Every face has a 1 in 8 chance — 12.5% each. Average roll: 4.5.
The d8 is the quiet middle of the polyhedral set. It is not the star like the d20 and not the familiar cube, but it turns up constantly: the longsword, the rapier, the longbow, the healing spell, the hit die for half the classes in the game.
Its shape is the octahedron — two square pyramids joined base to base, eight equilateral triangles in total — and it is one of the better-behaved dice in the set, tumbling freely without the d20’s habit of continuing off the edge of the table.
In fifth-edition DnD a handful of weapons carry the "versatile" property: they deal one damage die in one hand and a larger one in two. The longsword, battleaxe and warhammer all deal 1d8 one-handed and 1d10 with both. That single property is why a d8 is in the hand of almost every sword-and-board fighter and paladin at the table.
It sits in a deliberate sweet spot. A d6 weapon is fast and usually light or finesse; a d10 or d12 weapon demands both hands and gives up a shield. The d8 is the die you roll when you have made neither compromise.
Hit dice decide how much health a character gains each level, and the d8 is the most common one in the game. Bards, Clerics, Druids, Monks, Rogues and Warlocks all use it — which is to say most of the classes that are neither front-line tanks nor pure spellcasters.
The same die does the healing. Cure Wounds, Healing Word and Lay on Hands are all counted in d8s, so a cleric can spend a whole session rolling d8s for damage, d8s for healing, and d8s again on a short rest.
Like the d6, the d8 follows a pairing convention: opposite faces add up to nine. 1 faces 8, 2 faces 7, 3 faces 6, 4 faces 5. Because the die reads from the top face there is never any ambiguity about the result, the way there is with a d4.
The octahedron is one of the five Platonic solids, which is why the polyhedral set is shaped the way it is. The d4, d6, d8, d12 and d20 are exactly those five solids — the d10 is the odd one out, and it had to be invented.
Bards, Clerics, Druids, Monks, Rogues and Warlocks. That makes the d8 the most common hit die in the game — it covers everything between the d6 spellcasters and the d10 and d12 front-liners.
It means the weapon deals 1d8 used in one hand and 1d10 when you use both. Longswords, battleaxes and warhammers all work this way, so the real choice is between carrying a shield and rolling a bigger damage die.
No. 1d8 spreads evenly from 1 to 8 and averages 4.5. 2d4 runs from 2 to 8, averages 5, and peaks sharply at 5. The d8 is swingier; 2d4 is steadier and slightly higher.
Seven dice come in the set and new players are told to buy them before anyone explains what they do. This is what each one is for.
Every rulebook writes rolls in the same compact shorthand. Here is how to read it, including the keep and drop notation that trips people up.
The maths behind why some rolls feel reliable and others feel like coin flips — with the numbers you can actually use at the table.
Last updated: August 20, 2026
