Also referred to as Doubling Cube or Doubling Block. It is a die shaped object, with numbers on all six sides, going from 2 to 64. At the beginning of the game the cube is placed in the middle, and both players have the option of doubling the game.

In case of doubling the player has two options: declining or accepting. If a player declines the cube, he loses the game, but when the cube is accepted, the stake of the game is doubled. As you can see the cube is not very important from the point of view of the game itself, but it is very important if you consider the doubled or even redoubled stakes.