displayed. Rolling 4d6 (four six-sided dice) is the standard D&D method for generating ability scores. Select d6, set quantity to 4, and click roll to see all four results plus total instantly.

❓ What is a modifier in dice rolling?

A modifier is a fixed number added to or subtracted from your dice total. A +3 Strength modifier adds 3 to every Strength-based attack roll. Modifiers come from character stats, proficiency bonuses, spells, and equipment. Enter your modifier in the field before rolling and it is automatically included in your total result.

❓ What dice do I need for D&D?

Standard D&D requires 7 polyhedral dice: d4, d6, d8, d10, d12, d20, and d100. The d20 is used most frequently for checks and attacks. The d6 is used for common weapons and the classic 4d6-drop-lowest ability score method. Our roller simulates all 7 types perfectly for online or hybrid play.

❓ What is a critical hit in D&D?

A critical hit occurs on a natural 20 attack roll. You roll all damage dice twice and add modifiers once. Example: a dagger normally dealing 1d4+2 deals 2d4+2 on a crit. Some class features lower the crit threshold to 19 or 18. A critical failure (natural 1) automatically misses regardless of modifiers.

❓ How does the dice roller ensure fair results?

Our roller uses JavaScript Math.random() seeded from system entropy for statistically fair results. Each roll is completely independent with no memory of previous rolls — no patterns or biases. While true hardware random number generators offer cryptographic randomness, our roller produces excellent fair results for all tabletop gaming purposes.