Lua Metatables Tutorial

“In this tutorial I’ll be covering a very important concept in Lua: metatables. Knowledge of how to use metatables will allow you to be much more powerful in your use of Lua. Every table can have a metatable attached to it. A metatable is a table which, with some certain keys set, can change the behaviour of the table it’s attached to…”

http://nova-fusion.com/2011/06/30/lua-metatables-tutorial/