Custom Skill System

A homebrew dice system designed by Chris, supported natively in FlowDice.

Mechanic

Base roll: 4d[0..5] producing 0–20 on a bell curve (peaks around 10).

Skill modifiers add extra dice. Positive skill keeps the best 4, skewing the distribution right. Negative skill keeps the worst 4, skewing left.

Notation

Skill LevelNotationBehavior
Unskilled (0)4d[0..5]Roll 4, keep all
Skill +15d[0..5]kh4Roll 5, keep best 4
Skill +26d[0..5]kh4Roll 6, keep best 4
Skill +37d[0..5]kh4Roll 7, keep best 4
Skill -15d[0..5]kl4Roll 5, keep worst 4
Skill -26d[0..5]kl4Roll 6, keep worst 4
Skill -37d[0..5]kl4Roll 7, keep worst 4

Die Representation

The base die has faces 0, 1, 2, 3, 4, 5 — a six-sided die starting at zero. In practice this is a standard d6 minus 1, but the app treats it natively as 0–5, eliminating the mental arithmetic.

The d[0..5] notation uses the range syntax (square brackets) rather than listing all faces explicitly.

Distribution Properties

The 4d[0..5] system creates a normal-ish bell curve centered around 10. The Keep Highest and Lowest mechanic warps the distribution without shifting the center — higher skill compresses results toward the top, lower skill compresses toward the bottom. This is the same family as advantage/disadvantage but with a tunable degree.

Template (Phase 2)

The Template Library will include a Custom Skill Check template that prompts for skill level and generates the notation automatically.

See also: Keep Highest and Lowest, Custom Face Values, Notation Spec