Gerolamo Cardano's Dice

Origins
Gerolamo Cardano was an Italian polymath who helped make the basic rules of probability. He was known to be a gambler, so when he was short of money he would play chess and other games. Cardano's understanding of probability allowed him to bet on the most likely events, letting him win more than his opponents.

Effects
When rolled, the dice imbues the person with an understanding of probability and in certain situations, which outcome is more likely. However, if the user desires something harder to come true, then the dice can let that happen when rolled again. The downside is the user turns into a compulsive gambler with repetitive use.