Laws are sand, customs are rock. Laws can be evaded and punishment escaped, but an openly transgressed custom brings sure punishment.
My Take - Your average person probably can't recite the laws of their society too well, but they for sure can tell you just what the customs and taboos of the tribe are. People will forgive breaking the law if it isn't too bad or you pay enough blood money. Break customs and either learn to run from the mob really fast or be prepared to defend your life against the whole tribe. To sum up: learn the customs of the tribe before you worry about what their laws are. The sheriff might give you crap for jaywalking, but he might just throw your butt in jail over spitting on the sidewalk.