The d8, properly introduced
Eight-sided dice are ancient too: octahedral examples survive from Ptolemaic Egypt and Rome, some inscribed with letters for divination rather than numbers for play. The modern d8 arrived in game shops with the first Dungeons & Dragons boxed sets in the mid-1970s, sold as part of the now-standard polyhedral family.
Roll it for: weapon damage in tabletop rpgs; eight-way random choices; teaching probability with a non-cube die. And if the d8 isn't the die your game asks for, the full dice roller has the other five.
- 8, numbered 1 to 8
- Octahedron, a Platonic solid
- 12.5% — exactly 1 in 8
- 4.5
- averages 9; totals range 2 to 16
- two 8s in a row: 1 in 64
D8 — frequently asked
A 8-sided die shaped as a octahedron, one of the five Platonic solids. Two pyramids glued base to base. Faces are numbered 1 to 8, and on a fair d8 each lands with exactly a 12.5% chance.
One in 8, or 12.5%, the same as every other face. Rolling two 8s back to back happens once in 64 attempts. The roller here uses rejection sampling on a cryptographic generator, so those odds hold exactly.
4.5. A fair die averages the midpoint of its range, so 2×d8 averages 9 and 3×d8 averages 13.5. Single rolls are flat: an average result is no more likely than a 8 or a 1.
Weapon damage in tabletop RPGs; Eight-way random choices; Teaching probability with a non-cube die. Beyond those, any decision with 8 options maps onto it directly.