An army and navy who work in the same way as others except their rank titles are upside-down. So people start as full generals and those with the rank of private command armies.
In a deeply unsettled world, much of it anarchistic or ruled by murderous gangs, a group have adopted the armour, weapons and discipline of an army of the distant past.
Magical curses are rarely cast, as if cast on someone for fun or purely maliciously and the person cursed has not done something seriously wrong, it tends to ricochet back on the curser. Therefore the few who do get cursed are shunned by most people as genuinely guilty,and few will help them.
A country where noone can be executed whilst telling a story provided it's reasonably interesting.
The words of a wedding vow contain a strong love spell which enchants both the people who says it, so they will allways be deeply in love with each other.
Have the PCs rping Orcs or Goblins or some other race that normally exists only as things to cut up with swords.
If you possess someone, you have an hour to get back to your own body or your thoughts will be overwritten by that of the orginal person
Magic is like alcohol, the more that is used, the more it causes a hangover later on and the less judgement one has when using it. If one waits a while after casting a spell, things "detoxify." A cantrip or two is like a sip of weak beer, whilst a large creation spell is like a bottle of vodka. Cast something too big and you can die from magic intoxication.
For the people of Kuboloth, hell is not in the depths of the earth but in the cold of the windy air;heaven is in the warmth of the earth, lit by glowing jewels.
Little halflings are told that if they don't behave, a demon called Santa Claus from a hell of ice will kidnap them and force them to toil making toys.
Magic is impossible except for a handful of days in the year, when those with the knowledge become hugely powerful.
A magical stave with two distinct uses. One end is a healing stick, which can heal some quite serious diseases, the other half can be used to inflict those diseases on other people.
In a room the PCs find a decomposing body half in and half out of a mirror, the result of an attemp to create a [Mirror Golem] that went horribly wrong.
The more you dominate your life to a god or goddess, the more you gain magical powers from him or her, but the big stuff does not come easily. Most worshippers have only the weakest of spells.
The PCs accidently start a fire and are caught by the local law enforcement. Since it was accidental, the punishment for the PCs is to fight the fire. Providing they can put it out before it burns down the town, they will not face any further punishment.
What if casting magic changed (for a few hours or days depending on the strength of the spell) the colour of the skin of the spellcaster? It could lead sadly to a very racist world to rp in.
A magical weapon which the third time it is used will turn on it\'s owner, killing or badly wounding him or her.
A healing potion which if drank by males (or women in male clothing) causes a short term (1 d6 hours) urge to dress in girl's clothing due to the high levels of estrogen in it.
A ghost is haunting someone with a secret-it\'s not that he murdered the person that became a ghost, it\'s that he went into hiding with a new identity to avoid being murdered, whilst the ghost wants him to join her in the afterlife. The ghost is getting stronger and more dangerous each day. Enter the PCs.
An orc male who dislikes the hard warrior life, has disguised himself as an orc female and is learning how to become a Shaman. If uncovered as a male, his fellow orcs will be disgusted enough to kill him.
What to export or import....
Fabric: wool, linnen, silk...
Wood: raw-material, furniture
Metals: iron, gold, silver, copper...
Wine, beer, mead, spirits...
Animals: horses, sheep, swine, cows...
Coloring-powder (for fabric, ink...)
Raw-material to make fabric: unprocessed wool, linnen, silk...
Glass: Windows, figurines, glasses, raw-material...
Tea (not sure about my spelling here, but I mean the hot drink Englishmen drink instead of coffee!)