gistfile1.lua

local class = {} -- Since you're returning this at the end, I assume you want it local to the file

-- Problem is, you can only have this file run once, or otherwise remove the "local" but then you're redefining the values each time you call the file (with an ugly dofile no less)

local health -- This is local to the whole file

function class.getHealth() -- Renamed to avoid confusing, replaced ob:meth() with ob.meth() syntax because that's not how closures are used
  return health -- This returns the value, so health is closed to the file, but can be "read" with this function
end

return class