Time-manipulating narrative tools work best when they have a point. Sometimes you can use time skips to "cheat" a weak story into something stronger. But some of the best stories have a point behind it.
Let me go over how I try to use prophecy and time skips. I think I need to use them more often. Time skips especially.
PROPHECY!This is something everyone ends up having to try their hat at. My favorite flavor of prophecy is specific though. Wherein the characters move forward in time, then they can come back with foreknowledge. Usually of some disaster. This is great for foreshadowing. It's also a great way to give players a way they can influence or alter the future.
The key to prophecy though, is to avoid specifics. Vagueness is best. A specific prophecy only works if it's the self-fulfilling kind. If a PLAYER wants a self-fulfilling prophecy, I could see that working.
But every time I've tried to have a "specific" prophecy, one that dictates the choices of a player, it doesn't work. Bad feels. Frustration. Justified feelings because I robbed a player of their ability to choose.
It's better to be vague. Avoid robbing players of their agency as a GM. Players, if you get the chance, try to write your own prophecies if your GM will let you.
TIME SKIP!This one I think all groups use on occasion. Time moves forward a bit, and you skip a bunch of stuff. Maybe a few hours in the game are skipped, to save everyone from having to RP breakfast. Or the campaign is skipped ahead years, where things have changed quite a bit.
Every time I've used a time skip, it's worked great for me. The only danger is missing the point of it. That is, if there is an established status quo after a time skip, something has to break it. Time skips are warranted for skipping over the minor things that aren't of interest to a game. These can be interesting character building bits of RP. But if they aren't part of creating arcs for characters, maybe it's better to jump ahead.
The goal should always be about characters changing over time. About them going from one state to another. Or if you game from a plot-focused direction, the same goes. If it doesn't move the story forward, maybe the skip current troubles in the Underdark.
I have found talking with players about what happened to their characters after a time skip helps us. We find out together what the new status quo is. There also is the need to make sure characters still have reasons to work together. That cohesion is sort of key to the collaboration of a group. If so, new characters find their way into the story if the old character is too far gone.
Time skips always seem to work for me. My players often seem to enjoy the chance to redefine their character. I like skipping the fat and getting to the meat of the interesting parts of a story.
How about you? Any success with prophecy and time skips in your games?