I am sorry if this issue has been already addressed previously in this forums, but I have been looking for old threads on the subject and I haven't found any specific to the matter. If anyone knows about any, please let me know and sorry again. Otherwise, this is my question: "Is Quantum theory complete?" If I am not wrong, this was Einstein's point in the famous letter to Bohr in 1920. According to Bohr quantum theory is complete because what is to supposed to be left in the theory (hidden variables) is also left in the very reality. Ok. I understand it, and I already know and accept that there are important reasons to debunk hidden variables. Nevertheless, I still have a doubt. When a measurement takes place an unpredictable value is obtained (under certain circumstances of uncertainty). How can we say that quantum theory is complete and at the same time that quantum theory cannot predict accurately the outcomes of a measurement? This is the very point I don't understand. Reality is given us the accurate outcome, whilst quantum theory is not, so reality is in fact "more complete" than quantum theory! Call me "retro" and "stubborn" but I sincerely still think Einstein was right about this point, but at the same time I am ready to open my mind to reasonable statements about the completeness of Quantum Theory. Thanks in advance.