Efronsitive

A set of nontransitive dice. A set of nontransitive dice is a set of dice for which the relation "is more likely to roll a higher number" is not transitive. See also intransitivity. This situation is similar to that in the game Rock, Paper, Scissors, in which each element has an advantage over one choice and a disadvantage to the other.

There are three different kinds of nontransitive dice generated by this library: Efron, Grimes, and Miwin.

Efron's Dice
http://en.wikipedia.org/wiki/Nontr