rpg-dice-roller

rpg-dice-roller allows you to simulate dice rolls with modifiers and mathematical expressions.
This crate is inspired by and based on the popular JavaScript library rpg-dice-roller, please check out their wonderful documentation for more details on the functionality provided by the library.

Installation

cargo add rpg-dice-roller

Example Usage

use rpg-dice-roller::roll;

// Roll 4 d10.
let rolled = roll("4d10")?;
println!("{rolled} = {}", rolled.value()); // [3, 2, 3, 3] = 11

// Roll 3 d20, make the minimum value 5, keep the lowest 2 rolls.
let rolled = roll("3d20min5kl2")?;
println!("{rolled} = {}", rolled.value()); // [6, 5^, 17d] = 11

// Roll a group of 3 expressions:
// 3d100,
// 3 fudge dice (d6s with 2 -1 sides, 2 +1 sides and 2 blank ones) and add 5 to the result,
// 1 d50 and evalate its result to the power of 2
// Count the number of expressions whose value was greater than 50
let rolled = roll("{3d%, 3dF.2 + 5, pow(d50, 2)}>50")?;
println!("{rolled} = {}", rolled.value()); // {[68, 8, 31]*, [1, 1, 1] + 5, pow([14], 2)*} = 2

Supported Die kinds

More details on the dice kind documentation

• Any dice until u32::MAX number of sides
• Fudge/Fate die with 4 blank sides, 1 plus side and 1 minus side.
• Fudge/Fate die with 2 blank sides, 2 plus sides and 2 minus sides.

Supported Modifiers

More details in the modifier documentation

• Min/Max
• Exploding/Penetrating/Compounding/PenetratingCompounding
• Reroll/Reroll once
• Unique/Unique once
• TargetSuccess/Failure
• CriticalSuccess/Failure
• Keep/Drop
• Sort

Supported expressions

• Addition +, subtraction -, multiplication *, division /, remainder %, power ^ or **.
• abs(), floor(), ceil(), round(), sign(), sqrt(), log(E), exp(), sin(), cos(), tan().
• min(_, _), max(_, _), pow(_, _).
• operation precedence between operators and parethesis.
• Groups {} will sum (or apply target success/failure if modifiers were applied) to the comma separated expressions inside.

Rng

This crates uses rand::thread_rng() by default but provides _with functions (roll_with, Dice::roll_once_with(), etc.) so you can use anything the rand::Rng trait with them.