What is the D10 Dice Roller?
The D10 Dice Roller is a free online tool that simulates rolling one or more ten-sided dice (D10). Each die yields a uniformly random whole number between 1 and 10. It is ideal for tabletop role-playing games such as the Storyteller/World of Darkness systems, percentile checks, board games, classroom probability demonstrations, or any situation where you need a fair random number without physical dice.
How to use it
Enter how many D10 dice you want to roll (1 to 100) and an optional modifier that is added to the combined total. Click calculate and the tool shows every individual roll, the sum of the dice, your modifier, and the grand total. Refreshing or recalculating produces a brand-new random roll each time.
The formula explained
A single die uses \(\text{roll} = \lfloor \operatorname{rand}() \times 10 \rfloor + 1\), where \(\operatorname{rand}()\) is a random fraction between 0 and 1. Multiplying by 10 and flooring gives 0–9, and adding 1 shifts the range to 1–10. The final total is the sum of all dice plus your modifier: $$\text{total} = (\text{roll}_1 + \text{roll}_2 + \dots + \text{roll}_n) + \text{modifier}$$
Worked example
Suppose you roll 3 dice and they land on 4, 9, and 2, with a modifier of +5. The sum of the dice is \(4 + 9 + 2 = 15\). Adding the modifier gives \(15 + 5 = 20\), your total result.
FAQ
Are the rolls truly random? They use a pseudo-random number generator, which is fair and unpredictable for everyday gaming and learning purposes.
Can the modifier be negative? Yes. Enter a negative number and it will be subtracted from the dice total.
What is the maximum I can roll? You can roll up to 100 dice at once, for a maximum dice sum of 1000 before any modifier.
