What are the laws Governing Waknuk in The Chrysalids, if there are any?

Waknuk is governed by two main texts: the bible and Nicholson's Repentances.

Only Nicholson's Repentances had come out of the wilderness of barbarism, and that only because it had lain for, perhaps, several centuries sealed in a stone coffer before it was discovered. And only the Bible had survived from the time of the Old People themselves.

Rules for the image of man:

'And God created man in His own image. And God decreed that man should have one body, one head, two arms and two legs: that each arm should be jointed in two places and end in one hand: that each hand should have four fingers and one thumb: that each finger should bear a flat finger-nail. . .'

Rules an Offence or a Blasphemy:

The occurrence of an Offence was sometimes quite an impressive occasion. Usually the first sign that one had happened was that my father came into the house in a bad temper. Then, in the evening, he would call us all together, including everyone who worked on the farm. We would all kneel while he proclaimed our repentance and led prayers for forgiveness. The next morning we would all be up before daylight and gather in the yard. As the sun rose we would sing a hymn while my father ceremonially slaughtered the two-headed calf, four-legged chicken, or whatever other kind of Offence it happened to be. Sometimes it would be a much queerer thing than those. . . .

Nor were Offences limited to the livestock. Sometimes there would be some stalks of corn, or some vegetables, that my father produced and cast on the kitchen table in anger and shame. If it were merely a matter of a few rows of vegetables, they just came out and were destroyed. But if a whole field had gone wrong we would wait for good weather, and then set fire to it, singing hymns while it burnt. I used to find that a very fine sight.

It was because my father was a careful and pious man with a keen eye for an Offence that we used to have more slaughterings and burnings than anyone else: but any suggestion that we were more afflicted with Offences than other people hurt and angered him. He had no wish at all to throw good money away, he pointed out. If our neighbours were as conscientious as ourselves, he had no doubt that their liquidations would far outnumber ours: unfortunately there were certain persons with elastic principles.

So I learnt quite early to know what Offences were. They were things which did not look right -- that is to say, did not look like their parents, or parent-plants. Usually there was only some small thing wrong, but however much or little was wrong it was an Offence, and if it happened among people it was a Blasphemy -- at least, that was the technical term, though commonly both kinds were called Deviations.