A deterministic randomization toolkit with seeded streams, statistical distributions, and gameplay selection systems.

Designed for gameplay systems that require repeatable results, isolated substreams, loot control, and procedural logic. Seeded Streams • Statistical Distributions • Gameplay Selection Systems • Deterministic Shuffle • Bag Fairness | Same Starting State + Same Inputs + Same Call Order = Same Results

Full explanation in documentation PDF.

Add RNG³ nodes → Create or Seed Stream → Draw / Fork / Build

RNG³ is a deterministic randomization toolkit for Unreal Engine that gives Blueprint users seeded streams, weighted selection, float distributions, deterministic shuffling, index sampling, and shuffled bags that use every item once per cycle. Build repeatable gameplay systems, isolate loot, AI, and procedural logic into separate substreams, and keep your Blueprint graphs organized.

100% FREE FOR THE UNREAL ENGINE DEVELOPER COMMUNITY!!

PLEASE PURCHASE THE PROFESSIONAL VERSION OF THE PLUGIN AS THE PRICE IS THE SAME AS THE PERSONAL VERSION
ONCE YOU HAVE THE SOURCE FILES, YOU ARE FREE TO USE, MODIFY, AND REDISTRIBUTE THEM IN ANY PROJECT, PERSONAL OR COMMERCIAL, UNDER THE OPEN SOURCE LICENSE IN EACH FILE HEADER.

Randomization Methods

Use one seeded stream for a system, fork it into deterministic substreams, or combine selection methods to suit your gameplay.

• Seeded Deterministic Streams

• Forked Substreams

• Weighted Selection

• Float Distributions: Uniform, Triangular, Clamped Normal, and Bounded Exponential

• Deterministic Shuffling and Index Sampling

• Shuffle Bags: Every Item Once per Complete Cycle

• Chance Checks Using Uniform Draws and Thresholds

Usage

Use one seeded stream for a system, or fork it into separate deterministic substreams.

1. Stream Variable [Required]

• Initialize with RNG³ Seed Stream or RNG³ Make Stream, then retain the variable between draws.

2. Bag State [Required for bag draws]

• Retain the bag state between calls to preserve the remaining items and repeat history.

3. Sequence [Stream setup]

• Selects the generator sequence for a seed. Keep it consistent when reproducing results.

4. Label / Child Sequence [Fork setup]

• Configure deterministic substreams. Matching forks require the same parent state, Label, and Child Sequence.

Features

• Blueprint-callable tools for deterministic gameplay randomization

• Seeded streams with debug-visible Seed, Sequence, and Draw Count

• Deterministic stream forking using Labels and Child Sequences

• Separate substreams for isolating loot, AI, procedural generation, and other systems

• Ranged integer and float draws, plus raw 32-bit random values exposed through int32 pins

• Float distributions: Uniform, Triangular, Clamped Normal (Gaussian), and Bounded Exponential

• Weighted index selection for loot tables, rarity tables, and probability-driven choices

• Deterministic Fisher-Yates shuffling for repeatable ordering

• Index sampling with or without replacement

• Shuffle bags that use every item once per complete cycle, with a best-effort repeat-avoidance window

• SaveGame-compatible stream and bag state for resuming random sequences

• Suitable for loot systems, AI variation, spawn selection, procedural events, card draws, playlists, and reproducible replay workflows

• Includes one example Blueprint and one example level

• Runtime implemented entirely in C++, with 14 Blueprint-callable functions

Note: Most issues arise from changing call order, modifying sequence values, or mixing multiple gameplay systems into the same stream.