Dice Probability Calculator
Calculate the probability of rolling a specific result or higher using standard polyhedral dice. Covers all common tabletop RPG dice: d4, d6, d8, d10, d12, d20, and d100 (percentile).
Probability of Success
Standard Polyhedral Dice Reference
| Die | Faces | Min Roll | Max Roll | Average | Common Use |
|---|---|---|---|---|---|
| d4 | 4 | 1 | 4 | 2.5 | Damage: daggers, magic missiles |
| d6 | 6 | 1 | 6 | 3.5 | Damage: swords, fireball; ability checks |
| d8 | 8 | 1 | 8 | 4.5 | Damage: longswords, rapiers; healing |
| d10 | 10 | 1 | 10 | 5.5 | Damage: heavy weapons; half of d100 |
| d12 | 12 | 1 | 12 | 6.5 | Damage: greataxes; barbarian hit die |
| d20 | 20 | 1 | 20 | 10.5 | Attack rolls, saving throws, ability checks |
| d100 | 100 | 1 | 100 | 50.5 | Percentage chances, random tables |
References & Methodology
- Wizards of the Coast — Dungeons & Dragons 5th Edition Player's Handbook (2014) — Core rulebook defining polyhedral dice conventions, ability check DCs, and the d20 resolution system.
- Anydice.com — Dice Probability Engine — Community-standard tool for tabletop RPG dice probability calculations; methodology validated against analytical combinatorics.
- Feller, W. — An Introduction to Probability Theory and Its Applications, Vol. 1 (Wiley, 1968) — Classical reference for discrete uniform distribution and independent die roll probability calculations.