The first rule, because of the fear of failure, you do not mention it.
But it was ineffective against Jiang Shu, for his performances were nearly always assured of success.
The second rule, for fear of being figured out upon a second performance, you do not perform it again.
However, this too was ineffective against Jiang Shu; he simply wouldn't perform a second time.
Performing the same magic act twice was too dull for him, besides, he had long past the phase of accumulating performance experience.
The third rule, the crux is that the secrets of magic should not be gratuitously imparted—it's actually about protecting the interests of the magicians' industry.
Yet still, ineffective against Jiang Shu. In Lonely City, he was the sole magician, and moreover, he understood these matters far better than anyone else.
No one! Understands magic better than I do!
