From the introduction: Under regular use, the random magical potion has no adverse effects upon its imbiber and multiple potions of the same type will consistently produce similar results. Some of the potion's effects may be unwanted or less than desirable, but generally speaking all potions work as expected. The expensive and exacting process of distilling a potion is designed to harness the chaotic raw power of magic and to mitigate adverse effects. This work can easily be undone by simply mixing these otherwise stable magical concoctions. If someone was unwise enough to imbibe two or more potions from different sources (i.e. Different potion types or potions of the same type from different production batches) there is a base 10% chance of a wild & unpredictable adverse reaction. It takes some time for the body to metabolize potions, so this possibility exists while under the 1st potion's effects and for one hour afterwards...