title: how safe is object oriented Lua?
body: <p>Lua beginner here, i am looking into lua. 
  my question is: since an object in Lua is just a table,
  new fields can be added at runtime. if I have a typo in the code, and instead of changing a field, I create a new field, won't that bring mayhem? ;)
  I would only be able to figure out the bug in runtime, if I even get to that point in the program.
  (of course the table concept has other benefits like meta programming without reflection, but my question is about "safety" or predictability.)</p>
  
  <p>Is that the right conclusion?</p>