“ What if potions and tonics had negative side effects? Potions of increased strength cause violent tempers, or damage joints. What if potions of dexterity caused tremors, or palsy?
What if they were addictive, and had withdrawal symptoms?
Could someone make a bad batch? No one use the brown strength potion!”
“ The heroes stop in a small town ready to restock their traveling supplies and feed for their animals. All of the villagers are starving, and there is no food to be had. If the PCs are quick witted, their noble steeds might be slaughtered for food.”
“ Somewhere along the line, someone very powerful lost their marbles. Literally. Possessing a marble allows incredible clarity of thought about a particular related subject.”