Prophecies are a very common element among fantasy stories.
I can hear you now.. “Cliche! It’s been done to death. Prophecies are so predictable (ha, get it?).” When paired with a protagonist that happens to be the ‘Chosen One’, yeah, I agree. This is a hard one to pull off in a fresh way. However, prophecies and predictions are present in almost all ideologies–religious and otherwise–although they’re not always described that way.
A belief of any sort usually includes a consequence that is meant to persuade others to adopt that same belief. The threat of destruction is a favorite (the burning of the wicked by the messiah, our planet becoming uninhabitable by the exhaustion of its resources, etc). The threats are often paired with promises (paradise, nirvana, personal or generalized peace) if the warnings are heeded. Sometimes they’re as vague as “the bad stuff won’t happen”.
So, in essence, a prophecy says “Dude, [this thing] is gonna happen if you don’t listen up and [do this], but if you do listen, [this stuff] will happen.”
This can also take the variation of “This [prophesied person] is gonna come and [do something].” More often than not, the coming of a prophesied person is considered inevitable, but the consequences of their actions may or may not be avoided. So, assuming you want to create a prophecy, how does one go about this?
1. Determine what it is your prophecy is predicting. The birth of a Messiah? The End of The World?
2. Decide whether or not the prophecy is inevitable.
3. Establish who the prophecy is aimed at. Who’s going to reap the consequences, for good or ill?
4. If your prophecy is not inevitable, what behavior will avert/invite the consequence?
5. Who is doing the prophesying? While this often doesn’t come up in the actual story, it can help you decide what tone to give the prophecy. Is the prophet a follower of the prophesied one? Someone who is eagerly anticipating the destruction of the unworthy? This will help you decide whether it’s a “Hahaha, you’re all gonna burn!” prophecy or an “Oh, happy day!” prophecy.
Now that you’ve got those basics covered, we’ll talk about creating the actual text of your prophecy in Prophecies, Part 2.
Note: The examples I’ve given aren’t intended to mock or belittle real world beliefs. They’re simply included for the purpose of understanding the concept and components of a prophecy.