If I brew a potion of lightning bolt, what happens when someone drinks it?
- Lightning bolt strikes them?
- They can cast a lightning bolt?
- They emit lightning that strikes where they point?
- Nothing happens?
Same thing with vampiric touch: Would the consumer covert their hit points to temporary hit points? Would that mean that drinking a healing potion after the potion of vampiric touch gives the character full hp + temporary hp without touching anyone?