About the ten-sided die
The d10 is a pentagonal trapezohedron: ten kite-shaped faces, five meeting at each pole. Unlike the d4, d6, d8, d12 and d20 it is not a Platonic solid — no regular polyhedron has ten faces — but every face is identical, so each number still has exactly a 10% chance. Many d10s are numbered 0 to 9, with the 0 read as 10 when the die is rolled on its own; the 3D d10 here prints 1 to 10 so there is nothing to translate. The average roll is 5.5.
What the d10 is used for
- Percentile rolls: a pair of d10s — one read as tens, one as units — gives 1 to 100. See the d100 roller.
- Dice pools: Storyteller games such as Vampire: The Masquerade roll a handful of d10s and count how many beat a target number. Try 5d10 or 10d10.
- D&D: the Fire Bolt and Eldritch Blast cantrips deal 1d10, the heavy crossbow, glaive and halberd deal 1d10, and fighters, paladins and rangers use a d10 hit die.
At least one 10 in a handful of dice
Pool systems often reward each 10 rolled. The chance of seeing at least one is 1 − 0.9n for n dice:
| Rolls | At least one 10 |
|---|---|
| 1 | 10% |
| 2 | 19% |
| 3 | 27.1% |
| 4 | 34.4% |
| 5 | 41% |
| 6 | 46.9% |
| 8 | 57% |
| 10 | 65.1% |
| 15 | 79.4% |
| 20 | 87.8% |
Two d10s added together
| Total | Ways | Chance | Odds | This or higher |
|---|---|---|---|---|
| 2 | 1 | 1% | 1 in 100 | 100% |
| 3 | 2 | 2% | 1 in 50 | 99% |
| 4 | 3 | 3% | 1 in 33.3 | 97% |
| 5 | 4 | 4% | 1 in 25 | 94% |
| 6 | 5 | 5% | 1 in 20 | 90% |
| 7 | 6 | 6% | 1 in 16.7 | 85% |
| 8 | 7 | 7% | 1 in 14.3 | 79% |
| 9 | 8 | 8% | 1 in 12.5 | 72% |
| 10 | 9 | 9% | 1 in 11.1 | 64% |
| 11 | 10 | 10% | 1 in 10 | 55% |
| 12 | 9 | 9% | 1 in 11.1 | 45% |
| 13 | 8 | 8% | 1 in 12.5 | 36% |
| 14 | 7 | 7% | 1 in 14.3 | 28% |
| 15 | 6 | 6% | 1 in 16.7 | 21% |
| 16 | 5 | 5% | 1 in 20 | 15% |
| 17 | 4 | 4% | 1 in 25 | 10% |
| 18 | 3 | 3% | 1 in 33.3 | 6% |
| 19 | 2 | 2% | 1 in 50 | 3% |
| 20 | 1 | 1% | 1 in 100 | 1% |