A No-Frills Introduction to Lua 5.1 VM Instructions (2006) [pdf]

This is also the best internal opcode description for the LUA derived VM's: potion[1], sol[2] and tinyrb[3].

1: http://perl11.org/potion/

2: https://github.com/rsms/sol

3: http://code.macournoyer.com/tinyrb/

This is pretty cool. Is there something like this for the LuaJIT VM?

I read this guide ALOT when trying to understand how a VM worked, this guide was invaluable. It gave me enough knowledge to write my own VM. Recommended!

Let me guess, you were playing Hack 'n' Slash, and the control flow statements didn't make sense.