NOD Theory was created by an individual during a lecture at University of Canberra. This individual was bored with the content of the lecture and decided to spend the rest of his time picking up chicks, this is how the Nod Theory was created.
The Nod Theory is when you make an eye connection with an attractive young female, look at them for several minutes indicating you attraction, while having a smooth and sexual smile on your face. You later make a second connection with the female and give her the "Nod" indicating, How you doing? Im into you, lets chat!
Bro you know that hot chick in Organisation Performance, i gave her the "Nod" from the NOD Theory Doji created and she was all over me after class.