In the inaccessible plateau of Hor-Nushan, there was always little crime. But in late autumn comes a maddening wind, that can drive the best man crazy, if only for a short time, make him turn on himself or others. For murder, the locals have devised a special punishment: the murderer has to dig a well for the family of his victim. The area is very dry, and having a good well is a source of wealth and prestige. In this way, the murderer atones for his deed and repays the family; perhaps they even find peace.
Culture/Religion: based on fear and respect. Gods are very dangerous creatures, sometimes friendly, often not. Temples are the way to make contact with them... if not easier, then at least more concentrated in one place. Were it not for the temples, gods could be running amok among the people. Therefore, mortals have to keep the gods close to temples, entertained and worshipped. It doesn't make the bad ones any friendlier, though (and is no guarantee some won't go on trips now and then). Still, there have to be priests that are hardy men, able to survive the rigours of their position, get a sufficient number of worshippers to make the gods feel important enough, and mediate the contact between mortals and immortals.
There are crimes for which a man is not killed, but chased into the wilds, away from his home and country, to not return or be killed on the spot. In one culture is the condemned mutilated, and even his vocal cords are damaged so that the voice is unrecognizable to his friends and family. This is the punishment for people too obsessed with their own prestige.
What about a 'criminal' society with distinct laws - for stealing, the larger the value of something stolen, the less punishment the courageous thief recieves (but must return it of course). For this pirates(?) caught petty thieves deserve to be punished harshly. If you take, you better take a lot.
Minor Cultural Modifier: The culture believes, for the soul to leave the body, the corpse' eyes must be open. So any member of that culture takes care any dead body they find has its eyes open. Doubly true for those they kill themselves, for then the corpse will surely rise as an undead hunting him.
As a new member of a magical organization you get 1-3 magical scrolls to do with them whatever you want. They are unmarked and contain spells you dont know and will only find out at the moment of reading=casting.
After building a new granary,it is customary to let a rat feast on grain. After that,there is chase and the rat is killed. Failing to catch this rat is a bad omen.
In this culture it is not wise to talk too much good things about anything - especially children,lest some evil spirit steals it. So it is customary to say it is ugly and weak and will surely not survive. Also:
"The man who boasts of his young woman is a fool,
The man who boasts of his wares will get rich."
The PCs encounter a strange set of artistic drawings done on the ground as they pass through a city. It has been done in chalks and no one saw who did it. Wizards might recognize the writing within the colored square as an obscure and dead language with a message stating that a prominent wizard and a retired bard have discovered how to populate Arcadia with the spirits of the dead!
Is it a local hoax, or are the PCs crossing the path of a very deranged and possibly dangerous mage?