Metatables

Metatables are extra tables attached to data types such as tables, userdata, and even strings (Although you can't change the string metatable in Roblox) which describe how they behave in certain situations when a script tries to manipulate them.

To create a pseudoclass with Lua, you simply want to make a constructor which makes a new table and forces it to inherit from a class table.

local Object = {};
function Object:new(...) -- Sugar for Object.new = function(self, ...)
    return setmetatable({...}, self)
end
Object.__index = Object
function Object:Print()
    for k,v in next, self do
        print(k,v)
    end
end

local List = Object:new("This", "Is", "Basic")
Object:Print()
--> 1 This
--> 2 Is
--> 3 Basic