Laravel RNG

Deterministic, stream-isolated RNG for Laravel using PHP's native Random extension. Ideal for games, simulations, and reproducible seeding pipelines.

Installation

composer require christhompsontldr/laravel-rng

Configuration

Publish the config file:

php artisan vendor:publish --tag=rng-config

Environment variables:

Basic Usage

use Rng\RngManager;

$rng = app(RngManager::class);
$stream = $rng->for('my_stream');

// Integer in range (inclusive)
$roll = $stream->int(1, 20);  // d20

// Boolean with probability (0.0 - 1.0)
$hit = $stream->chance(0.75);  // 75% hit chance

// Pick one item from array (uniform)
$item = $stream->pick(['sword', 'shield', 'potion']);

Streams are isolated: seeding and combat produce independent sequences from the same master seed.

RPG Seeding Example

Reproducible unit generation for a low-fantasy game:

use Rng\RngManager;

$rng = app(RngManager::class);
$seeding = $rng->for('seeding');

$archetypes = ['scout', 'heavy', 'mixed'];
$units = [];

for ($i = 0; $i < 25; $i++) {
    $arch = $seeding->pick($archetypes);
    $cp = $seeding->int(60, 90);
    $ipBudget = 100 - $cp;
    $units[] = compact('arch', 'cp', 'ipBudget');
}
// Same master seed → same 25 units every run

With a database factory (e.g. Newland UnitFactory):

$rng = app(RngManager::class);
$seeding = $rng->for('seeding');

for ($i = 0; $i < 25; $i++) {
    $arch = $seeding->pick(['scout', 'heavy', 'mixed']);
    $cp = $seeding->int(60, 90);
    UnitFactory::new()
        ->lowFantasy()
        ->archetype($arch)
        ->cpValue($cp)
        ->create(['ip_budget' => 100 - $cp]);
}

Combat Example

Deterministic combat rolls per turn:

$rng = app(RngManager::class);
$combat = $rng->for('combat');

// Initiative
$initiative = $combat->int(1, 20);

// Attack roll
$attackRoll = $combat->int(1, 20);

// Damage
$damage = $combat->int(2, 12);

// Hit chance (e.g. 65%)
$hit = $combat->chance(0.65);

When rng.logging is true, each roll is logged with stream name, roll index, type, and result. Run php artisan rng:audit to inspect.

Testing

Override the master seed in tests for predictable fixtures:

// In setUp() or test
config(['rng.default_master_seed' => 42]);

$rng = app(RngManager::class);
$stream = $rng->for('seeding');
$arch = $stream->pick(['scout', 'heavy']);  // Deterministic

Or inject directly when not using the container:

$manager = new \Rng\RngManager(42);
$stream = $manager->for('seeding');

Use rng:test-seed to generate a sample roll sequence for fixtures:

php artisan rng:test-seed
# Seed: 42
# [16, 4, 13, 19, 1]

php artisan rng:test-seed 12345
# Seed: 12345
# [19, 7, 14, 18, 20]

Artisan Commands

Requirements

• PHP 8.4+
• Laravel 12+

License

MIT