Efron's Dice

This is the set of non-transitive dice invented by Bradley Efron.

Red die: 4,4,4,4,0,0
Yellow die: 3,3,3,3,3,3
Green die: 6,6,2,2,2,2
Blue die: 5,5,5,1,1,1.

Two players choose a die each, cast them, and the player who gets the highest number is the winner. What is special about these dice is that none of them is the best. For each die there is another that beats it with a probability of 2/3. In this case red beats yellow, yellow beats green, green beats blue and blue beats red.

So, contrary to intuition, the player with the advantage is the one who chooses die second. Useful to show this unexpected property with a game. More info in https://en.wikipedia.org/wiki/Nontransitive_dice.