The dice in Monster World consist of two ten-sided die, numbered 0-9. One die's roll is multiplied by ten and added to the other die's roll, making it possible to roll any number between 00 and 99, with the lowest numbers considered the best. It is more important for the die representing the tens to stop on a low number, than the one represent the ones, so the double roll takes advantage of using the ones die to get the tens dice to stop on a low number.
Each die has five even numbers grouped on one face and five odd numbers grouped on the opposite. By spinning the die representing the tens with the even side up, the chances of rolling a number between 00 and 09 is increased to 1 in 5.
By putting a weaker spin on the dice representing the tens, it will stop before the dice represents the ones. If it stops on an undesired number, the player can vibrate the table to get the ones dice to strike the tens dice and change its number.
Dark Bakura was believed to be using this technique against Yugi and his friends when they played Monster World and rolled a number of critical hits. After Dark Yugi began rolling for Yugi and his friends, he too started using the double hit to get critical hits. Once Dark Yugi exposed that they had both been manipulating the dice rolls, he and Dark Bakura agreed to drop the dice out of their hands when they roll in future to prevent abuse.
- Yu-Gi-Oh! Duel 54: "Millennium Enemy 5: Stop the Run of Criticals!"