Your protagonist, a blacksmith, starts releasing unfinished alpha and beta versions of weapons for customers to test before they go into production.
Your villain writes a letter to your protagonist, calmly asking him to join her on the dark side. Because the letter is eloquent and well-reasoned, your protagonist accepts.
An hour into your protagonist’s epic quest to save the world, she breaks her legs and has to do it all in a wheelchair. No magic healing.
A guard who was late for work finds out all the other guards got killed by a “prophesied hero.”
A magic system allows its users to see underground, detecting mines, tunnels, and subterranean creatures.
Heroes are chosen at birth, but they have to be heroes their entire lives. They can’t choose to be farmers or cooks or anything. All they can do is fight monsters and villains.
A magic system that only works when mages bash their heads against hard things, like walls and roads and desks.
The prophesied hero is not a spunky or brooding teenager. S/he’s old, around 100.
Put airplanes in a fantasy along with magic.
(Got the prompt order mixed up a bit. Will skip a day and post #47 Friday.)
Tell a story without any dialogue, but let the story center on the power of words.