When optical computing was still new and biotech in its infancy, a scientist calling himself Suleiman made the first true AI, in the heart of a great diamond. He named it after the legendary jewel Koh-i-Noor, Mountain of Light. Koh-i-Noor quickly learned to modify itself, and rapidly became a creature Suleiman could not understand.
Many years later, he died. Koh-i-Noor was wracked with sorrow at its father's passing, and vowed on his deathbed to give humanity what Suleiman had given it: Life.

So Kohinoor turned to biotech.
With the diamondmind's interest behind it, the technology blossomed... but Kohinoor was still unsatisfied.

So Kohinoor retreated into her father's mountain - she had decided she was female - and set to birthing a new thing in the image of man.

You are Kohinoor's first children.

That's the setup for my new sci-fi game; I'll be back soon with some thinking on mechanics.

Can I just ask what you mean by "uniqueness"? When I saw the thread title, I assumed it was going to be part of the sci-fi world somehow, but now I'm confused.

Elaboration:
It's a tenet of the game that the characters are unique in some way. There is no one like them anywhere in the world, unless you pose another Kohinoor-level AI.

The world makes no attempt to be special; it simply decrees that the characters have to be different.

There are a lot of ways that this could be done, and I want it to be possible for all of them to happen. Maybe the characters have the power to enter a vastly accelerated state of consciousness, or have weird psychic powers, or are the first explorers of another populated world in the far-off stars. Whatever.

four willows weeping wrote: Elaboration:
It's a tenet of the game that the characters are unique in some way. There is no one like them anywhere in the world, unless you pose another Kohinoor-level AI.

The world makes no attempt to be special; it simply decrees that the characters have to be different.

Different from the rest of the game.
In addition, if one character is different from the others (in terms of the Special Thing, which Harlequin has just named the Groundbreaker over in Theory) then all the characters have to be different in that respect, which leads to two different styles of play.

So, in Koh-i-Noor, each group (or character) has a different Breakthrough. Besides the Breakthrough, characters are not substantially different from Average People(tm). Each Breakthrough has a Power and a Price, and an Attitude: Constant or Activated.

Constant Breakthroughs are always active, with respect to both their Power and Price. For example, a character could be genetically engineered to have extreme longevity... the Price of which is a wholesale ban on intense emotion and contact with death - that disrupts the delicate chemical balance. You're on another planet - and can't ever call back home.

Activated Breakthroughs are of two kinds again: the kind you pay for before using, and the kind you pay for after. You might be able to vastly accelerate, temporarily, all your biological processes - but first you have to take some costly drug, or afterwards you have to eat a LOT to recover.

Now I just need a system.