The pkmn/engine project, an ambitious open-source Pokemon battle simulator written in Zig, has sparked heated discussions about how faithfully modern implementations should recreate the bugs and quirks of original Pokemon games. Currently supporting only Generation 1 mechanics, the engine aims to provide a high-performance alternative to existing simulators while grappling with fundamental questions about game authenticity.
Technical Requirements:
- Language: Written in Zig with TypeScript bindings
- APIs: C API and JavaScript/TypeScript support
- Compatibility: Requires specific Zig compiler versions (before 0.12.0-dev.876+aaf46187a recommended)
- License: MIT License
The Authenticity Dilemma
The core debate centers on which original game bugs should be preserved and which should be fixed for better gameplay. The engine's developers have taken a nuanced approach, choosing to reproduce bugs that stem from specific effect implementations while avoiding those caused by fundamental mechanical misunderstandings or architectural limitations.
Community members are particularly divided on several notorious Generation 1 bugs. Issues like multiplayer desyncs, invulnerability exploits during Fly and Dig moves while paralyzed, and the broken Focus Energy mechanic present difficult choices. Some argue these bugs are essential to authentic gameplay, while others contend they harm the player experience without adding meaningful value.
Bugs like normal body slam para invuln, amnesia reapplying speed drops, and toxic counter bugs, 1/256 miss chance, focus energy bugs, I would expect to stay. If those get fixed, the project would veer into the terrain of natdex, Create A Pokemon, or Custom Metas, as in made up fan games that never existed in cartridge
Technical Architecture and Performance Goals
The project's multi-language approach combines Zig for core performance with TypeScript bindings for web accessibility. This design choice aims to deliver the computational speed needed for AI training and tournament simulations while maintaining broad compatibility across platforms. The engine exposes both C APIs for native integration and JavaScript interfaces for browser-based applications.
However, the project currently requires specific Zig compiler versions due to ongoing compatibility issues, highlighting the challenges of building on rapidly evolving toolchains. The developers have included compiler patches directly in their source tree, suggesting they're working around active bugs in the Zig ecosystem.
Development Roadmap and Current Limitations
The engine follows a staged development approach, with foundational work largely complete and Generation 1 and 2 implementations currently in progress. The team has explicitly ruled out certain features including custom rule enforcement, battle variants beyond standard formats, and first-class support for game modifications.
This focused scope reflects a pragmatic approach to a complex problem space, but it also means the engine won't serve users looking for extensive customization options or non-standard gameplay modes.
Development Stages:
- Stage 0: Documentation, integration, benchmark, protocol (mostly complete)
- Stage 1: RBY & GSC implementation (in progress)
- Stage 2: ADV & DPP
- Stage 3: Modern generations
Community Reception and Future Prospects
The project has attracted attention from both competitive Pokemon players and developers working on AI agents for Pokemon battles. The MIT licensing and C API availability have been particularly well-received by developers who want to integrate the engine into commercial projects without copyleft restrictions.
As the engine progresses through its development stages, the ongoing authenticity debate will likely intensify. The team's decisions about which historical bugs to preserve will significantly impact the engine's adoption in different communities, from speedrunners seeking perfect accuracy to competitive players prioritizing balanced gameplay.
The pkmn/engine represents an interesting case study in how modern developers approach legacy game systems, balancing historical fidelity with contemporary usability expectations.
Reference: pkmn/engine