A species that lives off of either kinetic or potential energy.
A society in which everyone is sickeningly happy about everything.
A world in which technology “advances” backward for whatever reason: it starts off with laser tech and cures for cancer, yet regresses to sticks and stones over several thousand years.
A world in which alternate universes collide, one where the evil overlord destroyed everything, and another where the heroes of prophecy saved everything. This creates an odd in-between state where it appears nothing ever happened, yet all parties involved feel like they’ve accomplished something.
A society in which most citizens are so comfortable that they have to inflate small problems into huge issues, and even make up their own problems at times to feed their desire for drama. This society is suddenly bombed, leaving only a handful of survivors. Tell their story.
A messaging system that works via a long string of people from starting point to destination. Like the game Telephone, but with a little more at stake. And I suppose they can use pen and paper, so not like the game Telephone at all.
A world in which “the gravity of the situation” is not just a saying: grave situations literally have gravity that weighs down everyone involved.
A death system wherein people who die spend eternity in the afterlife, unless they gather enough favor with the god of their choice, in which case they can return as a prophet or angel.
A world in which shapeshifting is possible, but with one big catch: you can only shapeshift into your greatest fear.
A hotheaded warrior returns home from his journey of self-discovery and enlightenment, having learned the value of non-violence and the power of words. He walks into his house to discover his wife with no less than five other men. What does he do?