Understanding the Better Runtime Resource Pack (BRRP) Mod
If you have ever worked on a large Minecraft mod with dozens of similar blocks, you know the pain of creating endless JSON files. Every block demands a loot table, a blockstate definition, at least one block model, an item model, and often a recipe. That means at least five JSONs per block. Multiply that by a hundred blocks, and the repetitive work can feel endless. The Better Runtime Resource Pack, or BRRP, is a library mod that completely changes this workflow by generating those resources at runtime, directly inside the game instance.
What Exactly Is a Runtime Resource Pack?
In vanilla Minecraft and traditional modding, all assets and data files are serialized — stored as JSON text inside the mod’s JAR file or in a separate resource pack. The game reads those files, deserializes them, and turns them into in-game objects. A runtime resource pack (RRP) skips the step of storing pre-written JSONs. Instead, your mod code creates objects that represent blocks, items, loot tables, and models. BRRP then serializes those objects into the byte form the game expects, all while the game is running. The result is that you never have to manually write those repetitive JSONs again.
Traditional vs. Runtime Resource Packs
To see the difference clearly, here is the data flow for both approaches:
- Traditional: File on disk → byte form → deserialized in-game objects
- Runtime: Mod code → ARRP/BRRP objects → serialized to byte form → deserialized in-game objects
While runtime generation adds a serialization step that traditional packs avoid, the trade-off is massive: you eliminate hours of manual JSON creation and shrink your mod file size dramatically. Textures are still stored as image files, because generating them at runtime is impractical, but everything else can be automated.
Why BRRP Is a Game-Changer for Mod Developers
BRRP is a direct fork of the well-known Advanced Runtime Resource Pack (ARRP) mod, preserving all its features while refining compatibility and long-term maintainability. If your mod already depends on ARRP, you can switch to BRRP seamlessly. The game will launch without issues, and all existing ARRP-dependent mods will continue to function. BRRP even allows ARRP-dependent mods to run when only BRRP is installed, though you should never install both at the same time. Some mods embed ARRP inside their JARs, which can cause conflicts, so it is recommended to avoid nesting BRRP into your own mod file.
One of the smartest design choices in BRRP is its commitment to backward compatibility. No classes, fields, or methods have been deleted from the ARRP codebase — they are simply deprecated. This means mods that rely on ARRP’s internals or apply Mixins to it have a much lower chance of breaking when running on BRRP. For modpack creators and server owners, this translates into a smoother experience with fewer crashes.
How BRRP Handles Repetitive Tasks Automatically
Consider a simple stone-like block. Its loot table is almost always “drop itself.” If you need Silk Touch, the condition is trivial. For a slab, breaking the double variant drops two slabs. Writing these loot tables manually is tedious. BRRP lets you define a template in code and generate all variants automatically. The same applies to block models: you can create parent models and let the library produce child models with different textures or rotations. The result is a cleaner codebase and far fewer files to manage.
Installation and Compatibility Notes
Starting from version 1.0.0, the mod ID changed from better_runtime_resource_pack to brrp_v1. This change breaks compatibility with older versions, but the new ID allows both old and new versions to coexist if absolutely necessary. Unless you have a specific reason, you should always use the latest version. The mod is open-source under the MPLv2 license, and you can find it on major mod hosting platforms. For a hassle-free setup, many players now manage their mods through the foxygame.net launcher — a convenient, flexible, and modern Minecraft launcher where you can download mods right from the menu, ensuring you always get the correct version and dependencies without manual file hunting.
Performance Considerations and Future Plans
Because BRRP serializes objects at runtime, there is a slight performance overhead compared to pre-serialized files. However, this is rarely noticeable during normal gameplay, and the development time saved is enormous. The mod’s creator has a long-term goal to eliminate the serialization-deserialization cycle entirely, allowing the game to use generated objects directly. While this is already theoretically possible, it requires more research to keep the system compatible with traditional resource packs and data packs that might override runtime content.
When Should You Use BRRP?
BRRP is ideal for any mod that adds a large number of blocks or items with similar properties — think building mods, tech mods with many machine tiers, or decoration packs. If you are a modpack author, you do not need to use BRRP directly, but you should be aware that many mods now rely on it. Ensuring BRRP is installed can prevent missing resource errors and improve loading times. It also reduces the overall size of your mods folder because the generated JSONs never need to be stored as loose files.
Final Thoughts
Better Runtime Resource Pack is more than just a library — it is a smarter way to build Minecraft mods. By moving resource generation from your hard drive into the game’s runtime, it slashes development time, reduces file clutter, and keeps your mod lightweight. The careful fork from ARRP ensures that existing projects can adopt it with minimal friction, while the open-source nature guarantees community-driven improvements. Whether you are a seasoned modder tired of JSON repetition or a player wanting to understand why some mods require this library, BRRP represents a significant step forward in Minecraft modding efficiency.