“ A small, primitive village has yet to discover fire, which is a good thing because there are highly flammable (but not otherwise dangerous) gasses in the air. The heroes, blissful in their ignorance, don't know that and think it a wonderful idea to show the locals open flame.”
“ A village where everyone goes blind sometime during puberty. What could be causing this? Perhaps something in their diet. Or some malignant gene. How would an entire village where only young childen can see function?”
“ One of the PCs comes across a magical ring that grants some power but has odd aura as if cursed. Yet this curse is different than the standard curse. When the PC puts on the ring he/she suddenly feels married. There is now an illusionary woman, who he/she cares deeply for but who is also always very critical of the PC. The wife is demanding of attention and constantly giving the PC directions. The PC wearing the ring is the only one that can see and hear the bride. The curse can never completely be lifted. Even if the PC takes off the ring and somebody else puts the ring on; the PC will still be visited by the ex-wife at least once a month. During this visit she will demand money and apologies.”