Although it would be incredibly hard to make it work in a game setting, this discussion on prophecies makes me want to do the opposite, a Cassandra thing, where a prophecy has been made, doubted, fulfilled down to the smallest detail, and the characters insist Cassandra just got lucky, anyone could do it, and there is no reason to believe anything else Cassandra says. Even as every bit of Cassandra's latest prophecy comes true, they argue Cassandra's a fake and refuse to act on any info they've been given.

Maybe make part of game play? You get XP every time you act against the prophecy and get penalty points on rolls for actions trying to take advantage of what you've been told?