Historicly, we have had plenty of rl groups like the Taliban and the Puritans who supressed anything which was in any way fun. What if there was some group that was the opposite? (which in time would cause problems of it's own for the civilians under their control.)

In an isolated mountainous region, the local miners build their stone huts right next to the sarcophagi of their dead. In the winding tunnels of their mines, the spirits of their ancestors toil alongside them, sensing where the best deposits will be found and guiding their picks' strokes.

Nearly every primitive culture has had rituals and celebrations to guarantee the proper passage of the seasons and to ensure the fertility of crops and animals. Oversight of these ceremonies was generally the provenance of local kings or priests.

Suppose that the adventurers dispatch one of these fellows. The local peasants may become hysterical, fearing famine and death will stalk the land. Alternatively, they may want one of the new heroes to become king. For a while, this can be a good thing, but the first time that the crops fail, the superstitious locals will want to sacrifice their new leader.

Rich Romans raised fish in private pools at their villas. A favorite fish was lamprey, a parasitic fish which sucks off blood and flesh but made an excellent meal. A particuarly gruesome punishment for slaves was to be thrown into the lamprey pool, where their flesh was ripped from the bone by swarms of the jawless fish.

In ancient Rome, social appearance and respectability were everything. The most hated men were punished with damnatio memoriae, damnation of memory. Every trace that a person had ever lived was removed. Busts were shattered, freizes were marred, records were struck. Any sign of the hated figure was destroyed.

Pcs learn of high power magics that allow them to banish weapons and suits of armor to some 'elsewhere' place until such time as they need it. reduces encumberances, gets fewer questions, and when the PCs get jumped by thieves in the ally, they can summon their suits of full plate armor with weapons drawn.

Lesser powers would allow them to summon their weapons from another physical place, drawing them to their hands like Luke skywalker summoning his lightsaber on Hoth.

Medieval Britons didn't write contracts. Instead, men making agreements would clap their knives onto an altar and recite the agreement three times to seal a deal. Even after the Normans introduced written contracts, British nobles would wrap the parchment around a knife to authenticate it.

The religion believes in reincarnation, but that you will be reborn in the past. People of today are those re-born of tomorrow, with some discarded as trash. The most pure will be eventually reborn in the mythical paradise-like past, where people lived for hundreds, or maybe even thousands of years.

This goes nicely with beliefs into foresight (you know a little about the future because you have been there), but also to many complaints of how things are going always from bad to worse.

In 1500 B.C. in Egypt a shaved head was considered the ultimate in feminine beauty. Egyptian women removed every hair from their heads with special gold tweezers and polished their scalps to a high sheen with buffing cloths.

An example of a mythological worldview misinterpreting scientific practices occurred in Africa, where an aid organization, focusing on slowing and stabilizing population growth, distributed abacuses with red and white beads corresponding to a woman's menstrual cycle. Women were instructed to move one bead a day, only having intercourse on days represented by a white bead. However, the experiment failed, and the population grew in the households using the abacus. The women believed the abaci were magical, and that they would be protected from pregnancy by moving a white bead into the place of the red bead before intercourse.

The heroes are travelling the great seas by ship. One night when the seas are calm and everything seems fine their vessel is eaten by a great whale. The end? No. They wake in the belly of the animal, it is like a great cave. Full of wrecked ships and strange things to be discovered. Will they make it out alive?

Under the sewers of a large town ancient burial chambers are discovered. If the PCs investigate they fill find that a pale white flowers grows amongst the graves, in the dark.
How do they survive without light? What is their origin? Why in a burial chamber and not just in any old cave?
Can they be sold or do they have any special quality at all? It is up to the PCs to discover.

The members of the party has unknowingly been infected by a mysterious plague and have been spreading the virus for quite some time now while adventuring. They start to hear rumors of all the cities in quarantine after they travelled trough. Will they discover the source of this? Will people start to avoid them, try to kill them?

The greatest tree in the woods has a secret, there is a dungeon under it made from the intricate web of roots. What creatures could reside here? What secrets will the PCs uncover?

A city the heroes visit is in a crisis, the king and queen are getting a divorce. Who shall rule? The inhabitants of the city take sides by tying a red or blue ribbon to their swords, sticks etc. Whose side will the Pcs take?

A plague is spreading trough the lands, the plague is actually an old woman carrying a stick. She walks from farm to farm spreading the plague. Can the PCs stop her without getting infected.

The Macabre style of architecture is common in ancestor venerating societies, or societies that have been afflicted by a long term period of loss of life. The style is best noted for its use of a morbid and gruesome, skulls and bones, severed limbs and the like. It also alternately honors the spirits of the dead with stunning works of art, and mocks death through caricature and comedy. Macabre is the common architectural style in Ozea.

In a small, genetically isolated region it is not uncommon for the locals to have three arms. The third arm is generally a second right arm that is a good bit weaker than a normal arm and is generally held against the chest. This hird arm is most often used to carry small things, though some of the more skilled craftsmen have learned little tricks with their third arm.

What if dragon-sightings and evidence of such was treated with the same skepticism and mockery as modern UFO sightings? More for a low magic world where dragons 'dont' exist.

In an area albinos are considered to be evil mystics and locals ward themselves against them by turning their backs to them to avoid being mesmerized. Suddenly the angeliclly pale loner with white hair and violet hued-eyes is suddenly an outcast, and his companions are treated as if they have been mystically bonded into his service, and could be treated with attempts to intervene or given the same stony treatment. Expect poor quarters, no hospitality and to pay twice as much for everything.