Rule number 2
A basic understanding of how chords work, what chords can go together, understanding about the major scale and the relationship between scale and chords. A good basic working knowledge relating to the playing of the guitar or any instrument for that matter.
Rule number 3
The development and training of the fingers so that they respond automatically with no effort, simply put is called Muscle Memory.
Rule number 4
The art of doing, reading about it and talking about it is not enough, you need to Do It
This includes Practice and just playing the guitar.
Many people can practice a lot but still achieve very little, why? Because it is easy to sometimes end up practising the wrong things, having said that all practice is good if the fingers are working, but there are specific things to practice that enable a much faster success rate, and not grind you into a rut.