Table of Contents
What Is a Dice Roller?
A dice roller generates random numbers to simulate the rolling of physical dice. Each die is a uniform random number generator that produces an integer between 1 and the number of sides. Virtual dice rollers use pseudorandom number generators (PRNGs) to produce fair results equivalent to physical dice.
Dice rollers are essential in tabletop role-playing games (like D&D), board games, probability education, and statistical simulations. The notation NdS (e.g., 2d6) means rolling N dice with S sides each.
Dice Probability
Expected total = N × (S + 1) / 2
Variance = N × (S² - 1) / 12
When rolling multiple dice, the distribution of their sum forms a bell curve (by the Central Limit Theorem). The more dice you roll, the more closely the total approximates a normal distribution centered on the expected value.
Common Dice Types
| Die | Sides | Common Use |
|---|---|---|
| d4 | 4 | Damage rolls in D&D, caltrops |
| d6 | 6 | Standard die, board games, craps |
| d8 | 8 | Weapon damage in RPGs |
| d10 | 10 | Percentile rolls, World of Darkness |
| d12 | 12 | Greataxe damage in D&D |
| d20 | 20 | Attack rolls, ability checks in D&D |
| d100 | 100 | Percentile rolls, critical hit tables |
Frequently Asked Questions
Are virtual dice truly random?
Virtual dice use pseudorandom number generators (PRNGs), which produce sequences that are statistically indistinguishable from true randomness for practical purposes. JavaScript's Math.random() is sufficient for gaming and educational use, though not for cryptographic applications.
What does 2d6 mean?
The notation 2d6 means rolling 2 dice, each with 6 sides, and summing the results. The general form is NdS, where N is the number of dice and S is the number of sides per die.