3D6 Roller
Rolling 3D6 produces a total between 3 and 18 with an expected average of 10.5. Totals 10 and 11 are tied for the highest probability at 12.50% each.
âš™ Advanced Expression (NdM±K) â–¼
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Roll History
0Exact Mathematical Probability
Combinatorial EngineCalculates discrete binomial distributions, probability density, and cumulative odds for the active dice expression.
View Full Probability Table & Combinations â–¼
| Total | Ways | Exact % | ≥ At Least | ≤ At Most |
|---|
Roll N Times (Multi-Trial Simulation)
Execute up to 10,000 repeated trials to calculate empirical distributions and statistics.
Empirical Frequency Table
| Roll Total | Hits (Count) | Frequency Bar | Percentage |
|---|---|---|---|
| Click "Run Trials" to simulate rolls and generate frequency data. | |||
Probability Curve & Mathematical Mechanics
The 3D6 roll produces a genuine bell curve approximation. Standard in classic tabletop stat rolls and systems like GURPS, rolling three dice creates an organic distribution where moderate results (9 through 12) occur almost 50% of the time, while extremes (3 or 18) are rare miracles.
There are 6 × 6 × 6 = 216 total permutations. A 10 or 11 each have 27 combinations (12.5% each). A perfect 18 or minimum 3 each have only 1 combination (1 in 216, or 0.46%).
Prominent Tabletop Games Using 3D6
- • GURPS core skill and combat resolution system (roll under skill rating)
- • Classic "3d6 down the line" RPG ability score generation (Strength, Dex, Con, Int, Wis, Cha)
- • Fudge / Fate conversion comparisons
- • Hero System action checks
3D6 Distribution Overview
| Total Sum | Permutations | Exact Probability |
|---|---|---|
| 3 | 1/216 | 0.46% |
| 6 | 10/216 | 4.63% |
| 9 | 25/216 | 11.57% |
| 10 | 27/216 | 12.50% |
| 11 | 27/216 | 12.50% |
| 12 | 25/216 | 11.57% |
| 15 | 10/216 | 4.63% |
| 18 | 1/216 | 0.46% |