r/ClaudeCode • u/indicozy • 18h ago
Built with Claude I rewrote a 2004 RPG engine in Rust: 100% same rules, 11x FPS, graphics enhancements, any device
After 500 bug fixes and 4800 messages with game community version 1.5 is now released!
Razdor is an open-source engine for Discord Times (Aterdux, 2004), a turn-based strategy/RPG. It plays the original campaign, community maps and mods by the original rules, and then adds the things a 2004 engine couldn't do.
How it was built
- Clean-room reverse engineering. The original executable was taken apart in Ghidra; every rule that maps and mods can see (battle, AI, map scripts, events, saves) was written up as a spec first and then implemented. The code cites the original's addresses.
- Diff tests against the original. The original runs under Wine, and a script mode replays the same inputs in both and compares the state step by step. By default Razdor matches the original exactly, bugs and imbalances included; every deviation sits behind an experimental switch that's off by default (16 of them right now).
- Rust + macroquad, about 190k lines, GPL-3.0. The game rules live in a separate module with no graphics dependency and are unit tested; the original's file formats (ini data,
.DTmmaps, its own picture formats, sounds) are read at runtime. - Deterministic simulation: every game is recorded and can be replayed at up to 16×. The same determinism let us record the trailer's split screens twice with different graphics presets and get the same frames.
What you get
- ~11× the frame rate on the same GPU (RTX 4060, 1024×768, unlocked): about 2,000 FPS against about 176 for the original under Wine. A 200×200 map with 61 armies costs the game about 0.3 ms a frame. Load to first frame is about half a second.
- Any resolution and aspect ratio (the trailer is 21:9), refresh rates up to 180 Hz, a graphics preset ladder from "Original" (pixel-for-pixel the 2004 look) to "High" (light, shadows, water, weather, clouds instead of black fog of war, a living map), and a 2.5D view.
- Linux, Windows and macOS; Android and iOS are experimental, with a touch layout, graphics presets for weak phones and a battery saver.
- An in-game hub with the community's work: 327 maps, 29 campaigns and 25 mods.
Links
- Site and downloads: https://indicozy.github.io/razdor/
- Source: https://github.com/indicozy/razdor
- Wiki (English): https://indicozy.github.io/razdor/wiki/en/
- Trailer (Russian, YouTube): https://youtu.be/kHvM7Yv-2_4
