A pair of dice which have the same odds for throwing every number as a normal pair of 6-sided dice. They are the only such alternate arrangement if face values are required to be positive. However, if faces are permitted to have zero value (i.e., to be blank), then two additional possible equal-odds pairs of dice are obtained by subtracting one from each face on either of the two dice and adding one to each face the other. If negative values are permitted, there are an infinite number of equal-odds dice.
Sicherman Dice
See also
Dice, Efron's DiceExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Sicherman Dice." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/SichermanDice.html