📖 Overview
Compute probability of rolling target sums with two dice across single or repeated sessions.
🧪 Example Scenarios
Use these default and higher-pressure example inputs to explore how sensitive this calculator is before using your real numbers.
| Input | Base Case | Higher Pressure Case |
|---|---|---|
| Number Of Dice | 2 | 2.3 |
| Sides Per Die | 6 | 6.9 |
| Target Sum | 8 | 9.2 |
| Number Of Sessions | 100 | 115 |
⚙️ How It Works
Calculates the exact probability of rolling a specific total with N dice of S sides, then estimates the chance of seeing it at least once across repeated throws.
The Formula
P(exact total) from dice distribution | P(at least once in t throws) = 1 - (1 - p)^t
| N | Number of dice per throw |
| S | Sides per die |
| Target | Desired total sum |
| t | Number of throws |
💡Totals near the center of the range are much more likely than edge totals because more combinations produce them.
Quick Reference
| Dice | Target total | Single throw chance |
|---|---|---|
| 2d6 | 7 | 16.67% |
| 2d6 | 2 or 12 | 2.78% |
| 3d6 | 10 or 11 | 12.50% |
| 3d6 | 3 or 18 | 0.46% |
When To Use This
- Use this tool when you need a fast decision during active planning or execution.
- Use this before committing money, time, or tradeoffs that are hard to reverse.
- Use this to compare options using the same assumptions across scenarios.
Edge Cases To Watch
- Results can be misleading if key inputs are missing, stale, or unrealistic.
- Very small or very large values may amplify rounding effects and interpretation risk.
- If assumptions change mid-decision, recalculate before acting.
Practical Tips
💡 Use this to compare risk for exact-total mechanics and combo triggers.
💡 More throws can make low single-throw odds reasonable over a full game.
💡 Run a best-case, base-case, and worst-case scenario before deciding.
💡 Use recent real values, not ideal assumptions, for better accuracy.
Frequently Asked Questions
❓ Why are edge totals rare?
Only very few face combinations produce minimum and maximum sums.
❓ Does this assume fair dice?
Yes, each face is assumed equally likely and independent.