Dice Notation

Four Against Darkness uses a tiny vocabulary of dice notation.

| Notation | Meaning | |---|---| | d or d6 | Roll one six-sided die. Result: 1–6. | | d8 | Roll one eight-sided die (used in Expert tier / Abyss). | | 2d6 | Roll two six-sided dice and sum them. Result: 2–12. | | 3d6 | Roll three six-sided dice and sum. Result: 3–18. | | d66 | Roll two d6 in order. First die is the tens column, second is the ones. Result: 11–16, 21–26, …, 61–66 — 36 distinct values. Used for room-shape generation. | | d+L | Roll a d6 and add the character's level. | | Nd × Md | Roll one die, multiply by another roll. e.g. 3d6 × 3d6 gp for hidden treasure. |

Why d66, not d36?

d66 reads two six-sided dice positionally. It gives 36 evenly distributed outcomes with the dice you already have. Treat the first die as "tens" and the second as "ones" — 1 then 4 = 14, not 5.

Expert tier

When a party graduates past level 4 into Expert tier (typically by playing Four Against the Abyss), the action die changes from d6 to d8. All Attack, Defense, Search, and Save rolls use d8. Treasure rolls also change die (see each ruleset's table).

Heroic and Legendary

Heroic tier (levels 10–14, Forsaken Depths) uses d10. Legendary tier (15–19) uses d12. The mechanics are identical — just bigger dice.

In the app

The app's dice roller (top-right in delve mode) understands all of this. Type 2d6+3 or d66 and click Roll.