What was done
Ben Wright reverse engineered Rise of Nations: Extended Edition in Ghidra, wrote a spec per system, and had Claude Code write about 70,000 lines of C++ for OpenRiseOfNations, a playable native macOS engine.
Ben Wright rebuilt the engine of Rise of Nations: Extended Edition, his favourite childhood strategy game, as OpenRiseOfNations, a native macOS app. He studied the original in Ghidra and wrote specs in his own words; Claude Code then wrote about 70,000 lines of C++ from them while he reviewed.
How it was done
The game ships with full debug symbols for its executable. Each subsystem, from terrain and movement to combat, economy, AI and scripting, was reverse engineered and written up in a specification that cites original functions by name and address. Most specs come with a small JavaScript reference tool that reads the game's data. The C++17 code was written from the specs and checked against those tools, often byte for byte: the damage table matches on all 169,312 attacker and target pairs. The README credits heavy use of Claude Code, directed and reviewed by the maintainer, and commits carry a Claude Opus 5.5 co-author line.
Results
The alpha runs on Apple Silicon and Intel Macs with Metal. It loads the tutorials and scenarios, runs the game's own script language through a compatible compiler and virtual machine, and has a computer opponent that builds, expands and attacks. Random maps, multiplayer and saves are not done yet. It reads the art and data from the user's own copy and ships no game files.
