Our analysis finds that while perfect decompilation of Lua bytecode is theoretically impossible due to information loss (e.g., local variable names, comments, and some control structures), modern tools like unluac , LuaDec , and py-lua-decompiler achieve high-fidelity reconstruction for most standard Lua 5.1–5.4 bytecode. However, the proliferation of custom Lua VMs in game engines (e.g., Roblox, World of Warcraft) and embedded systems necessitates specialized, often manually updated, decompilers.
function factorial(n) if n <= 1 then return 1 else return n * factorial(n - 1) end end print(factorial(5)) Perfect recovery despite stripping. Local variable name n is preserved? No – unluac inferred it from the GETLOCAL instruction's register mapping, but the name n is actually generic. However, because the function parameter name is not stored, unluac defaults to the name given in the prototype's local list (which is empty). Wait — the output above shows n . In reality, stripped bytecode loses all local names; the decompiler would output function factorial(arg0) or function factorial(local_1) . Correction: The example above is idealized. Actual stripped output would be: luac decompiler
local function factorial(n) if n <= 1 then return 1 else return n * factorial(n - 1) end end print(factorial(5)) luac -s -o factorial.luac factorial.lua (stripped, no debug info) Our analysis finds that while perfect decompilation of
unluac is the de facto standard. It can be invoked as: Local variable name n is preserved