“ Made from the tears of a bound goddess, this magical wine has the power to charm or dominate any who imbibe even the faintest quantity. Once affected, it remains dormant until the victim hears a special magical phrase, upon which they will be magically bound to the speaker. Enterprising villains could drop this into the water supply of an important city..”
“ Magic is like alcohol, the more that is used, the more it causes a hangover later on and the less judgement one has when using it. If one waits a while after casting a spell, things 'detoxify.' A cantrip or two is like a sip of weak beer, whilst a large creation spell is like a bottle of vodka. Cast something too big and you can die from magic intoxication.”
“ 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.”