📖 Overview
Use this calculator to model dice reliability for board game checks and combat turns.
⚙️ How It Works
Estimates the chance of getting at least one successful face across multiple dice and repeated rolls.
The Formula
P(at least 1 success) = 1 − (1 − s/f)^(dice × rolls)
| s | Number of successful faces on each die |
| f | Number of faces per die |
| dice | How many dice are rolled each attempt |
| rolls | How many attempts are made |
Quick Reference
| Scenario | Success chance |
|---|---|
| 1 success face on d6, 2 dice, 1 roll | 30.56% |
| 1 success face on d6, 2 dice, 3 rolls | 66.50% |
| 2 success faces on d6, 3 dice, 2 rolls | 91.22% |
| 3 success faces on d8, 4 dice, 2 rolls | 95.91% |
Practical Tips
💡 Increase either number of dice or number of rolls to quickly improve reliability.
💡 This assumes each die outcome is independent and fair.
Frequently Asked Questions
❓ Why does the chance rise so fast with more dice?
Each additional die adds another independent chance to hit success.
❓ Can successful faces be greater than sides?
No, successful faces must be less than or equal to die faces.