The common-law legal system forms a major part of the law of many countries, especially those with a history as British territories or colonies. It is notable for the inclusion of extensive non-statutory law reflecting a consensus of centuries of judgements by working jurists.
As far as my understanding of common law is concerned, it is a set of rules that has evolved out of common sense being aplied by sensible people to events which need clarification, but not at the Country's legal level.
I.e a sub-strata of legal rules to obviate the need for legislation on minor matters.