“ What is a king to do? A prophesy indicates that a certain person is involved with the death of the king, but the prophesy was unclear as to what role - do they cause it or prevent it.”
“ A massive trebuchet constructed by the reigning tyrant, it can hurl the heaviest loads of any trebuchet to date and is the most destructive, non-magical weapon currently in existance. The Thought of Warwolf setting up on their lawn has quelled many a rebellion.”
“ The PCs are accosted in a major city containing at least one famous fortuneteller / prophet of the future. They are informed that their as-yet-unborn child will (insert terrible evil), and that, although they are very sorry, the PC must be executed to keep this from happening.”