Reverse engineering for mods

Rule zero: read the real thing, don't guess. Decompiled code, the actual data, a live memory view or a GPU capture is the spec. Write what you learn into MODLOG.md (names, IDs, offsets, formats) as you go.

Keep all decompiled output and extracted assets outside the mod repo (e.g. ~/<game>-decomp/) and never publish them. Single-player, offline or servers the user runs. Never attach debuggers or scanners to games with anti-cheat (see skills/mod-any-game/references/safety.md).

Pick the tool by what the code is (um scan tells you)

Managed .NET (XNA/FNA, Unity Mono, most indie C#)

• dotnet tool install -g ilspycmd, then ilspycmd -p -o ~/<game>-decomp <Game>.exe (or Assembly-CSharp.dll). This gives a full C# project you can grep.
• dnSpyEx: step through with a debugger, set breakpoints, edit methods.
• MCP: ILSpy-MCP / dnspy-mcp let an agent query types and methods directly.