Random Dice Roller
Input one dice expression per line (NdS format) to roll multiple dice groups at once. Perfect for tabletop sessions or probabilistic experiments.
Format: NdS (N dice, S sides). Example lines: 3d8, 1d12, 4d4.
How to Use This Calculator
- Enter one NdS expression per line (e.g., 3d6, 2d10).
- Press “Roll dice” to generate random results for each expression.
- Review individual results and totals for each dice group.
- Use grand total for combined outcomes in games or simulations.
Formula
Each die roll ~ Uniform(1, S)
Expected value per die = (S + 1) / 2
Total expected value for NdS = N × (S + 1) / 2
Variance per die = (S² − 1) / 12; total variance = N × (S² − 1) / 12
Full Description
The random dice roller allows rolling multiple dice groups simultaneously. It mirrors the NdS notation common in tabletop RPGs, enabling quick simulation of complex dice pools.
Frequently Asked Questions
Can I mix different dice in one line?
Each line represents one dice type. Use separate lines for different NdS expressions.
Are results independent?
Yes. Each die uses a uniform pseudo-random generator for independent outcomes.
Is there a limit on number of dice?
Extremely large counts may impact performance. Keep values reasonable for best responsiveness.
How do I include modifiers?
Add modifiers manually after rolling or add a separate expression (e.g., 1d1 for +1).